TWI878990B - Round counting system for firearm with detachable magazine, non-transitory, tangible computer readable storage medium and method of manufacturing round counting system - Google Patents

Abstract

This disclosure describes systems, methods, and apparatus for detecting and displaying a number of rounds in a firearm magazine comprising a maximum number of N rounds. The magazine may comprise a follower, magnets on the follower, and <N magnetic switches arranged along a path of the magnets when the follower moves along a length of the magazine, the switches configured to activate based on a magnetic field exceeding a threshold, and a first antenna arranged on an inside of the magazine and parallel to a firing direction of the firearm, and configured to wirelessly transmit a round count indication to a second wireless antenna on the firearm, the round count indication based on the round count data, the second wireless antenna affixed to an inside of a magazine well of the firearm and mostly overlapping with the first antenna.

Description

Ammunition counting system for a gun with a detachable magazine, non-temporary tangible computer-readable storage medium, and method for manufacturing an ammunition counting system

The present invention generally relates to firearm ammunition/bullet counting. Specifically (but not limited to), the present invention relates to systems, methods and apparatus for wirelessly counting the number of ammunition remaining in a magazine.

U.S. Patent No. 9,612,068 discloses a magnet (180) that can be coupled to a spring to support a deflector and a signaling element (145) that is coupled to a magazine or another portion of a gun and configured to detect a proximity of the magnet (180). For example, the signaling element (145) can include a reed switch or a Hall effect sensor. The proximity of the magnet (180) is converted by the signaling element (145) into a signal indicating the state of the bullets in the gun (105). The signaling element (145) can then send a wired or wireless signal to a reporting element (130, 135) to display a remaining ammunition count to the gun user. There is no sensor in the magazine.

U.S. Patent No. 9,784,511 discloses a magnet (33) on a detent (38) or compression spring (34) that causes a tactile indicator (44) to physically displace on an exterior of a magazine to thereby provide a tactile indication of the detent position within the magazine.

U.S. Patent No. 8,215,044 discloses a Gray-coded ferromagnetic strip disposed along a magazine to indicate a position of a deflector and thus indicate the ammunition count of a magazine.

International Patent No. WO2018172738 discloses an ammunition counting device for monitoring the number of ammunition contained in a gun magazine. The system includes a magnet mounted to a deflector and a plurality of reed switches arranged in a spaced arrangement along a length of the magazine. When the deflector is in a given position, the adjacent reed switch is activated and a signal indicating the number of ammunition in the magazine is provided.

U.S. Patent No. 5,303,495 discloses a pistol having a grip that completely encloses a magazine. The gun also includes a permanent magnet (92) mounted on a top crosspiece of a spring 93 and a series of Hall effect switches (94) surface mounted on a mylar substrate (95) in the hollow handle of the gun. The number of Hall effect switches (94) is equal to the number of cartridges to be counted, and the switches (94) are positioned one cartridge diameter apart at a position where the magnet (92) will be positioned directly adjacent to a switch 94 when each cartridge is fired. One Hall effect switch (94) is activated each time. There are no sensors in the magazine.

U.S. Publication No. 20110252682 discloses a receiver member (41) (e.g., a Hall effect sensor) in a handle or magazine chamber of a long gun, which senses a magnetic field strength of a magnet (24) positioned on a cartridge elevator (22). In the case of a long gun, the present invention proposes that only the last cartridge in the magazine (21) needs to be monitored, so the receiver member (41) is placed in an area adjacent to the upper portion of the magazine (21) (i.e., in the magazine chamber). There is no sensor in the magazine.

The following presents a simplified overview of one or more aspects and/or embodiments disclosed herein. Thus, the following overview should not be considered a broad overview of all aspects and/or embodiments, nor should the following overview be considered to identify key or critical elements associated with all aspects and/or embodiments or to limit the scope associated with any particular aspect and/or embodiment. Therefore, the following overview is only used to present specific concepts related to one or more aspects and/or embodiments of the mechanism disclosed herein in a simplified form before the detailed description to be presented below.

Some embodiments of the invention may be characterized as an ammunition counting system for a firearm having a detachable magazine, the system comprising a magazine, a deflector, the deflector comprising one or more magnets, and the magazine comprising: magnetic switches disposed substantially along a path of the one or more magnets as the deflector moves along a length of the magazine, the magnetic switches configured to activate based on a position of the one or more magnets relative to the magnetic switches and a respective magnetic field at the magnetic switches exceeding a threshold value; and a first antenna disposed at a position configured to be at least partially mounted on the deflector. The first antenna is configured to wirelessly transmit at least one of an indication of one or more active magnetic switches of the magnetic switches, ammunition count data, or an indication of an ammunition count to a second antenna on the gun, wherein the first antenna wirelessly receives power from the gun, and wherein the power from the gun is used to power the magnetic switches, and wherein the second antenna is configured to be attached to an interior of a magazine chamber of the gun and has an area that substantially overlaps with an area of the first antenna.

Another embodiment of the present invention may be characterized as a method of retrofitting a magazine with an ammunition counting system, the magazine including an ammunition deflector, the method comprising: mounting one or more magnets on the ammunition deflector; substantially disposing <N magnetic switches along a path of the one or more magnets as the ammunition deflector moves along a length of the magazine, wherein N is a maximum number of cartridges that can be loaded into the magazine, the magnetic switches being configured to be activated based on a position of the one or more magnets relative to the <N magnetic switches and a respective magnetic field at the magnetic switches exceeding a threshold value. value to activate; a first antenna is arranged in an area of the magazine configured to be at least partially mounted in a magazine chamber of the gun and parallel to a firing direction of the gun, the first antenna being configured to wirelessly transmit at least one of an indication of one or more active magnetic switches of the <N magnetic switches, ammunition count data, or an ammunition count indication to a second antenna on the gun, wherein the first antenna is arranged so that an area of the first antenna defined by a height and a width is primarily aligned with an area of the second antenna coupled to an interior of a magazine chamber of the gun.

Yet another embodiment of the present invention may be characterized as a method of manufacturing a magazine having an ammunition counting system, the magazine including a deflector, wherein the deflector includes one or more magnets, the method comprising: disposing <N magnetic switches substantially along a path of the one or more magnets as the deflector moves along a length of the magazine, wherein N is a maximum number of cartridges that can be loaded into the magazine, the magnetic switches being configured to activate based on a position of the one or more magnets relative to the <N magnetic switches and a respective magnetic field at the magnetic switches exceeding a threshold value; disposing a first antenna at the configured The first antenna is configured to wirelessly transmit at least one of an indication of one or more active magnetic switches of the <N magnetic switches, ammunition count data, or an indication of an ammunition count to a second antenna on the gun, wherein the first antenna wirelessly receives power from the gun, and wherein the power from the gun is used to power the <N magnetic switches, wherein the first antenna is configured so that an area of the first antenna defined by a height and a width is primarily aligned with an area of the second antenna coupled to an interior of a magazine chamber of the gun.

Yet another embodiment of the present invention may be characterized as a non-transitory tangible computer-readable storage medium encoded with processor-readable instructions to execute a method for detecting and displaying the number of cartridges remaining in one or more firearm magazines, each firearm magazine comprising: a deflector including one or more magnets; a magnetic switch that is activated when the deflector moves along a length of the magazine; The method includes: assigning one or more unique identifiers to one or more first antennas, wherein each unique identifier is associated with one first antenna; identifying a respective ammunition for each gun magazine inserted into a magazine chamber of the gun; and a count indication; temporarily storing the respective ammunition count indication and the unique identifier of the first antenna assigned to the respective gun magazine for each gun magazine inserted into the magazine chamber of the gun, wherein a second antenna is configured to receive the unique identifier after the respective gun magazine is inserted into the magazine chamber; and displaying the respective ammunition count indication of the one or more gun magazines on the gun , wherein the user interface is selected from the group consisting of: a number displayed on a red dot scope or a sighting display, a frequency of a flashing light, a color of one or more lights, a number displayed on a multi-pixel display, a number of LED lights lit on an LED display, an audible signal, a fuel gauge indicator, or a bar graph indicator. The user interface may also reside outside the gun, such as in augmented reality glasses or a commander's display, to name two non-limiting examples.

In some aspects, the present invention alleviates some of the problems that have remained unsolved in the industry for more than 30 years by combining some or all of the following: (1) using a Hall effect switch instead of a Hall effect sensor; (2) deploying the Hall effect switch along the entire length of a deflector path so that there is consistent signal strength and high signal-to-noise ratio at each cartridge position; (3) deploying a magnetic sensor or switch in the magazine, wherein the magnetic sensor or switch (4) placing a planar or "thin" (e.g., about 2 mm to about 6 mm thick) near field communication (NFC) antenna in the magazine compartment; (5) placing a processor in the magazine to process the sensor signal before transmitting it across a wireless connection; and (6) harvesting energy from a power source such as a battery on the gun through the NFC connection.

(1) Hall Effect Switch

Most systems rely on Hall Effect sensors rather than Hall Effect switches to detect a magnet in a flipper because these more advanced sensors can better determine a position of a magnet in a single use (e.g., a Hall Effect sensor provides an analog signal that is proportional to magnetic field strength and therefore distance, while a single Hall Effect switch provides a high or low signal that varies with a critical magnetic field). For purposes of the present invention, a "Hall Effect Switch" is a magnetic switch configured to provide a digital or at least pulsed or square wave output that is compared to a waving or sinusoidal analog output by a "Hall Effect Sensor." In some scenarios, Hall Effect sensors are susceptible to many of the variables mentioned above relative to the Radetec socket. Systems using Hall Effect sensors typically require user calibration due to their susceptibility to these variables. Additionally, Hall Effect sensors also require an analog-to-digital converter (ADC) to process their signals, which increases the computational complexity of a system using these sensors. The inventors of the present invention unexpectedly discovered that simpler Hall Effect switches, when used in an array of <N magnetic switches (or N/2) (where N = the maximum number of cartridges in the magazine), do not require an ADC and calibration and can provide more accurate detent plate position than an array of Hall Effect sensors with a number equal to or greater than the number of cartridge positions in the magazine.

To implement a Hall effect switch array where the number of magnetic switches is <N, a processor can be used to evaluate the signal from the array and seek two solutions: (1) when only a single magnetic switch or Hall effect switch is active, the deflector plate may be closely aligned with the magnetic switch or Hall effect switch; and (2) when two magnetic switches or Hall effect switches are active, the deflector plate may be located approximately between the two magnetic switches. Using these two solutions, the processor can distinguish each cartridge position even if <N or N/2 or N/3 or N/4 magnetic or Hall effect switches are used. In some cases, reducing the number of switches can also be used to reduce cost and complexity.

Another advantage of using magnetic or Hall Effect switches is that the processor can analyze the switch output and determine a number of cartridges without storing any state or other data in memory. Therefore, in some embodiments, a processor with less or no cache/memory may be implemented. Alternatively, this implementation may allow a processor with cache/memory to optimize cache/memory usage for ammunition count processing.

(2) Sensors arranged along the entire length of one magazine

While Hall Effect sensors can be used to estimate the distance to a moving magnet using a single sensor, these systems also introduce errors because each cartridge position must be associated with a unique magnetic field strength. By positioning magnetic field sensing sensors along the entire length of a magazine, the sensors can be configured so that each cartridge position can be associated with a consistent magnetic field strength to greatly reduce errors. This also helps avoid the calibration challenges seen in prior art.

(3) Sensor inside the magazine

Most existing systems use sensors outside the magazine because this simplifies manufacturing and design. This also avoids the challenge of having to wirelessly transmit data from the magazine to the gun. However, in some instances, these systems are not accurate enough for practical implementation, which can be overcome by choosing a more complex route to position the sensor inside the magazine. For example, U.S. Patent No. 9,612,068 vaguely mentions that ammunition count information can be wirelessly transmitted to a display, but does not provide the beneficial details surrounding this so-called wireless implementation. WO2018172738 also vaguely indicates that a wireless chip can be implemented, but does not further discuss the relevant details required to implement this wireless implementation. Thus, the challenges associated with acquiring ammunition count data from a magazine to a gun are not addressed in detail in this art. Aspects of the present invention relate to achieving more consistent magnetic field strength measurements, for example, by providing little to no material between the magnets of a deflector and a magnetic field strength sensor. Additionally, the strongest possible magnetic field may be picked up by positioning the sensor or switch closer to the deflector than in the prior art, which may also be used to minimize errors.

(4) Antenna inside the magazine room

In practice, wireless communication between the magazine and the gun is fraught with numerous challenges that known systems do not recognize and cannot address. For example, most wireless technologies are power hungry. The power requires bulky batteries, and therefore, power hungry wireless systems result in bulky guns that are somewhat disadvantageous for field use. Although there are known low-power wireless protocols such as Near Field Communication (NFC), these protocols only operate over very short distances and the signals generally have difficulty passing through anything other than air (e.g., passing through the components of a gun would result in errors in data transmission). Furthermore, because a gun is a high tolerance device and is designed to fit into the smallest available space, additional space for inserting or configuring antennas on a gun is severely limited. However, the inventors discovered that there are two unused areas of a gun that are in close proximity, so that no metal components are needed between them, which proves to be an ideal location for two inter-connected planar NFC antennas. That is, in the front portion of the magazine where one of the magazines tapers, there is space in the polymer magazine that can be cut to fit a planar NFC antenna without compromising the structural integrity of the magazine. There is also a recess in the left side of an AR-15 magazine chamber that does not touch the magazine and is just deep enough (e.g., Depth: 0.0175+/-0.0075 inches (0.44+/-0.19 mm), Width: 1.77 inches (45 mm), Height: 2 inches (50.8 mm)) to fit a thin (e.g., Thickness: 0.010 inches (0.25 mm), Height: 1.6 inches (40.64 mm), W: 1.050 inches (26.67 mm)) planar NFC antenna without interfering with magazine insertion and removal. In some cases, the NFC antenna may be a microstrip patch antenna fabricated on a dielectric substrate such as ROGERS RT/DUROID or RO3000 or DiClad series composite/laminate materials, gallium arsenide (GaAs), GaN, epoxy, or any other composite or substrate used in high frequency applications.

Even after the inventors discovered a solution to get a low-power wireless system into the magazine well avoiding metal interference between the antennas, this solution created a new problem: how to provide wired access between the antennas inside the magazine well to a display on the outside of the receiver. Again, the high tolerances of a gun did not leave much, if any, room to run wiring between these two components. Unexpectedly, the substrate of the planar NFC antenna is flexible, and the inventors recognized that a portion of the NFC circuit board can be bent around a bottom of the magazine compartment and then adhered to an exterior of the magazine compartment (see, e.g., FIG. 14, FIG. 16A-16C, and FIG. 17), where a connection to an RF cable can be made to thereby avoid having to drill/machine any openings in the receiver to provide a routing path for a conventional cable.

In some embodiments, an antenna may be disposed within a slightly thicker dimension of the magazine chamber, such as greater than 2 mm but less than 6 mm or less than 10 mm. In some cases, an antenna may be embedded into a wall of the magazine chamber, such as a front wall of the magazine chamber near the trigger guard. In some examples, an antenna may be built into a portion of the trigger guard adjacent to the magazine chamber or partially built into the trigger guard and partially extend into the magazine chamber within tolerances.

(5) Processor in the magazine

Another challenge of placing the sensor in the magazine is minimizing the bandwidth requirements of the wireless connection. Prior art uses a processor in or on the gun (e.g., the receiver) to process the raw data signals from one or more sensors. If this same technology is applied to the inventors' Hall Effect switch method, more than thirty separate data streams will be wirelessly transmitted over the NFC connection. To avoid this burden on the NFC connection, the inventors discovered that placing a processor on the magazine to process the Hall Effect switch signals allows a single indication of the ammunition count to be transmitted across the NFC connection, thereby greatly reducing the processing requirements of the NFC connection.

(6) Wireless power transmission to magazine

Reducing cost and weight means minimizing the number of batteries required for a round counting system. Fewer batteries not only reduce cost and complexity, but also reduce logistics and maintenance concerns. Prior art systems include a battery on the gun, but it is not typically used to power any components on the magazine. When a magazine draws power, the prior art uses a second on-magazine battery. The inventors have achieved a system that has a single battery but is also able to provide power to the magazine. Specifically, the NFC connection can unexpectedly transfer both data and power to allow the magazine to upload round count data to the gun while simultaneously transferring power back to the magazine in the opposite direction.

As can be seen, an effective round counting system for a gun with a magazine that can be inserted into a magazine chamber (such as an AR-15 and most semi-automatic long guns) is a complex challenge that requires more than just design choices. A holistic approach that overcomes a number of challenges is required. Each invention discovery usually leads to a new challenge to be solved, and an inventive balance of various interests must be found to achieve a system-level solution. The industry has sought an effective, reliable, and accurate solution for round counting for over 30 years with little progress (e.g., U.S. Patent No. 5,303,495 from 1992 used a sensor for each cartridge). Although this challenge has existed for decades, no one has come up with a solution as simple, low power, lightweight, accurate, and reliable as the solution disclosed herein.

Alternative Example

In some cases, a reed switch may be a viable alternative to a Hall effect switch. Like a Hall effect switch, a reed switch may be an example of an electrical switch that uses an applied magnetic field to operate. Reed switches may come in two main variations: normally open and normally closed switches. A normally open reed switch may disconnect or cut off under the influence of a magnetic field, while a normally closed (or closed) reed switch (such as those found in flip phones or laptops) may begin to flow current in a magnetic field. In some cases, a normally closed reed switch may be implemented in an ammunition counting system. For example, a normally closed reed switch is activated when a magnet on a bullet tray is adjacent to the reed switch. In such cases, a magnetic processing circuit connected to a plurality of reed switches (e.g. N/2+1) arranged along the interior of the magazine can identify which reed switch has been activated and determine the position of the ejector (and the ammunition count) from this. This embodiment will enable a low power application because the reed switches do not require external power to operate.

In some scenarios, a capacitive strip encoder may be utilized in an ammunition counting system. The capacitive strip encoder may use a high frequency reference signal to measure a capacitance change as a measurement of displacement (i.e., linear or rotational). A round count may be determined by analyzing the capacitance change as the deflector moves through the magazine. In one example, capacitive sensors (such as those found in digital calipers) may be arrayed along the interior of the magazine. In some cases, the deflector may include a circuit board, and a plurality of rectangular notches (or grids) may be engraved into a metal strip inside the magazine. In some cases, the circuit board and the grids on the metal strip may form a grid of capacitors. Additionally, as the deflector moves along the interior of the magazine, the rectangular notch can align and misalign with the circuit board to cause capacitance changes. In some cases, a processor in the magazine or gun can determine a position of the deflector within the magazine (and a round count) based on analyzing this changing capacitance.

，其中ε ₀=8.854×10^-12 F/m(空間之電容率)，k=板之間的介電材料之相對電容率(自由空間為1，空氣約為1，其他介質>1)，A=板之面積，d=板分離距離。在一些實施例中，電容可隨著托彈板之板與彈匣底板之間的距離變動而變動(即，電容隨著距 離增大而減小)，因為其他因數係恆定的。在此等情況中，一電容偵測器或另一處理器可使電容與一已知托彈板位置相關且判斷彈匣中之剩餘彈藥之一數目。 In another example, spring inductance may be used to determine a deflector position, which in turn may be used to determine an amount of ammunition remaining. For example, as the deflector moves and compresses or relaxes the spring, the spring inductance changes. A coil inductance detector or another device configured to measure an inductance may detect the spring inductance and correlate the spring inductance to a known deflector position and, therefore, an amount of ammunition remaining. Additionally or alternatively, a capacitance value may be measured to determine a deflector position. In one example, the deflector and magazine floor may each include a metal plate on their bottom and top sides, respectively. In this way, plates separated by an air gap can form a capacitor, where the air is the dielectric material. In some cases, the capacitance of a capacitor formed by two metal plates with a dielectric material between the two plates (i.e., a parallel plate capacitor) is given by:

, where ε ₀ =8.854×10 ^-12 F/m (capacitance of space), k=relative capacitance of the dielectric material between the plates (free space is 1, air is approximately 1, other media > 1), A=area of the plates, d=distance separating the plates. In some embodiments, the capacitance may vary as the distance between the deflector plate and the magazine floor varies (i.e., capacitance decreases as distance increases) because the other factors are constant. In such cases, a capacitance detector or another processor can correlate the capacitance to a known deflector position and determine a number of rounds remaining in the magazine.

In some scenarios, radio frequency identification (RFID) tags may be utilized in an ammunition counting system. For example, an RFID tag may be placed on a deflector to accurately determine its position within a magazine. In some instances, an RFID reader may be placed on the weapon (e.g., on the magazine chamber, trigger guard, or elsewhere on the receiver), and the position of the deflector may be determined based on a time delay in the signal received from the RFID tag. In some other cases, a unique RFID tag may be embedded in each ammunition in a magazine (e.g., attached to or within each cartridge), and the magazine ammunition counting system may determine the amount of ammunition consumed (or remaining) based on the RFID reader scanning the ammunition remaining in the magazine. Therefore, the RFID reader can also be used to identify the empty state of the magazine when there is no RFID tag recognition.

In some embodiments, processing may be performed on the side of the gun, the side of the magazine, or the gap between the magazine side and the side of the gun. For example, a processor on the side of the gun (referred to herein as a "gun processor") or a processor on the side of the magazine (referred to herein as a "magazine processor") may be configured to receive an indication of a capacitance of a parallel plate capacitor similar to the parallel plate capacitor described above. The gun and/or magazine processor may use this single capacitance reading to first determine a distance between the catapult and the bottom plate of the magazine, based on which the gun and/or magazine processor may determine a number of rounds left in the magazine. Similarly, the gun and/or magazine processor may receive a single inductance reading of a spring coupling the deflector to the base plate of the magazine. The processor may determine a distance between the deflector and the base plate and a round count in the magazine based on the inductance. In other cases, the gun and/or magazine processor may identify active magnetic or Hall effect switches (i.e., switches that output a positive or high signal based on the magnetic field strength at the switch exceeding a magnetic field threshold) to determine a deflector position within the magazine. The deflector position may then be used to determine a round count or the number of rounds left in the magazine.

102: Guns

104: Magazine

106: Bulletproof plate

108:Magnet

110: Compression spring

112: Magnetic sensor

114: Bulletproof plate seat

115: Fork teeth

116: Processing circuit system/processor

118: Transmitter

120: Receiver

122: Display device

202:Digital converter

204: Digital comparator

206: Reference signal

304: Analog comparator

306: Reference signal

404: Switch

502: Magazine

504: Magnetic sensor/switch

506: Circuit system

508: Cartridge

510: Circuit board

512: Base plate

514: Near Field Communication (NFC) Antenna

600: Ammunition counting system based on magnetic sensor

602: Magazine

604: Weapon systems/weapons

606: Magnetic switch

608:Processor

610: NFC chip

612: NFC antenna

614:NFC antenna

616: NFC chip

618: Second processor

620: Display

622: Radio Frequency (RF) Radio

624:RF antenna

700: Media Access Controller (MAC)

702: User interface

704: Serial communication

706: Board/Microcontroller Unit (MCU)

706-a: Firmware

706-b:Driver

706-c:MCU

708: Digital input/output (I/O) streaming

710:Sensor

800:Sequence diagram

801: Initialization

802: Not in sleep mode

803: Read and process output from magazine sensor

804: Convert ammunition count data into ammunition count indication

805:Ammunition count

806: Switch to low power/sleep mode

900: Ammunition counting system

901: First reference point

902: Second reference point

903: Third reference point

904: Fourth reference point

905: Compression spring

906: Coil inductance detector/detection circuit system

1000: Ammunition counting system

1001-a:NFC inductive coupling antenna

1001-b:NFC inductive coupling antenna

1002: Sensing circuit system

1003: Weapon system circuit system

1100: Block diagram

1112: Display part

1120: Non-volatile memory

1122: Bus

1124: Random Access Memory (RAM)

1126: Processing section

1127: Field Programmable Gate Array (FPGA)

1128: Transceiver assembly

1130: Input component

1132: Output part

1200: Guns

1201: Sensor/switch array

1202: Magazine antenna

1300:Details

1400:Isometric cross-section

1401:Trigger assembly

1402: Magazine room

1403:NFC antenna

1404: Depression

1500:RF cable

1600-a:NFC circuit board

1600-b:NFC circuit board

1600-c:NFC circuit board

1601: Flexible lower part

1700:Details

1800:Magnetic position sensing

1805: Hall Effect Switch

1805-a: Sensor/Switch

1805-b: Switch

1805-c: switch

1805-d: Second sensor/switch

1810:Magnet

1815: Catapult

1900: Magnetic position sensing

1905: Hall effect sensor/switch

1905-a: First sensor/switch

1905-b: Second sensor/switch

1905-c: Third sensor/switch

1910:Magnet

1915: Bulletproof plate

2000:Magnetic position sensing

2005: Hall Effect Switch

2005-a: Switch

2005-b: Switch

2005-c: Switch

2010: Magnets

2015: Catapult

2101:Show shell

2201:Ammunition count

2202: Ammunition fired since last reset

2203: Fuel meter ammunition count indicator

2300: Wireless mesh network communication system

2301: Magazine

2302: Magazine sensing circuit system

2303:Weapon System

2304: Wireless Mesh Network

2305: Wireless Mesh Network

2307: Grip

2310:Battery source

2400: Ammunition counting system

2401: Magazine

2402: High Radar Profile Object

2403: Notch

2410:Retractor

2412: Magazine room

2420: Guns

2601: Flat antenna/NFC antenna

2702: Magnetic processing circuit

2703: Additional loop

2800:Block diagram

2801: Magazine

2802:NFC antenna/NFC antenna system

2803:Display assembly

2804:Magnet

2805: Hall Effect Switch

2806:MCU

2807:EEPROM/NFC tag

2808:Filter

2809-a:NFC antenna coil

2809-b:NFC antenna coil

2810: Connector

2811: Coaxial/RF Cable

2812:RF connector

2812-a: Plug-type RF connector

2812-b:RF connector

2813:NFC reader

2814:MCU reader

2815: Regulator

2816:Battery

2817:Accelerometer

2818: Ambient light sensor

2819:EEPROM

2820: Bluetooth module

2821:Backlight

2822: Memory in Pixel (MIP)

2823:Menu button

2824:LED controller

2825: Serial wire debug (SWD) interface

2826: External crystal oscillator/clock

2827:Battery monitor

3100:Methods

3102:Configuration

3104:Configuration

3106:Configuration

3200:Methods

3202:Installation

3204:Configuration

3206:Configuration

3208:Installation

3300:Methods

3302: Identification

3304: Judgment

3306: Obtained

3400:NFC antenna

3404: Input/output connection

3406: Difference

3500:NFC antenna

3504: Input/output connection

3506: Difference

3508: Length of curve or semicircle/segment of curve or semicircle

3600:NFC antenna

3604: Input/output connection

3700:NFC antenna

3704: Input/output connection

3706:Bending section

3708: Linear segment

3800:NFC antenna

3804: Input/output connection

3806:Bending section

3808: Linear segment

3900:NFC antenna

3902a: Loop

3902b: Secondary conductor

3904: Input/output connection

3906:Both sides

4000:NFC antenna

4002a: Conductor loop

4002b: Conductor loop

4100:Methods

4102: Block

4104: Decision block

4106: Block

4108: Block

4110: Block

4200: Flowchart

4202: Block

4204: Decision block

4206: Block

4208: Decision block

4210: Block

4212: Block

4214: Decision block

4216: Block

4218: Display magazine ammunition count

4220: Block

4222: Block

4300:Methods

4302:Installation

4304: Configuration

4306:Configuration

4308:Configuration

4400:Method

4402: Configuration

4404:Configuration

4406:Configuration

4500:Methods

4502:Assignment

4504: Identification

4506:Save

4508:Show

By referring to the following detailed description and the accompanying patent claims in conjunction with the accompanying drawings, the various objects and advantages of the present invention can be understood and more easily appreciated, as well as a more complete understanding.

FIG1 is a side view of a gun receiver and a detachable magazine, illustrating an embodiment of an ammunition counting system based on a magnetic sensor.

Figures 2A and 2B are high-level circuit diagrams of a magnetic sensor-based ammunition counting system, showing the Hall effect sensor, analog-to-digital converter (ADC), comparator, and magnetic processing circuit system.

Figures 3A and 3B are high-level circuit diagrams of a magnetic sensor-based ammunition counting system, showing the Hall effect switch, comparator, and magnetic processing circuit system.

FIG. 4A shows a processor receiving signals from a Hall effect switch, wherein each cartridge position has a Hall effect switch; FIG. 4B shows a processor receiving signals from a Hall effect switch, wherein every two cartridge positions have a Hall effect switch.

FIG5 is an isometric view of the removable magazine of FIG1, showing a magnetic sensor array, circuitry for processing signals from the sensors, cartridges, a deflector, a magnet on the deflector, and an NFC antenna.

Figure 6 is a circuit diagram of an ammunition counting system based on a magnetic sensor.

FIG. 7 is a block diagram of a media access controller (MAC) of the processor in FIG. 6 according to an embodiment of the present invention.

Figure 8 is a sequence diagram of the MAC in Figure 7.

FIG. 9 is a side view of a gun receiver and a detachable magazine in which a compression spring is used as part of a counter system according to an alternative embodiment of the present invention.

FIG. 10 is a side view of a gun receiver and a detachable magazine in which an NFC interface may be used to transmit ammunition count information from a magazine to a weapon. FIG. 10 also illustrates the placement of a battery in the grip of a gun according to an alternative embodiment of the present invention.

FIG. 11 is a block diagram of a computer system according to one of the various embodiments of the present invention.

Figure 12 is a side view of the gun and detachable magazine (Figure 5), showing the area for mounting the magazine antenna and magnetic field sensing sensor.

Figure 13 is a detailed view of one of the detachable magazines in Figure 12.

FIG. 14 shows an isometric view of the trigger assembly and magazine chamber according to an embodiment of the present invention.

FIG. 15 illustrates an RF connector and cable for use with an NFC antenna and/or a weapon system display.

Figures 16A to 16C show different views of the NFC circuit board bent around the bottom of the magazine compartment.

Figure 17 is a detailed diagram of the NFC antenna and circuit board.

Figures 18, 19 and 20 show magnetic position sensing using a Hall effect sensor or switch with one, two and three magnets on the deflector, respectively.

FIG. 21 shows a display housing for mounting on a weapon according to an embodiment of the present invention.

FIG. 22 illustrates an example of a user interface in the display housing of FIG. 21 for displaying an ammunition count.

FIG. 23 illustrates an ammunition counting system that utilizes a wireless mesh network communication system to transmit information from a magazine sensing circuit system to a display on a weapon or to transmit information from a magazine sensing circuit system to/from other magazines.

FIG. 24 is a side view of a firearm receiver and a detachable magazine according to an alternative embodiment of the present invention, illustrating an ammunition counting system utilizing an ultra-high frequency or millimeter wave (mmW) transceiver.

Figure 25 is a detailed view of the magazine chamber in Figure 24, showing the notch.

Figure 26A is a front view of the magazine plate in Figure 5, showing the PCB layout.

Figure 26B is a detailed view of the magazine plate in Figure 26A.

FIG. 27A is a rear view of one of the magazine plates in FIG. 26A, showing the PCB layout.

FIG. 27B is a detailed rear view of the processing circuit of the magazine board in FIG. 27A.

Figures 28A and 28B are high-level system block diagrams according to an embodiment of the present invention.

FIG29 is a low-level system block diagram of one of the displays in FIG28A.

Figure 30 is a low-level system block diagram of the magazine in Figure 28B.

FIG. 31 is a flow chart of a method for manufacturing a magazine having an ammunition counting system.

Figure 32 is a flow chart of a method for installing an ammunition counting system on a gun.

FIG. 33 is a flow chart of a method for obtaining the number of ammunition in a magazine using an ammunition counting system having a Hall effect switch array.

FIG. 34 shows an embodiment of an NFC antenna that generally forms a loop but has several differential steps that help increase the inductive coupling and flux between the antenna and a corresponding antenna on an opposite side of the NFC interface (not shown).

FIG. 35 shows an embodiment of an NFC antenna including a plurality of differential steps on either side of a curved or semicircular length of the NFC antenna.

FIG. 36 shows an embodiment of an NFC antenna including two types of coils formed from the same conductor.

FIG. 37 shows an embodiment of an NFC antenna having two linear segments and one curved segment and two input/output connections.

FIG. 38 shows an embodiment of an NFC antenna having three linear segments parallel to each other and two curved segments connecting the three linear segments together.

FIG. 39 shows an embodiment of an NFC antenna including a loop and a secondary conductor shorting both sides of the loop.

FIG. 40 shows an embodiment of an NFC antenna including two loops configured in a generally concentric manner.

FIG. 41 illustrates a method for performing ammunition counting using an array of sensors or Hall Effect switches, a processor, and a wireless NFC interface between a magazine and a gun.

FIG. 42 illustrates a flow chart of an ammunition count display process according to one or more embodiments.

FIG. 43 illustrates a method for retrofitting a magazine using a round counting system according to one or more embodiments.

FIG. 44 illustrates a method of manufacturing a magazine having an ammunition counting system according to one or more embodiments.

FIG. 45 illustrates a method for detecting and displaying a number of cartridges remaining in one or more firearm magazines according to one or more embodiments.

Priority claim under 35 U.S.C. § 119

This patent application claims priority to U.S. Provisional Application No. 63/003,041, filed on March 31, 2020, and entitled “Determination of Round Count by Hall Switch Encoding,” and claims priority to U.S. Provisional Application No. 62/965,761, filed on January 24, 2020, and entitled “Determination of Round Count by Hall Switch Encoding.” This patent application is also a continuation-in-part of U.S. Patent Application No. 16/635,692, filed on January 31, 2020, entitled “Determination of Round Count by Hall Switch Encoding,” which is a national application under 35 U.S.C. 371 of PCT Application No. PCT/US2019/057460, filed on October 22, 2019 and published as WO2020/086598, entitled “Determination of Round Count by Hall Switch Encoding,” which claims a patent of “Determination of Round Count by Hall Switch Encoding.” Encoding" and the benefit of U.S. Provisional Application No. 62/748,602 filed on October 22, 2018. All of the above applications are assigned to the assignee of this application and are expressly incorporated herein by reference.

Although attempts have been made for decades to develop an accurate, durable, low-cost and reliable ammunition counting system for small arms (this application references an earlier application for an ammunition counting system filed as early as 1992), not all challenges have been addressed to achieve commercial success. For example, RADETEC (Rade Technology) has developed two main lines of ammunition counters: one is part of a gun grip and uses a magnet on the feeder and magnetic field sensors in the gun grip to estimate the distance of the magnet from the sensors and thereby estimate a position of the feeder and therefore the number of rounds in the magazine; the other is for long gun grips such as the AR-15, and this system again uses a magnet on the feeder but a magnetic field sensor in the magazine chamber or receiver to detect a distance between the magnet and the sensor. Both systems rely on analog magnetic field sensors that are prone to low signal-to-noise ratios and therefore erroneous readings. In addition, both of these systems also use "long range" magnetic field sensing. Magnetic field strength decreases exponentially with distance (e.g., r ² ), so even a small increase in distance has a profound effect on the field strength. By locating the magnet inside the magazine and the sensor outside the magazine (in the grip or receiver), the magnetic field is greatly reduced by the time it reaches the sensor. Also, in the case of long gun models, the magnet is even further away for a fully or nearly fully loaded magazine because the sensor is only located in the magazine chamber or receiver. Furthermore, a layer of material (e.g., metal) between the magnet and the sensor can further interfere with and degrade the magnetic field detected at the sensor, and the thickness of this material is typically not consistent along one length of the magazine. For example, in long gun models, the magazine chamber does not extend along the entire length of the magazine, which means that different materials and material thicknesses are interposed between the magnet and the sensor(s) for different hitch positions. All of these factors result in a system that suffers from high and varying signal-to-noise ratios and ultimately inaccurate ammunition counts. From an ease of use standpoint, the Radetec technology also requires the user to calibrate the system prior to use, and this calibration is inconvenient.

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as better or advantageous over other embodiments.

First, it should be noted that the flowcharts and block diagrams in the following figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, some blocks in such flowcharts or block diagrams may represent a module, segment, or portion of a program code that includes one or more executable instructions for implementing (some) specified logical functions. It should also be noted that in some alternative implementations, the functions mentioned in the blocks may not occur in the order mentioned in the figures. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or blocks may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block of the block diagram and/or flowchart and combinations of blocks in the block diagram and/or flowchart may be implemented by a dedicated hardware-based system that performs a specified function or action or a combination of dedicated hardware and computer instructions.

The following explanations and detailed descriptions of various embodiments will help readers understand and appreciate the inventive concepts mentioned above.

FIG1 is a side view of a gun receiver and a detachable magazine, illustrating an embodiment of an ammunition counting system based on magnetic sensors. The gun 102 may include a magazine 104 having a deflector 106 and one or more magnets 108 or a compression spring 110 attached to the deflector 106. The magazine 104 may also include an array of magnetic sensors 112 (e.g., magnetic switches, such as Hall effect switches). The array of magnetic sensors 112 may span the entire height of the magazine 104 or a subset thereof. For example, if the magnet(s) 108 are disposed at a seat 114 of the magazine 106, the magazine may have prongs 115 that prevent the magazine seat 114 from reaching a bottom of the magazine 104 when the magazine 104 is fully loaded. The bottom of the array of magnetic sensors 112 may be approximately aligned with a location of the magnet(s) 108 or approximately at the height of the magazine seat 114 above a bottom of the magazine 104. The array of magnetic sensors 112 may extend to a top of the magazine 104 or a location below a top of the magazine 104.

When one or more magnets 108 are within a critical detection range of one or more magnetic sensors 112, the magnetic sensors 112 may generate a detection signal and provide it to a magnetic sensor processing circuit system 116. The processing circuit system may compare the signals from the magnetic sensors 112 to determine a position of the deflector 106 and convert this position into a number of remaining ammunition (or the number of consumed ammunition). The ammunition count may then be transmitted to the transmitter 118, which wirelessly transmits the ammunition count to a wireless receiver 120 and transmits the ammunition count to a display device 122. As shown, the display device 122 is a digital display attached to an exterior of a red dot scope, but this is by no means limiting. For example, the display device 122 can be disposed on the firearm (e.g., a digital display integrated into or attached to an exterior of a scope, a digital display coupled to an exterior of a firearm receiver, a digital display disposed on a visible portion of the magazine 104, etc.), but can also be disposed on a user (e.g., in a display located in glasses/goggles). The display device 122 can be part of a scope (such as a red dot scope) or an iron sight, but can also be a display separate from a sight/aiming member. Although the transmitter 118 and receiver 120 are shown separated by several inches, in other embodiments, these may be NFC interfaces and may be configured within a few millimeters of each other, such as where the transmitter is located just below the magazine compartment and the receiver 120 is located on a portion of the trigger guard closest to a bottom of the magazine compartment.

A typical magnetic sensor 112 begins detecting one or more magnets 108 at a distance, and the strength of this detection increases as the one or more magnets 108 get closer to the magnetic sensor 112. Thus, for example, when each magnetic sensor 112 generates a voltage proportional to the magnetic field generated by the one or more magnets 108, this voltage will increase as the one or more magnets 108 approach the magnetic sensor 112. When the voltage exceeds a critical value, the processing circuit system 116 can determine that the ejector plate 106 is close to the magnetic sensor 112 whose voltage exceeds the critical value.

Each magnetic sensor 112 may include an analog-to-digital converter 202 followed by a digital comparator 204, which compares the digital signal from the digital converter 202 with a reference signal 206 or a threshold value. When the digital comparator 204 finds that the signal from the digital converter 202 exceeds the reference signal 206, a detection signal may be generated and transmitted to the magnetic sensor processing circuit system 116.

FIG. 2A shows a variation in which each magnetic sensor 112 includes an analog-to-digital converter 202, a reference signal 206, and a comparator 204, wherein the output of the comparator 204 is provided to the processing circuit system 116. FIG. 2B shows an embodiment in which the output of each magnetic sensor 112 is converted to digital and then transmitted to the processing circuit system 116, and wherein the comparator 204 of the processing circuit system 116 determines whether each signal exceeds the reference signal 206.

In one embodiment, the magnetic sensor 112, the converter 202, the comparator 204, and the processor 116 may be configured on a circuit board or other substrate that is attached to an inner surface of a magazine. This may be performed during the manufacture of the magazine or during the modification of a magazine. For example, an adhesive may be applied to a back side of the substrate and the substrate may be transferred into the interior of the magazine and then pressed against a side of the magazine to secure it to the magazine via the adhesive. In one embodiment, a groove may be formed on an inner surface of the magazine, wherein the groove may be shaped and sized to allow the substrate to be attached within the groove (i.e., the groove is slightly larger and/or deeper than the substrate). In some examples, a grinder, drill, or CNC head capable of spinning about an axis perpendicular to a direction in which the tool bit is inserted into the magazine may be used to remove material laterally from an interior of the magazine to form the groove.

Alternatively, a recess may be formed on an outer surface of the magazine, and the magnetic sensor 112, converter 202, comparator 204, and processor 116 may be arranged on a circuit board or other substrate attached to a bottom of the recess. A thin cover sheet may then be applied to the circuit board to protect it. Alternatively, the circuit board may be overmolded into an outer surface of the polymer magazine (e.g., a low temperature overmolding process may be used).

In another embodiment, holes may be drilled through a magazine, wherein the holes may be spaced a distance apart from one another. In some embodiments, the magnetic sensor 112 may be secured within the holes (toward an interior of each hole). The converter 202, comparator 204, and processor 116 may be attached to the exterior of the magazine, and electrical leads may be formed between each of the sensors and the converter 202, comparator 204, and processor 116. The leads may be formed on an exterior surface of the magazine. Alternatively, a groove may be formed on an exterior of the magazine. In such cases, the converter 202, comparator 204, and processor 116 can be attached within the recesses, and a covering layer can be applied on top of the converter 202, comparator 204, and processor 116 to attach them to the magazine and protect them from damage. For example, an epoxy or polymer having a relatively low melting temperature (e.g., lower than a melting point of solder used to make electrical connections to the converter 202, comparator 204, and processor 116) can be liquefied and poured over the converter 202, comparator 204, and processor 116 to attach them to the magazine.

FIG. 3A shows a variation in which each magnetic sensor 112 may include an analog comparator 304 that compares the analog output of the magnetic sensor 112 with a reference signal 306. When the analog comparator 304 finds that the signal from the magnetic sensor 112 exceeds the reference signal 306, a detection signal may be generated and transmitted to the magnetic sensor processing circuit system 116. FIG. 3B illustrates an embodiment in which the output of each magnetic sensor 112 is transmitted to the processing circuit system 116, and in which the comparator 304 of the processing circuit system 116 determines whether each signal exceeds the reference signal 306.

In another embodiment, each magnetic sensor 112 may provide its signal to the magnetic sensor processing circuitry 116 in analog or digital form (with an analog-to-digital converter (ADC) interspersed between the sensor and the magnetic sensor processing circuitry 116). The magnetic sensor processing circuitry 116 may then process the signals and determine a position of the deflector plate 106. For example, the magnetic sensor processing circuitry 116 may be programmed or wired to determine that one of the magnetic sensors 112 with the strongest signal is closest to the deflector plate 106. The magnetic sensor processing circuitry 116 may be hardwired with data or contain data in memory that provides a position of each magnetic sensor 112.

In some examples, the reference signal 206 may be a threshold value to which the output value of the magnetic sensor 112 is compared before being passed to the magnetic sensor processing circuitry. In one embodiment, the threshold value may be slightly lower than an output value of the magnetic sensor(s) 112 when the magnet is approximately equidistant from the two sensors. For example, when a magnet is positioned between two adjacent sensors and the output voltages from the sensors are 2V and 2.1V, respectively, the reference signal 206 may be set to <2V (e.g., 1.95V). In such cases, the output reading from the farther sensor may not be passed to the processing circuitry (i.e., if <1.95 volts). In some embodiments, an operational amplifier (or op-amp) can be used as a voltage comparator. The polarity of the output circuit of an operational amplifier depends on the polarity of the difference between two input voltages (i.e., the input voltage and the reference voltage), and thus, an operational amplifier can be used as a voltage comparator.

For example, comparator 204 (or 304) may include an operational amplifier, wherein a first reference voltage (e.g., reference signal 206) is applied to an inverting input of the operational amplifier, and a voltage to be compared with the reference voltage (i.e., the output from magnetic sensor 112) is applied to the non-inverting input. In some examples, a resistor divider (i.e., for a constant reference) or a battery source, diode, or potentiometer (i.e., for a variable reference) may be used to set the input reference voltage (i.e., reference signal 206 or 306) of the comparator. The output voltage of the operational amplifier may depend on the value of the input voltage relative to the reference voltage. For example, if the input voltage is less than the reference voltage, the output voltage is negative; if it is equal to the reference voltage, the output voltage is zero; if it is greater than the reference voltage, the output voltage is positive. Therefore, based on the polarity and/or magnitude of the output voltage from the comparator or operational amplifier, only signals that exceed the reference signal 206 (306) can be filtered and passed to the circuit system 116 for further processing.

The array of magnetic sensors 112 may include one sensor for each cartridge, wherein each magnetic sensor 112 is approximately disposed at a position where one cartridge will stop. However, in other embodiments, there may be one magnetic sensor 112 for every two cartridges: when one magnetic sensor 112 generates a strong signal and two adjacent magnetic sensors 112 generate much weaker signals, the magnetic sensor processing circuit system 116 may determine that the (several) magnets 108 are closest to the magnetic sensor 112 providing the strong signal; and when two adjacent magnetic sensors 112 provide approximately the same signal, the magnetic sensor processing circuit system 116 may determine that the (several) magnets 108 are located between the two magnetic sensors 112. This configuration can reduce the number of magnetic sensors 112 and thus reduce the complexity and cost of the array of magnetic sensors 112.

In one embodiment, rather than attaching one or more different magnets 108 to the deflector 106, the deflector 106 may be made of a material that incorporates or is made of a magnetic material. For example, in some embodiments, a polymer deflector 106 may be utilized that has magnetic threads or particles incorporated into the polymer prior to molding and/or curing. In some other cases, the magnetic sensor 112 may be positioned on the deflector and the magnet(s) 108 may be arranged along the interior of the magazine.

In one embodiment, the magnetic sensor 112, comparator 304, and processor 116 may be configured on a circuit board or other substrate that is attached to an inner surface of a magazine. This may be performed during the manufacture of the magazine or during the modification of a magazine. For example, an adhesive may be applied to a back side of the substrate and the substrate may be transferred into the interior of the magazine and then pressed against a side of the magazine to secure it to the magazine via the adhesive. In one embodiment, a groove that is just larger and just deeper than the substrate may be formed on an inner surface of the magazine so that the substrate may be attached to this groove. For example, a grinder, drill, or CNC head capable of spinning about an axis perpendicular to a direction in which the tool bit is inserted into the magazine may be used to remove material laterally from an interior of the magazine to form the groove.

In another embodiment, holes may be drilled through a magazine at a spacing from one another and the magnetic sensors 112 may be secured within the holes (towards the interior of each hole). The comparator and processor may be attached to the exterior of the magazine and electrical leads may be formed between each of the sensors and the comparator and processor. The leads may be formed on an exterior surface of the magazine. Alternatively, a recess may be formed on an exterior of the magazine, the comparator and processor may be attached within the recess, and a cover may be applied on top of the comparator and processor to attach them to the magazine and protect them from damage. For example, an epoxy or polymer with a relatively low melting temperature (e.g., lower than the melting point of solder used to make electrical connections to the comparator and processor) can be liquefied and poured onto the comparator and processor.

FIG. 4A illustrates a processor 116 receiving signals from a Hall Effect switch 404, where there is one Hall Effect switch 404 for each cartridge position.

FIG. 4B illustrates a processor 116 receiving signals from Hall effect switches 404, where there is one Hall effect switch 404 for every two cartridge positions and there is an additional Hall effect switch 404 (not shown), but the additional Hall effect switch 404 is not necessarily needed. Typically, there is one more measurement state than the number of cartridges, i.e., the empty magazine state. For example, for a 7-cartridge magazine, there are 7 cartridge positions plus the empty magazine tray position. Therefore, it may be desirable to have "N+1" Hall effect switches 404, where "N" is the number of cartridges in the magazine. However, in some cases, the same result may be achieved using only "N" Hall effect switches 404. For example, when no Hall effect switch 404 is activated, the processor 116 can be coded/programmed to determine that the deflector is in the empty position. Therefore, "N" or "N+1" Hall effect switches 404 can be implemented.

In both FIG. 4A and FIG. 4B , the dashed lines represent possible cartridge positions, but these are for illustration only and are by no means limiting. They are generally aligned with a lower half of each switch 404. However, in other embodiments, the cartridge position may be aligned with a middle portion, upper half, bottom, top, or even offset from the switch 404.

Although the magnet(s) 108 are shown as not being properly aligned with the magnetic sensor 112 and the Hall effect switch 404, in other embodiments, the magnet(s) 108 may be aligned with the magnetic sensor 112 and the Hall effect switch 404.

In one embodiment, the Hall Effect switch 404 and the processor 116 may be configured on a circuit board or other substrate attached to an inner surface of a magazine. This may be performed during the manufacture of the magazine or during the modification of a magazine. For example, an adhesive may be applied to a back side of the substrate and the substrate may be transferred into the interior of the magazine and then held against a side of the magazine to secure it to the magazine via the adhesive. In one embodiment, a groove may be formed on an inner surface of the magazine just larger than and just deeper than the substrate so that the substrate may be attached to the groove. For example, a grinder, drill, or CNC head capable of spinning about an axis perpendicular to a direction in which the tool head is inserted into the magazine may be used to remove material laterally from an interior of the magazine to form the groove.

In another embodiment, holes may be drilled through a magazine at a distance from each other and the switches 404 may be secured within the holes (towards an interior of each hole). The processor 116 may be attached to the exterior of the magazine and electrical leads may be formed between each of the switches 404 and the comparator 116. The leads may be formed on an exterior surface of the magazine. Alternatively, a recess may be formed on an exterior of the magazine, the processor 116 may be attached within the recess, and a cover may be applied on top of the processor 116 to attach them to the magazine and protect them from damage. For example, an epoxy or polymer having a relatively low melting temperature (e.g., lower than a melting point of a solder used to make electrical connections to the processor 116) may be liquefied and poured onto the processor 116.

FIG. 5 shows an isometric view of a magazine 502 implementing a magnetic sensor/switch 504 array, circuitry for processing signals from the magnetic sensor/switch 504 (not visible in FIG. 5 , but see, for example, the magnetic processing circuit 2702 in FIGS. 27A-27B , such as a processor), a cartridge 508, a deflector, and at least one magnet on the deflector. The magnetic sensor/switch 504 array may be disposed on an interior or exterior of the magazine 502 housing or even integrated as a layer within the housing material. The circuitry may be disposed on a circuit board 510, such as a printed circuit board (PCB), or circuit assembly that may include electrical traces from the magnetic sensor/switch 504 array. In the illustrated embodiment, the magnetic sensor/switch 504 array is disposed on the same circuit board or assembly as the circuit system, but in other embodiments, the magnetic sensor/switch 504 array may be located on one board and the circuit system may be located on a second board. Alternatively, the circuit system may be located on a circuit board or circuit assembly and the magnetic sensor/switch 504 array may not be disposed on a board (e.g., the sensors/switches and electrical traces may be integrated into or printed on the magazine 502 housing itself). In some other cases, the circuit system and magnetic sensor/switch 504 array may be located outside of the magazine, such as in a grip of the gun or any other portion of the gun. 5, the circuit system is located on a back side of the board (i.e., the side facing the page), in other embodiments, the circuit system may be located on the front side of the board (i.e., the side facing away from the page). The circuit system may provide an ammunition count signal to a wireless transmitter (e.g., an NFC chip), which may wirelessly transmit the ammunition count signal from the magazine 502 to a wireless receiver or transceiver, such as an antenna in a magazine chamber of the firearm, on a trigger guard, at a base of the magazine chamber, on an exterior of the magazine chamber, or on another portion of the firearm. The circuit system 506 may be configured to be adjacent to the array of magnetic sensors/switches 504 on a side of the magazine 502, or may be configured to be adjacent to or as part of a bottom plate 512 of the magazine 502. In one embodiment, the wireless transmitter may be configured in an upper half, an upper third, or an upper quarter of the magazine. In one embodiment, the wireless transmitter may be configured in an upper region of the magazine configured to be configured within a magazine chamber (e.g., see FIG. 12 and FIG. 16A).

+1)(例如30彈藥彈匣中之16個)。無論組態如何，一額外開關(N+1)可用於偵測空狀態，或處理演算法可用於基於N個開關或

+1個開關來識別空狀態。在一些實例中，可利用諸如霍爾效應感測器之磁場感測感測器來代替磁性開關或霍爾效應開關。 The magnetic sensor/switch 504 array may include one switch for each cartridge (e.g., 30 in a 30-ammunition magazine). The magnetic sensor/switch 504 array may include one switch for each cartridge and then one additional switch (e.g., 31 in a 30-ammunition magazine). Alternatively, the magnetic sensor/switch 504 array may include one switch for every two cartridges (e.g., 15 in a 30-ammunition magazine) or one switch for every two cartridges plus one additional switch (e.g., 31 in a 30-ammunition magazine).

+1) (e.g. 16 in a 30-ammunition magazine). Regardless of the configuration, an additional switch (N+1) may be used to detect an empty state, or a processing algorithm may be used based on the N switches or

+1 switch to identify the empty state. In some examples, a magnetic field sensing sensor such as a Hall effect sensor can be used instead of a magnetic switch or a Hall effect switch.

During manufacture of the magazine, the circuit board 510 may be attached to an inner surface of the magazine 502. For example, a groove may be formed on an inner portion of the magazine 502 and the circuit board 510 may be adhered within the groove. Next, a protective layer may be formed over the circuit board as appropriate, which is sufficiently thin or made of a material that does not significantly interfere with magnetic fields. In some embodiments, the circuit board or assembly may be overmolded with a material used to form the magazine, where, for example, the material is permeable or substantially permeable to magnetic fields. The layer of material overlying the circuit board may also be selected to be as thin as possible to thereby optimize the penetration of magnetic fields through this layer. Alternatively, a magazine may be modified to contain the circuit board 510. Again, a groove may be formed on an interior portion of the magazine 502, and the circuit board 510 may be adhered within the groove. However, in another embodiment, the circuit board 510 may be made thin enough (e.g., less than .5 mm or less than .1 mm) to be inserted into the magazine 502 without hindering the movement of the magazine's retainer and adhered to an inner surface of the magazine 502. Although the spiral NFC antenna 514 is shown as being located on the circuit board 510 within the magazine, in other embodiments, the NFC antenna 514 may be formed on or adhered to an outer surface of the magazine 502 and electrically coupled to the circuit board 510 via one or more electrical paths through the wall of the magazine 502. Although NFC antenna 514 will be described later as operating in conjunction with another NFC antenna within a cartridge compartment (e.g., FIG. 14 ), it should be understood that other NFC antenna configurations and locations may also be implemented (e.g., an NFC antenna on the exterior of a cartridge compartment or on the exterior of a receiver).

FIG6 illustrates an embodiment of a circuit diagram of a magnetic sensor based ammunition counting system 600. System 600 includes a magazine 602 and a weapon system 604. The magazine may include a bullet tray having one or more magnets, wherein the magnets travel along a straight or curved path as the number of ammunition/cartridges in the magazine changes. An array of magnetic sensors (e.g., magnetic switches 606, such as Hall effect switches) may be arranged along the path of the one or more magnets so that the one or more magnetic switches 606 closest to the one or more magnets produce a strongest signal. Each magnetic switch 606 communicates with a processor 608 (e.g., a microprocessor or microcontroller), which receives signals from the magnetic switches 606 and determines a position of the flipper based on these signals. In some cases, a microcontroller is a small integrated circuit designed to operate a specific operation in an embedded system. A typical microcontroller includes a processor, memory, and input/output (I/O) peripherals on a single chip.

The processor 608 then determines the number of rounds left in the magazine 602 based on the position of the ejector plate and transmits this data to a near field communication (NFC) chip 610. In some embodiments, the magnetic switch 606 may have a binary output. For example, the magnetic switch 606 may be configured to be activated based on a position of one or more magnets relative to the magnetic switch and a respective magnetic field at the magnetic switch 606 exceeding a magnetic field threshold. In some cases, the magnetic switch 606 may output a high signal (i.e., when the magnetic field exceeds the threshold) or a low signal (i.e., when the magnetic field is below a threshold) in the form of a digital or square wave or pulse output. The NFC chip 610 then communicates with an NFC chip 616 on the weapon 604 via NFC antennas 612 and 614. The NFC chip 616 then processes the wireless signal and transmits the resulting output to a second processor 618 on the weapon 604. The processor 618 may be configured to display the ammunition count on a display 620 and/or optionally transmit the ammunition count to an optional RF radio 622, which transmits the ammunition count to other devices (e.g., a display on the user's glasses) via an optional RF antenna 624. In some embodiments, the NFC antenna 612 in the magazine 602 may be parallel to a firing direction of the gun. In other words, the NFC antenna 612 can be arranged along one side of the magazine instead of its spine or along one side of the magazine that is wider and longer than the two ends. Additionally or alternatively, the processor 608 can also be arranged along one side of the magazine and parallel to a shooting direction.

In one embodiment, the NFC chips 610, 616 can also transfer power from the weapon 604 to the magazine 602. In other words, they can transfer data and power simultaneously and in opposite directions. Various known protocols can be used to transfer power and data via this wireless channel. For example, a battery can store power in the handle or grip of the weapon 604, and the NFC interface can transfer power from the battery (e.g., wirelessly) to the magazine 602 to power the processor 608 and, optionally, the array of magnetic switches 606. It should be noted that Hall effect switches typically use an external power source, while reed switches do not require external power.

FIG. 7 illustrates an embodiment of a block diagram of a media access controller (MAC) 700 that controls microcontroller hardware responsible for interacting with wired, optical, and/or wireless transmission media. A board 706 (e.g., a printed circuit board, embedded system board, etc.) may include hardware for a microcontroller unit (MCU) 706-c, one or more drivers 706-b, and firmware 706-a (i.e., software/program code that provides low-level control of device hardware). In some cases, the MCU hardware 706-c may communicate 704 serially with a user interface 702 of a firearm. The user interface 702 may be used to display an ammunition count in a gun magazine, the amount of ammunition consumed, the remaining battery power, etc. In some cases, the user interface may be an example of a user interface and display housing further described with reference to FIGS. 21 and 22. In one embodiment, the magazine may include a user interface 702 in the form of, for example, an LCD display that presents an ammunition count to a user. The LCD display may receive power when a value changes, but may otherwise be unpowered to allow the LCD to operate regardless of whether the magazine is coupled to the firearm. Additionally or alternatively, the user interface 702 may be configured to display the ammunition count of multiple magazines held by the firearm with or without a total transfer associated with the firearm, as will be described later in the present invention.

The MCU hardware 706-c may also receive a digital input/output (I/O) stream 708 from one or more sensors 710 positioned in the magazine of the gun. In some cases, the sensor 710 may be a Hall Effect switch, a Hall Effect sensor, a reed switch, etc. As previously described, a Hall Effect switch may provide a digital or at least a pulse or square wave output, while a Hall Effect sensor may provide an analog output and therefore require an analog-to-digital converter (ADC) (not shown), as described in FIG. 2 .

FIG8 is a sequence diagram 800 illustrating an embodiment of communication between the MCU 706 of FIG7 , a magazine ammunition sensor 710 (e.g., a magnetic field sensing sensor or a magnetic switch), and a user interface 702 (e.g., a screen/display for displaying an ammunition count). The MCU 706 may communicate serially with the user interface 702 and may receive a digital I/O stream from one or more magazine sensors 710. In some cases, the one or more magazine sensors 710 may be substantially evenly spaced from one another and may be arranged along an interior of a magazine. The MCU 706 may be exemplified by the processor 608 of FIG6 .

In 801, MCU 706 may be initialized. In some cases, initialization may be in response to turning on the ammunition count system, an accelerometer in the magazine (or gun) being triggered due to movement of the gun, or any other user action. If MCU 706 or sensor 710 is not in sleep mode in 802 (i.e., while the system is still being initialized), MCU 706 may begin reading and processing the output from magazine sensor 710 (i.e., ammunition count data) in 803. In 804, MCU 706 may convert the ammunition count data into a ammunition count indication. For example, the ammunition count data may include an indication of the number of active magnetic field sensing sensors (such as Hall effect switches or sensors, reed switches, etc.), based on which the MCU 706 can determine the position of a deflector including a magnet in the magazine and the ammunition count indication.

In 805, MCU 706 may transmit the ammunition count 805 to user interface 702. In some cases, MCU 706 may be coupled to a first planar antenna (e.g., a microstrip patch antenna or any other antenna fabricated on a PCB) and the first planar antenna may transmit the ammunition count indication to a second planar antenna on the gun (e.g., located within a magazine compartment of the gun). User interface 702 may communicate with the second planar antenna via one or more RF cables and connectors (e.g., see FIG. 15).

In some other cases, the MCU 706 may be located on the side of the gun opposite the magazine side. In such cases, the ammunition count data may be wirelessly transferred between the two antennas before being processed. In some scenarios, for example, if the battery or power supply for the ammunition counting system is located on the gun, the two antennas may also transfer power via an NFC connection. In one example, the battery may be located in the grip of the gun. Power may be pulsed across the NFC connection to save power, and a wake-up algorithm may be implemented to save power when the gun is not in use. Such an algorithm may be based on movement sensed, for example, via an accelerometer. The ammunition counter may enter a lower power mode when not in use.

After receiving the indication of the ammunition count 805, the user interface 702 may display the ammunition count to the user. At 806, if the MCU 706 does not receive any further I/O from the magazine sensor 710 (e.g., the gun is not in use or after a certain level of inactivity), the MCU 706 and/or sensor may switch to a low power/sleep mode. Unlike a reed switch, a Hall Effect switch or sensor requires external power to operate, therefore, a sleep mode may be used to save power.

FIG. 9 illustrates an alternative embodiment of an ammunition counting system 900. Here, a compression spring 905 is used as part of the counting system. As the deflector moves and compresses or relaxes the compression spring 905, the spring inductance changes. A coil inductance detector 906 in the base of the magazine or located elsewhere in the magazine can detect this inductance and correlate this to a known deflector position and therefore a number of remaining ammunition. The deflector may also include a first reference contact 901 and a second reference contact 902, and the magazine may include a third reference contact 903 and a fourth reference contact 904. These contacts can be used to calibrate the sensing. For example, when the first contact 901 and the third contact 903 are in contact, the system can know that the deflector is in a full height position, that is, there is no ammunition in the magazine. When the second contact 902 and the fourth contact 904 are in contact, the system can know that the deflector is in a minimum height position, that is, fully loaded. In another embodiment, the first reference contact 901 and the second reference contact 902 can be a single contact or a portion or all of the deflector can be electrically conductive and thereby operate as a contact.

In one embodiment, the limits of inductance can be tracked to self-calibrate the unit when unloaded, the compression spring 905 will be longest and have the maximum inductance. When fully loaded, the compression spring 905 will be shortest and have the minimum inductance. In this way, the detection circuit system can "adapt" and learn the full load/no load limits and infer the intermediate values between the full load extremes and the no load extremes.

In one embodiment, a spiral may be inserted into or fabricated into or attached to the main support compression spring 905. This spiral may be coupled to one of the tops of the main support compression spring 905 and thereby create a return loop to enhance the inductance measurement. In one embodiment, the detection circuit system 906 may inject current into the compression spring 905 or the loop to enhance the inductance that can be measured. The spiral may be wound in the same direction as the compression spring 905 so that it will also contribute to the inductance measurement to thereby make the measurement more sensitive.

In another embodiment, a multi-layer spring (e.g., conductor-insulator-conductor) could be used that integrates the return function into the main spring itself. The two conductor layers would be electrically connected at the top near the deflector, but electrically isolated during the travel from the top to the bottom of the magazine.

In some other cases, the compression spring 905 may be coated with an insulator (e.g., an oxide layer) to prevent the conductive parts of the spring from touching each other when compressed. In some instances, such a system needs to be calibrated for different ammunition sizes and weights because the compression and inductance of the spring may vary.

FIG. 10 illustrates an ammunition counting system 1000 in which an NFC interface is used to transmit information from a magazine sensing circuit system to a weapon (e.g., a display on the weapon) or a more powerful wireless transmitter on the weapon (which can transmit the ammunition count to a receiver/display on a user or other remote entity). In some cases, the NFC interface may include two NFC inductively coupled antennas 1001-a and 1001-b. As shown in the figure, the NFC interface can be configured at the bottom of the magazine chamber and near the trigger guard. One half of the interface can be attached to the weapon (e.g., any side of the trigger guard) and the other half can be integrated into each magazine for use with the weapon. In this way, each magazine can transmit ammunition count information to the weapon. The NFC interface can also be coupled to a power source on the weapon (e.g., a battery or weapon system circuitry 1003), and the interface can wirelessly transfer power from the weapon to the magazine and its sensing circuitry 1002. The trigger guard side of the interface can be attached to or integrated with the trigger guard. Additionally, the trigger guard can then provide a wiring path from this side of the NFC interface (i.e., the trigger guard side) to a processor and/or battery (e.g., weapon system circuitry 1003) in the grip or buttstock.

In one embodiment, an NFC chip may have a unique ID (e.g., a 64-bit ID or a 128-bit ID). This ID gives each magazine a unique identification or serial number, which can be used for tracking and inventory and other purposes. Alternatively, a serial number may be encoded or hardwired into a processor or microcontroller. Alternatively, a serial number may be distributed between the processor and the NFC chip. In other cases, a first substantially planar antenna (i.e., NFC antenna) of a magazine may be assigned a unique ID, and a second substantially planar antenna (i.e., NFC antenna) on an interior of a magazine chamber of a gun, for example, may be configured to read the unique ID associated with the first substantially planar antenna after the magazine is inserted into the magazine chamber of the gun. In some embodiments, the gun processor and optionally the magazine processor may be configured to store the unique ID and ammunition count of the magazine after the magazine is inserted into the magazine chamber. In this manner, the gun processor may be configured to cache each magazine after it is inserted into the magazine chamber and store both the ammunition count indication and the unique identifier for multiple magazines. In some cases, the ammunition count indication for any magazine previously inserted into the magazine chamber or cached by the processor may be displayed via a user interface of the gun.

In some embodiments, for example, a gun or magazine processor may be configured to display a warning on a gun display when a total ammunition count of a plurality of magazines falls below a threshold value. In some instances, an ammunition counting system may be configured to display a most recently recorded magazine ammunition count for each of a plurality of magazines in a gun to thereby provide a user with a reload, even for magazines that are not currently in the gun.

In some scenarios, eddy currents may be induced in a conductor (e.g., NFC antenna 1001-a) due to the motion of a magnet on the cartridge relative to NFC antenna 1001-a. In some embodiments, the eddy currents may also be used to power the NFC connection and processing of these signals may occur on the weapon. Alternatively, the eddy current signals may be processed on the magazine and transmitted to the weapon via the NFC connection.

Although the present invention generally refers to a substantially planar antenna, in some embodiments, other antenna shapes may be used. For example, the magazine may include a substantially planar antenna, while the firearm (e.g., the magazine chamber) includes a non-planar antenna, such as a coil antenna (e.g., the TC0502HF NFC SMD antenna manufactured by PREMO) wound around a longitudinal axis. This antenna may have dimensions on the order of a few millimeters on each axis (e.g., less than 6 mm on each side) and a capacitance of 10 pF to 100 pF. The magazine side antenna may also have different locations, such as embedded in the trigger guard or extending from the trigger guard or embedded in the magazine over-insertion stop or extending from the magazine over-insertion stop portion. In other words, the magazine-side antenna can be placed on the spine of the magazine instead of on one side of the magazine.

The methods described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in processor executable code encoded in a non-transitory tangible processor readable storage medium, or in a combination of the two. For example, referring to FIG. 11 , a block diagram 1100 is shown depicting physical components that may be used to implement an ammunition counter (and generally the processor 116 or the Hall switch encoding circuit system 116 or the processor in FIG. 33 ) according to an exemplary embodiment. As shown in the figure, in this embodiment, a display portion 1112 and non-volatile memory 1120 are coupled to a bus 1122, which is also coupled to random access memory ("RAM") 1124, a processing portion (which includes N processing components) 1126, an optional field programmable gate array (FPGA) 1127, and a transceiver component 1128 including N transceivers. Although the components depicted in Figure 11 represent physical components, Figure 11 is not intended to be a detailed hardware diagram; therefore, many of the components depicted in Figure 11 can be implemented by common construction or distributed between additional physical components. In addition, it is considered that other existing and yet-to-be-developed physical components and architectures can be used to implement the functional components described in reference figure 11.

This display portion 1112 (e.g., the pixel embedded memory (MIP) 2822 in Figures 21 and 22, Figures 28A-28B) generally operates to provide a user interface to a user, and in some embodiments, the display is implemented by an oscilloscope of a gun, an LCD/LED display mounted to a gun, a pair of goggles or glasses worn by a user of the gun, electronic paper (e.g., electronic ink) attached to a weapon or user, and a touch screen display. In general, non-volatile memory 1120 is a non-transitory memory used to store (e.g., persistent storage) data and processor executable code (which includes executable code associated with implementing the methods described herein). For example, in some embodiments, non-volatile memory 1120 includes boot loader code, operating system code, file system code, and non-transitory processor executable code to facilitate the processing of signals from a magnetic sensor as further described herein (e.g., FIGS. 31-33 and/or FIGS. 41-45 ).

In many embodiments, non-volatile memory 1120 is implemented by flash memory (e.g., NAND or ONENAND memory), but it is contemplated that other memory types may also be utilized. Although code from non-volatile memory 1120 may be executed, the executable code in non-volatile memory is typically loaded into RAM 1124 and executed by one or more of the N processing components in processing portion 1126.

The N processing components generally operate in conjunction with the RAM 1124 to execute instructions stored in the non-volatile memory 1120 to be able to process the signal from the magnetic sensor, for example, to determine the number of rounds remaining in the magazine. For example, non-transitory processor executable code for distinguishing the position of the deflector between or aligned with one of the Hall effect switches (where one switch is used for every two positions (see FIG. 4B )) can be persistently stored in the non-volatile memory 1120 and executed by the N processing components in conjunction with the RAM 1124. It will be appreciated by those skilled in the art that the processing portion 1126 may include a video processor, a digital signal processor (DSP), a microcontroller, a graphics processing unit (GPU), or other hardware processing components or a combination of hardware and software processing components (e.g., an FPGA or an FPGA including a digital logic processing portion). In some embodiments, the association between various Hall effect switch signals or signal pairs and the deflector/magnet position (and therefore the ammunition count) may be stored in the non-volatile memory 1120, such as in a lookup table.

Additionally or alternatively, the processing portion 1126 can be configured to implement one or more aspects of the methods described herein (e.g., determining an ammunition count based on a position of one or more magnets on the deflector sensed by one or more of the magnetic sensors/switches 112, 404, 504, etc., or as seen in FIGS. 31-33 and/or 41-45). For example, non-transitory processor-readable instructions can be stored in the non-volatile memory 1120 or RAM 1124 and, when executed on the processing portion 1126, cause the processing portion 1126 to identify a position of the deflector within the magazine (e.g., FIGS. 31-33 and/or 41-45). Alternatively, non-transitory FPGA configuration instructions may be persistently stored in non-volatile memory 1120 and accessed by processing portion 1126 (e.g., during startup) to configure the hardware configurable portion of processing portion 1126 to implement the functionality of Hall switch encoding circuitry 116 (or a processor for determining ammunition counts based on Hall effect switch signals).

The input assembly 1130 operates to receive signals (e.g., outputs or voltages from magnetic sensors/switches 112, 404, 504, etc.) indicating one or more aspects of the position of the deflector and thus the ammunition count. The input assembly 1130 may also receive signals sent from the magazine's circuitry/processor 116 from the NFC interface. The signals received at the input assembly may include, for example, a voltage from a Hall Effect switch indicating switch active or voltages from two Hall Effect switches indicating switch pair active. The signals received at the input assembly may include, for example, analog or digital signals from magnetic sensors/switches 112, 404, 504, etc. The output assembly generally operates to provide one or more analog or digital signals to implement an operating mode of the magazine transmitting ammunition count information to the weapon. For example, the output portion 1132 can provide the ammunition count described in the above reference figure. The depicted transceiver assembly 1128 includes N transceiver chains, which can be used to communicate with external devices via a wireless or wired network. Each of the N transceiver chains can represent a transceiver associated with a communication scheme (such as Wi-Fi, Ethernet, Profibus, NFC, etc.). The transceiver assembly 1128 can be an NFC assembly and can be configured to send and receive data and power simultaneously. The transceiver assembly 1128 may also be a more powerful second transceiver mounted on the weapon, such that the NFC transfers data from the magazine to the second transceiver, which then uses a more powerful radio transmitter to transmit the ammunition count to a receiver/display remote from the weapon (e.g., on a user or a user's goggles/glasses). As another example, the output portion 1132 may provide a voltage indicative of the ammunition count from the processor to a display.

FIG. 12 shows a side view of a gun 1200 having a sensor/switch array 1201 and a magazine antenna 1202 within or coupled to the magazine. In some cases, the magazine antenna 1202 may be an example of an NFC antenna. In addition, the magazine antenna 1202 and optionally a magazine processor (not shown) may be disposed on a side of the magazine parallel to a firing direction of the gun. A second antenna (not shown) on the gun 1200 may have an area that is substantially aligned with and/or overlaps an area of the antenna 1202 (see, for example, FIGS. 16A-16C ). FIG. 12 also shows an alternative shape for the antenna 1202 compared to the shape of the antenna shown in FIG. 5 . FIG. 13 illustrates a detailed view 1300 of the sensor array 1201 and magazine antenna 1202 of FIG. 12 . Although the magazine antenna 1202 is shown as having an L-shape, in other embodiments, other shapes of the magazine antenna 1202 may be implemented. The magazine antenna 1202 also encompasses an area that can be considered to have a height and a width. The antenna may be substantially planar so that it can be mounted within a magazine without modifying the functional dimensions of the magazine interior or magazine exterior.

FIG. 14 is an isometric cross-sectional view 1400 of a trigger assembly 1401 and magazine chamber 1402 illustrating an embodiment of the present invention. As shown in the figure, an NFC antenna 1403 (e.g., a planar NFC antenna) can be disposed in a recess 1404 in the magazine chamber 1402. As described above with reference to FIG. 10, one half of the NFC interface (i.e., NFC antenna 1403) can be attached to the weapon and the other half (i.e., a second NFC antenna, not shown) can be integrated into each magazine for use with the weapon. In this manner, each magazine can wirelessly transmit ammunition count information to the weapon. As previously described, in some cases, each magazine may be identified when inserted into a magazine chamber of a firearm (e.g., using a unique identifier to cache (if not previously cached) or based on a previously assigned unique identifier). Additionally, the magazine or gun processor may determine an ammunition count when a magazine is initially inserted into a firearm and may store the ammunition count to memory along with the associated magazine ID. In this manner, the firearm or magazine processor may be configured to track ammunition counts for multiple magazines used by a user of the firearm. In some embodiments, a gun or magazine processor may be configured to display a warning on a gun display, for example, when the total ammunition in a plurality of magazines falls below a critical value. In some instances, an ammunition counting system may be configured to display a most recently recorded magazine ammunition count for one or more magazines in the gun, including even a display of ammunition in magazines not currently inserted in the gun. In some embodiments, the NFC interface may also be coupled to a power source on the weapon (e.g., a battery or weapon system circuitry), and this interface may wirelessly transfer power from the weapon to the magazine and magazine sensing circuitry.

Wired access may be provided between the antenna 1403 inside the magazine compartment 1402 to a display on the exterior of the receiver. In such cases, the NFC antenna 1403 and its circuit board or circuit assembly may be fabricated on a flexible substrate or a substrate having a flexible portion. In one example, a portion of the NFC circuit board or assembly may be flexed around a bottom of the magazine compartment 1402 and then attached (e.g., adhered) to an exterior of the magazine compartment, as further described with reference to FIGS. 16A-16C . This portion of the NFC circuit board on the exterior of the magazine compartment 1402 may then be coupled to an RF cable (see FIG. 15 ) also disposed on the exterior of the magazine compartment 1402. This design does not require any modifications to the receiver (e.g., drilling/machining openings) to provide a routing path for a conventional cable or flex circuit. In an alternative embodiment, a wiring connection can be made through a magazine release switch (e.g., through a magazine release switch with a routing aperture). It should be noted that FIG. 14 shows only one embodiment of antenna 1403, and other shapes and locations of antenna 1403 may also be implemented without departing from the scope or spirit of the present invention. In one example, the gun NFC antenna 1403 may be disposed on a bottom surface of the magazine chamber 1402 such that it is concentrically disposed around an NFC antenna on the magazine (e.g., the magazine NFC antenna is circumferentially disposed around an upper portion of the magazine such that it is substantially aligned with the gun NFC antenna). In another example, the magazine NFC antenna may be mounted on an outer surface of the magazine, and the NFC antenna may be disposed on an inner portion of the magazine chamber. In this case, the coil of the magazine chamber NFC antenna may be curled or wound around an inner surface of the magazine chamber such that it is substantially aligned with the coil of the magazine NFC antenna that is coiled or wound around an outer surface of the magazine. In other words, the coil of the magazine chamber NFC antenna may be wound within the inner periphery of the magazine chamber. In some aspects, for example, if both antennas are projected onto the same plane, the coil of the magazine chamber NFC antenna may appear to surround the coil of the magazine NFC antenna. In an alternative, the magazine NFC antenna may be disposed on an outer surface of the magazine, a circuit board including a processor and/or magnetic or Hall effect switches may be disposed within the magazine, and a via or other conductive aperture in the magazine chamber may enable an electrical connection between these internal and external components of the magazine. Alternatively, a planar flex circuit may be utilized that is configured to, for example, descend from the circuit board and wrap around a bottom edge of the magazine and turn upward to reach the antenna along the outer surface of the magazine. In another configuration, a first coil antenna (such as an NFC antenna) may be mounted at or near a flange on the magazine, wherein the first coil antenna or flange may be roughly aligned with another coil antenna on the magazine compartment. Another embodiment may see a magazine compartment funnel or similar addition to the bottom of the magazine compartment having a thickness sufficient to accommodate the NFC antenna on the side of the gun. In some embodiments, the antenna 1403 may be adhered to the magazine compartment 1402 during the manufacture of the gun or in a modification process.

Although FIG. 14 shows an antenna 1403 on a flexible substrate shaped to fit within a recess 1404 characteristic of an AR-style magazine chamber, if the antenna 1403 is used in a different housing, the antenna 1403 and the flexible substrate may be shaped and sized to fit within the unique features of another magazine chamber. Specifically, the flexible substrate may be shaped and sized to fit tightly within a unique feature of a magazine chamber of another housing that may or may not include a recess, such as recess 1404. For example, when a firearm has a wider recess 1404, the flexible substrate may be formed to fit tightly within the wider recess 1404. The antenna 1403 may or may not be enlarged. Furthermore, because antenna 1403 can be installed in a factory or by a user using uncomplicated and imprecise tools and components, the flexible substrate can be sized to fit snugly within a recess or other feature of a magazine compartment, and this snug fit can make it easier for a worker or home user to align antenna 1403 with a desired location (i.e., with an antenna in a magazine). In some cases, antenna 1403 and flexible substrates can be manufactured to fit with a variety of types, sizes, and shapes of magazine compartments, where different magazine compartments can have different recesses or other structural features, thereby each requiring a different flexible substrate shape and size. For such a universal antenna kit, one antenna 1403 may be used, but the flexible substrate may include lines, perforations, etc., which may be used to mark the outlines on the flexible substrate for different mounts. When a user needs to modify the flexible substrate to fit a different magazine compartment, the user may cut along the lines or perforations and separate the "discarded" flexible substrate to form a flexible substrate that fits tightly within a different magazine compartment. Alternatively, the perforations may allow a user to pull out additional flexible substrates.

When a polymer or other non-metallic magazine compartment is used, a side of the NFC interface (i.e., a side of the NFC antenna) can be disposed on an exterior of the magazine compartment. To date, the side of the NFC antenna has been described as being disposed inside the magazine compartment, in large part because the metal magazine compartment blocks wireless signals from the magazine to an exterior of the magazine compartment. However, when the magazine compartment does not interfere with wireless signals (e.g., when the magazine compartment is non-metallic or transparent to wireless signals), the NFC signals can be passed directly to an external antenna to thereby avoid the compromises and design challenges of placing a side of the NFC interface inside the magazine compartment and then having to route data and power to an exterior of the magazine compartment.

FIG. 15 illustrates an example of an RF cable 1500 for connecting an antenna 1403 to a display mounted on a weapon. In some cases, the RF cable 1500 is detachable, which can be used to provide strain relief on the antenna attachment. Additionally or alternatively, the detachable cable 1500 can also include a connector with strain relief for attaching to a display. In some examples, connectors can be attached to both the antenna and the display and connected via an RF cable.

Figures 16A, 16B and 16C respectively show different views of NFC circuit boards 1600-a, 1600-b and 1600-c that are flexed around the bottom of the magazine chamber (e.g., the flexible lower portion 1601) and then attached (e.g., adhered) to an exterior of the magazine chamber (where a connection to an RF cable (e.g., RF cable 1500 in Figure 15) can be made). Figure 17 shows a detailed view 1700 of an NFC antenna 1403 including the flexible lower portion 1601 of the circuit board that can wrap around the bottom of the magazine chamber. As described with reference to FIG. 14 , the left side of an AR-15 magazine chamber may include a recess 1404 that does not contact the magazine and is just deep enough (e.g., Depth: 0.0175+/-0.0075 inches (0.44+/-0.19 mm), Width: 1.77 inches (45 mm), Height: 2 inches (50.8 mm)) to fit a thin, substantially planar NFC antenna 1403 (e.g., Thickness: 0.010 inches (0.25 mm), Height: 1.6 inches (40.64 mm), W: 1.050 inches (26.67 mm)) without interfering with magazine insertion and removal. In some examples, NFC antenna 1403 may be a microstrip patch antenna (e.g., copper or another highly conductive material) fabricated on a dielectric substrate (e.g., ROGERS RT/DUROID or RO3000 or DiClad series composite/laminated materials, gallium arsenide (GaAs), GaN, epoxy, or any other composite or substrate used in electromagnetic and high frequency applications). As shown in the figure, antenna 1403 may cover an area smaller than the main area of the circuit board. For example, when the main portion of the circuit board in FIG. 17 has a height and a width, antenna 1403 has a smaller width and a much smaller height (e.g., a height that is approximately half the height of the main portion of the circuit board).

In some other cases, the planar NFC antenna 1403 may include a highly conductive trace (e.g., copper) fabricated on a substrate or a dielectric circuit board in the shape of a coil, a circle, an ellipse, or any other continuous shape. In some embodiments, a continuous metal layer (i.e., a ground plane) may be bonded to a second side of the substrate (i.e., the side not including the antenna trace). The substrate thickness should be selected to at least ensure that the planar NFC antenna 1403 fits within the magazine compartment of the receiver. In addition, the substrate material and thickness may also be selected based on one or more antenna performance parameters such as resonant frequency, directivity, gain, return loss, bandwidth, etc. For example, a high frequency (smaller wavelength) application requires a thinner substrate than a low frequency application. In addition to the substrate material/thickness, the 2D geometry of the NFC antenna can also affect its radiation pattern, beam width, etc., and different shapes can be selected for different scenarios.

For example, FIGS. 34-40 illustrate alternative NFC antenna patterns, but these different shapes rarely affect inductive coupling, power, etc. On the other hand, the number of turns in the NFC antenna affects the inductive coupling between the two sides of the NFC interface. In some embodiments, the NFC antenna (e.g., magazine and/or gun side) may also include a second layer of coils and thus may have a three-dimensional shape. For example, the inductive coupling between the NFC antennas on the two sides of the NFC interface may be enhanced by increasing the number of coils. In some cases, the coil count of the NFC antenna may be increased radially or vertically (e.g., by adding layers to (several) NFC antennas), which may be used to increase the inductance and enhance the coupling between the NFC antennas. Similarly, two NFC antennas may be configured on the magazine (one on each side of the magazine) but routed in parallel so that they transmit the same signal to the NFC-connected side of the gun. This doubling of antennas sending the same signal may increase inductance and thus allow each of the NFC antenna pairs to be smaller than an embodiment where only one NFC antenna is used on the magazine.

In some embodiments, the cartridge may include both an NFC antenna and a non-NFC antenna, so that longer distance transmissions via the non-NFC antenna may also be enabled in parallel with or in lieu of NFC transmissions. In another embodiment, a single NFC antenna may be configured to transmit via both NFC and non-NFC (e.g., see U.S. Patent No. 9,793,616, which is incorporated herein by reference).

In some embodiments, the reader side of the NFC antenna (typically the cartridge side of the interface) may include a larger antenna than the transmit side (typically the cartridge side of the interface). This size difference allows for greater tolerance in placing the two sides of the interface, as either can deviate slightly from ideal alignment while still ensuring that all or most of the smaller antenna is always aligned with some portion of the larger antenna. For example, the larger of the two antennas may be 30mm×30mm and the smaller may be 20mm×20mm. It should be noted that the larger antenna draws more power than the smaller antenna. Therefore, it is desirable to balance easy alignment with low power draw.

In other embodiments, the NFC antenna may include two different NFC coils on each of the transmit and receive sides of the interface (see, e.g., FIG. 40 ). A first of these antennas may be configured to transmit data, while a second may be configured to transmit power. Similarly, an NFC antenna formed from two separate interfaces may enhance coupling and thus data and power transfer. In this example, the two separate interfaces imply two pairs of separate inductively coupled coils, e.g., a first pair of inductively coupled coils and a second pair of also inductively coupled coils. In one embodiment, the magazine may include a first coil on a first side of the ammunition stack (e.g., a first side of the magazine parallel to the direction of fire of the gun) and a second coil on a second side of the ammunition stack (e.g., a second side of the magazine opposite the first side, wherein the second side is also parallel to the direction of fire of the gun). In addition, the magazine chamber may include a third coil on a first side of the magazine chamber aligned with and coupled to the first coil in the magazine and a fourth coil on a second side of the magazine chamber coupled to the second coil in the magazine. Alternatively, each of the two pairs of NFC antennas (e.g., two interfaces and four antennas) may be arranged at an angle (e.g., orthogonal or 90°) relative to the other pair to thereby minimize coupling between the pairs. In some scenarios, configuring NFC antenna pairs so that they are orthogonal to each other can be used to minimize the signal-to-noise ratio (SNR). Additionally or alternatively, such a configuration may also allow the two NFC antenna pairs to operate via different protocols and/or transmit different data.

FIG. 18 illustrates magnet position sensing 1800 using Hall effect switches 1805 according to an embodiment of the present invention, wherein a single magnet 1810 is positioned on a deflector plate 1815 and a number of Hall effect switches 1805 is N/2 or N/2+1. In some cases, the magazine may be arranged with magnets instead of Hall effect switches. In such cases, one or more Hall effect switches and associated electronics may be placed on the deflector plate. As shown in the figure, at the 0 position (e.g., an empty magazine), the magnet 1810 may be sensed by one sensor or switch 1805-a. Then, at the 1 position (an odd position), the magnet 1810 may be sensed by two adjacent switches 1805-b and 1805-c. It should be noted that in this example, "P" is the pitch distance that the deflector plate 1815 moves for each cartridge, and the switches 1805 are spaced two (2) pitch distances apart. Thus, at the 1 position, the magnet 1810 on the deflector plate 1815 will be approximately equidistant from the first two switches 1805-b and 1805-c. Similarly, at the 2 position (an even position), the magnet may be aligned with the second sensor or switch 1805-d because it has moved two (2) pitch distances from the 0 position. Thus, it can be seen that for a single magnet 1810 on the deflector plate 1815, the magnet 1810 is sensed by a single sensor or switch 1805 at even positions and by two adjacent switches 1805 at odd positions. Figures 19 and 20 show different implementations using two and three magnets 1910 and 2010 on deflectors 1915 and 2015, respectively. Figure 19 can also be implemented using Hall effect sensors, where the output of each sensor can be provided to a comparator so that only the sensor that sees a certain signal strength will be temporarily stored as an active sensor.

As mentioned above, unlike reed switches, Hall Effect switches require a power supply to operate. To efficiently power manage Hall switches, only the switches that actively sense a magnet need to be powered. When a magnet leaves the current active sensor, the sensor generates a digital signal (e.g., an interrupt). In these cases, because the active switches for the next state are known, the switches can only be activated until the position of the magnet on the deflector is determined. Therefore, the amount of current drawn by the switch can be minimized to extend battery life. In some scenarios, an accelerometer can be installed to wake up the ammunition counting system. For example, the accelerometer can be configured to detect movement of the deflector to allow the Hall Effect switch to be turned off when the weapon is inactive or during storage. Additionally or alternatively, the Hall switch may be turned off after a certain inactive period (e.g., 30 seconds, 60 seconds, 90 seconds, etc.), and the last active Hall sensor may be periodically (e.g., every 10 seconds, 20 seconds, 30 seconds, etc.) polled to check for a state change before resuming operation. In other cases, an accelerometer may be coupled to the deflector, wherein the accelerometer may be in electronic communication with the magazine processor. Furthermore, the accelerometer may be configured to recognize an upward "dash" movement of the deflector, which may indicate that one of the uppermost rounds in the magazine was loaded into the chamber after firing the gun. In such cases, the magazine processor may decrement the current round count by one based on the measurement from the accelerometer. In some cases, an accelerometer coupled to the deflector may only provide acceleration readings above a threshold value, which can be used to filter out false readings associated with normal movement of the gun. In some examples, data from the Hall Effect switch may be used in conjunction with other data including, but not limited to, capacitance data associated with an air gap between the deflector and the base plate, spring inductance data, and/or accelerometer data used to identify when a round count needs to be updated (e.g., decremented by 1).

FIG. 19 illustrates magnet position sensing 1900 using Hall effect sensors or switches 1905 according to an embodiment of the present invention, wherein two magnets 1910 are positioned approximately three (3) pitch distances apart on a deflector plate 1915. As shown in the figure, in the 0 position, the magnet may be sensed by the first three (3) sensors or switches 1905-a, 1905-b, and 1905-c, wherein an output from the first sensor 1905-a may have the highest magnitude and the outputs from the second sensor 1905-b and the third sensor 1905-c may have equal but smaller magnitudes. For example, at the 1 position, the first and second sensors 1905 may have an equal magnitude and the third sensor 1905 may have a larger magnitude. In this way, the processor or MCU hardware can distinguish between the 0 position and the 1 position, for example by using a comparator, even if the same number of sensors 1905 are active. Similar to Figure 18, N/2 or N/2+1 Hall effect switches can be deployed in such a setup.

FIG. 20 illustrates magnet position sensing 2000 using Hall effect switches 2005 according to one embodiment of the present invention. In this example, three magnets 2010 are positioned four (4) pitch distances apart (or between three (3) and four (4) pitch distances apart) on the deflector plate 2015. Additionally, N/3 Hall effect switches 2005 are required in this arrangement. Similar to FIGS. 18 and 19, a processor can determine the deflector plate 2015 position and subsequent round count based on analysis and comparison of the outputs from the active switches 2005. In the 0 position, switches 1, 2, and 4 (i.e., switches 2005-a, 2005-b, and 2005-c) can be active. Similarly, in the 1 position, switches 1, 3, and 4 are active. In the 2 position, switches 2, 3, and 4 are active. In this embodiment, Hall effect sensors may also be implemented. Although more complex than FIG. 19 from a magnet and processing perspective, FIG. 20 may provide a cheaper solution because fewer Hall effect switches/sensors 2005 are required (e.g., N/3 versus N/2).

In both examples of FIG. 19 and FIG. 20 , a stronger magnet may be used that is capable of triggering more switches than a weaker magnet. Thus, for example, the flipper magnet may trigger three Hall Effect switches at a time, and trigger less than three Hall Effect switches when the flipper is in other positions. This embodiment may allow for more accurate sensing of the flipper position or may allow for the use of fewer Hall Effect switches (e.g. <N/2 switches).

FIG. 21 illustrates an example of a display housing mounted on a weapon according to an embodiment of the present invention. As shown in the figure, the display housing 2101 may include a screen or a display (see FIG. 22 ) having a user interface including display graphics and control buttons. In some examples, the display housing 2101 may be used to indicate an ammunition count 2201, ammunition fired since the last reset 2202, a fuel gauge ammunition count indicator 2203 for quick reference along the side and/or top of the display, and the like. The user interface/display may also implement features such as a flashing indicator or the ability to change brightness (i.e., set by the user or automatically based on ambient light) when the ammunition count drops below a threshold value (e.g., 9 rounds or less). For example, different colored lights may be used to indicate the ammunition count or a range of ammunition remaining in a magazine. An oscilloscope (such as a red dot oscilloscope) may include one or more LEDs around its perimeter that provide an indication of the ammunition count. In another embodiment, a light ring around the oscilloscope may be used to indicate the ammunition count (e.g., via brightness, color, or number of LEDs lit). Such visual indicators may also be integrated into or overlaid onto the aiming optics (e.g., via an add-on device such as a COTI Thermal overlay). Audio and tactile feedback indicators may also be used in addition to or in lieu of light indicators.

In some cases, a user may use one or more buttons to change the display type. The user interface may also be able to communicate wirelessly (e.g., Bluetooth) with other devices (e.g., another soldier's weapon/body mounted device or a command unit). The display housing 2101 may be powered via an internal battery, and this same battery may provide power to the magazine via an NFC connection. Alternatively, the display housing 2101 may receive power from a battery stored in the stock or grip of the gun. In some embodiments, power may be provided via a powered auxiliary rail.

As previously described, in some embodiments, the display housing can be configured to indicate an ammunition count of a plurality of magazines stored by the firearm (e.g., a different ammunition count for each magazine or a combined total for all magazines). In some examples, after a magazine is inserted into a magazine compartment of the firearm, an NFC antenna in the magazine compartment can be configured to receive a unique identifier associated with the magazine, for example, from a magazine processor and/or NFC antenna in the magazine. In some cases, the unique identifier and magazine ammunition count can be stored by the firearm processor in its internal memory or another memory device electronically coupled to the firearm. In some cases, a user can view an indication of the ammunition count for multiple magazines previously used in the firearm by the same user (or other users). For example, as a non-limiting example, the display housing 2101 can display multiple ammunition counts for multiple magazines on a red dot scope display.

FIG. 23 illustrates a wireless mesh network communication system 2300 for communicating from a magazine 2301 to a weapon system 2303 (e.g., weapon system circuitry and display) or for communicating between a magazine 2301 and other devices or even other magazines (not shown). Magazine sensing circuitry 2302 may establish a wireless mesh network 2304 for magazine-to-weapon communication (e.g., for transmitting and displaying a magazine ammunition count on the weapon system 2303). In some cases, the weapon system may include at least one display housing similar to the display housing 2101 described with respect to FIGS. 21 and 22. Additionally or alternatively, the magazine sensing circuit system 2302 may establish a wireless mesh network 2305 for communicating with other magazines. In some cases, the magazine sensing circuit system 2302 may be an example of an ammunition counting system or magazine handling circuit described with reference to any figure herein.

Wireless mesh networks 2304 and/or 2305 may operate using, to name a few non-limiting examples, a threaded protocol, a Bluetooth Low Energy (BLE) protocol, or a Zigbee protocol. In some scenarios, magazine 2301 may be normally in a sleep state (i.e., to save power). In addition, if the number of ammunition in the magazine changes (increases or decreases), the magazine may wake up, send a new ammunition count and a unique magazine ID to weapon system 2303, and then return to a sleep state. In some cases, the wake-up procedure may be based in part on triggering an accelerometer in the weapon or magazine 2301. In one example, the accelerometer may be mounted on the bullet tray, but other locations may be considered in different embodiments. In some cases, accelerometers on the deflector can also be used in conjunction with other data (e.g., from magnetic or Hall effect switches) to infer an accurate ammunition count. In some cases, magazine 2301 can also report an ammunition count and unique ID to any other nearby magazines or guns on the mesh network 2305. Magazine sensing circuitry 2302 can be embedded on one side of magazine 2301 along with a battery source. Alternatively, as shown in the figure, battery source 2310 can be located in the grip 2307 of the gun. In other cases, the battery source can be located at or near or in the display or weapon system 2303. It should be noted that battery source 2310 can be rechargeable or rechargeable (i.e., primary or secondary type).

FIG. 24 illustrates an ammunition counting system 2400 utilizing an ultra-high frequency (UHF) radar or mmW transceiver (e.g., operating around 60 GHz) according to an embodiment of the present invention. In some scenarios, a mmW transceiver may transmit electromagnetic waves and analyze their reflections from objects, which may be referred to as active scanning. In some other scenarios, a mmW transceiver may only use ambient radiation and/or radiation emitted from a person or object to generate an image or detect an object, which may be referred to as passive scanning.

As shown in FIG24 , a gun 2420 may include a magazine 2401, an object 2402 having a high radar profile on a deflector 2410 mounted on the magazine 2401, and a slot 2403 in front of the magazine chamber 2412. A mmW transceiver may be used to detect the position of the deflector 2410 within the magazine 2401 by transmitting UHF waves (the slot 2403 may allow the UHF waves to pass through the magazine chamber 2412) and then detecting the reflected waves. In some cases, the deflector position (and ammunition count) may be determined based on the time required for reflection (i.e., time delay), the phase of the reflected waves, any frequency changes, etc. In other words, by analyzing the subtle changes in the reflected signal over time, the mmW transceiver and its processing circuit system can be used to accurately locate the position of the bullet tray 2410 in the magazine 2401 and thus the ammunition count.

In some cases, the mmW-based ammunition counting system 2400 requires limited modification to the magazine 2401, other than the addition of a high radar profile object 2402 on the deflector. Furthermore, no batteries are required in the magazine because the mmW transceiver is placed on the weapon and all processing of the reflected waves received at the transceiver is done. However, such a system requires minor modifications to the magazine chamber (i.e., notches 2403 in the magazine chamber 2412, also seen in FIG. 25), and the overall power requirements may be comparable to or greater than using a Hall Effect switch in the magazine, but less than an RFID tag.

FIG. 26A is a front view of the magazine 502 board in FIG. 5 , showing the PCB layout and a substantially planar antenna 2601 , such as an NFC antenna. FIG. 26B is a detailed view of the NFC antenna 2601 of the magazine 502 board in FIG. 26A .

FIG. 27A is a rear view of the magazine plate 502 in FIG. 26A, which shows a magnetic processing circuit 2702 of the magazine plate. FIG. 27B is a detailed view of the magnetic processing circuit 2702 in FIG. 27A. An example of the magnetic processing circuit 2702 is the processor 608 in FIG. 6. The magazine plate in FIGS. 26A-26B and 27A-27B can be the circuit board 510 seen in FIG. 5 or the circuit board seen in FIGS. 12 and 13 or also in FIGS. 16A-16C.

Some jurisdictions impose regulations that limit the number of ammunition a magazine can have (e.g., 10 ammunition or less, 30 ammunition or less, etc.). In such cases, separate ammunition counting systems need to be created for 10-ammunition and 30-ammunition magazines (i.e., with different numbers of Hall effect switches or sensors or reed switches). Although the number of switches or sensors needs to vary for different magazine sizes, a single PCB can accommodate both sizes. In some cases, the magnetic processing circuit 2702 may include an additional loop 2703 that can be cut off (e.g., for a smaller magazine) and retained for a larger magazine. In some other cases, the additional loop 2703 may be formed when connecting two pins on the magnetic processing circuit 2702. In such cases, the additional loop 2703 may initially remain "open" for use in a smaller magazine (i.e., the two pins remain unconnected or open) and "shorted" before being installed in a larger magazine (or vice versa). In some embodiments, the two pins may be shorted via soldering (i.e., soldering the two ends of a wire to the first pin and the second pin), or the two pins may be connected to each other using the same bus on the PCB. In this way, only a single PCB needs to be designed and produced, and additional circuits can be used to optimize the production of different types of magazines and ammunition counting systems.

The circuit board shown in Figures 26A-26B and 27A-27B can be adhered to an interior of a magazine during manufacturing or in a modification process. For example, the circuit board can be thin enough to slide into the interior of the magazine and adhere it to the inner surface of the magazine so that the circuit board does not interfere with the operation/movement of the ejector plate. Alternatively, a groove shaped to accept the circuit board can be formed on an interior of the magazine, such as by drilling or CNC milling.

Figures 28A-28B illustrate a block diagram 2800 of an embodiment of an ammunition counting system including a magazine 2801 having a magazine circuit board (also shown as magazine 502 circuit board in Figures 5, 26A-26B, and 27A-27B), a substantially planar antenna on the gun (such as an NFC antenna 2802), and a display assembly 2803.

The magazine 2801 may include one or more magnets 2804 and a deflector. The magnets may be mounted on the deflector along with an optional accelerometer. In addition, the magazine circuit or circuit board may include a number of Hall effect switches 2805 equal to the number of deflector positions (i.e., the number of ammunition) or <N Hall effect switches 2805 (e.g., N/2, N/3, N/4, N/2+1, N/3+1, or N/4+1). The circuit board or assembly may also include a processor including an MCU 2806 and an EEPROM 2807 and an NFC antenna coil 2809-a. The NFC antenna coil may be manufactured on a printed circuit board. In some examples, the EEPROM 2807 may be an integrated circuit (IC). The circuit may also include a filter 2808 and an NFC controller (such as an NFC tag 2807) as appropriate.

The NFC antenna system 2802 on the gun may include an NFC antenna coil 2809-b, whose area may substantially overlap an area of the NFC antenna coil 2809-a. The NFC antenna system 2802 may also include a connector 2810, a coaxial (or RF) cable 2811, and a plug-in RF connector 2812-a. One or more subcomponents of the NFC antenna system 2802 may be interconnected to each other via one or more buses. In some cases, one or more buses may be used to exchange both power and data.

The display assembly 2803 may include an RF connector 2812 for receiving from the NFC antenna 2802, as described with reference to FIGS. 14 and 15. The display assembly 2803 may also include an NFC reader 2813, an MCU reader 2814, a regulator 2815, a battery 2816, an accelerometer 2817 (optional), an ambient light sensor 2818 (optional), an EEPROM 2819, a Bluetooth module 2820, a backlight 2821, a display (e.g., pixel embedded memory (MIP)) 2822, and one or more menu buttons 2823. As shown in the figure, one or more subcomponents of the display assembly 2803 may be connected to the MCU reader 2814 via one or more buses. In some embodiments, a separate NFC connection may be used between the firearm and the display assembly 2803 to simplify the digital connection between the display assembly 2803 and the firearm (e.g., a wired connection is not required between the display assembly 2803 and the NFC receiver on the magazine chamber).

FIG. 29 illustrates a low-level block diagram of an embodiment of the display assembly 2803. As shown in the figure, one or more subcomponents of the display assembly 2803 can be connected to the MCU reader 2814 via one or more buses.

The display assembly 2803 may include an RF connector 2812-b for receiving from the NFC antenna system 2802 (not shown), as further described with reference to FIGS. 14 and 15. The display assembly 2803 may also include an MCU reader 2814 connected to the following: an NFC reader 2813, a regulator 2815, one or more menu buttons 2823, an LED controller 2824, an accelerometer 2817 (optional), an ambient light sensor 2818 (optional), a battery monitor 2827, an EEPROM 2819, a Bluetooth module 2820, and a display (e.g., pixel embedded memory (MIP)) 2822.

Additionally, a regulator 2815 (e.g., a 3V regulator) can be connected to a battery 2816, which can be connected to a battery monitor 2827. In some examples, an LED controller 2824 can be connected to a backlight 2821, where the backlight brightness can be adjusted based on an output from an ambient light sensor 2818. In some examples, the MCU reader 2814 can also communicate with a serial wire debug (SWD) interface 2825 to enable a tester to access system memory, peripherals, and/or debug registers. In some scenarios, the NFC reader 2813 may be connected to an external crystal oscillator or clock 2826 (e.g., operating at 27.12 MHz), which may be used to replace one of the built-in internal oscillators of the MCU reader 2814 or NFC reader 2813. In some situations, when serial communication is used or when a fast clock or accurate timing is required, the built-in oscillator is susceptible to errors, and the external clock 2826 may be used to improve accuracy.

FIG. 30 illustrates a low-level block diagram of an embodiment of magazine 2801. FIG. 30 implements one or more aspects of the diagrams described herein (including at least FIG. 28B).

Turning now to FIG. 31 , a method 3100 of manufacturing a magazine having an ammunition counting system is now described. In some cases, the magazine may include at least one overtravel stop and a deflector, wherein the deflector includes one or more magnets.

The method may include configuring 3102 magnetic field sensing sensors (e.g., <N magnetic switches or sensors) substantially along a path of one or more magnets as the deflector moves along a length of the magazine, where N is a maximum number of cartridges that can be loaded into the magazine, the sensors generating ammunition count data based on a position of the one or more magnets relative to the magnetic field sensing sensors. In some cases, magnetic switches such as Hall effect switches may be used in place of sensors.

The method may also include configuring 3104 a first substantially planar antenna on an interior portion of the magazine at or above the over-travel stop (or in a region of the magazine configured to at least partially fit within a magazine chamber of the firearm), the first substantially planar antenna configured to transmit an ammunition count indication from the magazine to a second substantially planar antenna on the firearm, the ammunition count indication being based on ammunition count data. In some examples, the second substantially planar antenna may transmit power from, for example, a power source located on the firearm (e.g., a gun grip) to the first substantially planar antenna in a direction opposite to the data flow. In this manner, magnetic processing circuitry and sensors in the magazine may receive power without requiring power in the magazine.

Additionally, the method may include configuring 3106 the first substantially planar antenna such that an area of the first substantially planar antenna defined by a height and a width is primarily aligned with an area of a second substantially planar antenna coupled to an interior of a magazine chamber of a firearm.

FIG. 32 illustrates a method 3200 of installing a round counting system on a firearm. The method may include installing 3202 a removable magazine including at least one overtravel stop and a retainer, the retainer including one or more magnets.

The method may further include configuring 3204 magnetic field sensing sensors (e.g., <N) substantially along a path of one or more magnets as the deflector moves along a length of the magazine, where N is a maximum number of cartridges that can be loaded into the magazine, the sensors generating ammunition count data based on a position of the one or more magnets relative to the magnetic field sensing sensors. Similar to FIG. 31 , in some embodiments, a magnetic switch such as a Hall effect switch may be used instead of a sensor.

In some cases, the method may include configuring 3206 a first substantially planar antenna on an interior portion of a magazine at or above an over-travel stop (or in an area of a magazine configured to at least partially fit within a magazine compartment of a firearm). The method may also include mounting 3208 a second substantially planar antenna on an interior portion of a magazine compartment of a firearm such that an area of the first substantially planar antenna is substantially aligned with an area of the second substantially planar antenna, wherein the first substantially planar antenna and the second substantially planar antenna are configured to exchange an ammunition count indication and power based on ammunition count data via a near field communication (NFC) connection.

It should be noted that methods 3100 and 3200 may be OEM or retrofit procedures.

FIG. 33 illustrates a method 3300 for obtaining the number of ammunition in a magazine using an ammunition counting system having a Hall effect switch array. The method 3300 may be implemented by one or more processors receiving computer readable instructions from one or more tangible programmable computer readable media. The processor may receive data from other parts of the system (such as from the Hall effect switch array) and provide data and instructions to other parts of the system. The system includes at least a processor on or in the magazine for evaluating data from the Hall effect switch array. In some cases, this processor may be referred to as a magazine processor. Additionally or alternatively, the processor may be located on the gun. In addition, the system at least includes an array of Hall effect switches and an electrical data connection between the switches and the processor. If located on the magazine, the magazine processor can be configured to transmit ammunition count data to a wireless interface across an air gap between the magazine and the gun. This can include an NFC interface with two opposing NFC antennas, one NFC antenna configured on or in the magazine and one NFC antenna configured on the gun (e.g., in the magazine chamber). The gun side of the NFC interface can be configured to pass the ammunition count to a second processor on the gun (i.e., a gun processor). The ammunition count can be used by this second processor in a variety of ways (e.g., sending instructions to a display or sending the ammunition count outside the gun).

In some embodiments, the number of switches deployed in method 3300 may (but not necessarily) < N. In addition, method 3300 may be implemented via an analog device within the magazine, an analog device external to the magazine (e.g., on a receiver or an oscilloscope), a digital device within the magazine, a digital device external to the magazine (e.g., on a receiver or an oscilloscope), or a combination of analog and digital devices. For example, an analog sensor such as a Hall effect switch may be used to generate an analog signal, and a digital processor may analyze the analog signal to determine a position of a deflector, the last cartridge, and therefore a number of ammunition remaining in the magazine. It should be noted that N represents the ammunition capacity of the magazine. In some cases, the method may include identifying 3302 a number of active Hall effect switches. In some scenarios, a processor such as a magazine and/or gun processor may be used to evaluate the signals from the Hall Effect switch array.

The method may further include determining 3304 the position of a deflector including a magnet within the magazine based on identifying the number of active Hall effect switches. For example, if a single Hall effect switch is active, the processor may be programmed to identify a first ammunition count based on an active signal from a single Hall effect switch (e.g., the "0" or "2" position in FIG. 18), where each Hall effect switch provides a unique signal or each Hall effect switch is coupled to a different input on the processor. In either case, the processor is configured to distinguish a signal from each of the various Hall effect switches. In some cases, the processor may be configured to store in memory (e.g., on the processor or another memory device in electronic communication with the processor) a correlation between the signal of each Hall effect switch and the remaining ammunition that occurs when a respective switch is aligned with a magnet on the deflector plate. Alternatively, there may be two active Hall effect switches (e.g., the "1" or "3" positions in FIG. 18). In this case, the processor may be programmed to associate this identification of a second ammunition count based on two active signals from two adjacent Hall effect switches. In some other cases, if two Hall effect switches are active, the deflector plate may be located approximately between the two switches, as shown in FIG. 18.

Although method 3300 only refers to a single magnet interacting with one or two Hall effect switches, in other embodiments, more than two magnets may be used, such as the two magnets shown in FIG. 19 or the three magnets shown in FIG. 20.

In some cases, the method may also include obtaining 3306 the number of cartridges in the magazine based on determining the position of the ejector within the magazine. For example, using the two schemes described in 3304, a processor can distinguish each cartridge position even if <N Hall Effect switches are used.

FIG. 41 illustrates a method 4100 for obtaining the number of ammunition in a magazine using an ammunition counting system having a Hall effect switch array. The method 4100 may be implemented by a processor receiving computer readable instructions from one or more tangible programmable computer readable media. In some cases, the computer readable medium may be configured on the processor or a single chip system that is the same as the processor. The processor may receive data from other parts of the system (such as from the Hall effect switch array) and provide data and instructions to other parts of the system. The system includes at least a processor on or in the magazine for evaluating data from the Hall effect switch array, which is also referred to as a magazine processor. In some cases, the processor may be located on the gun and may be referred to as a gun processor. The system may further include at least an array of Hall effect switches and an electrical data connection between the switches and the processor (such as a magazine processor). If located on the magazine, the magazine processor may be configured to transmit the ammunition count data to a wireless interface across an air gap between the magazine and the gun. This may include an NFC interface with two opposing NFC antennas, one NFC antenna configured on or in the magazine and one NFC antenna configured on the gun (e.g., in the magazine compartment). In some embodiments, the gun side of the NFC interface may be configured to pass the ammunition count to a second processor on the gun. The ammunition count can be used by this second processor in a variety of ways (such as sending commands to a display or sending the ammunition count outside the gun).

A processor (such as a magazine processor) may be configured to monitor signals from the Hall effect switches in the array to determine a round count in the magazine. These may be analog signals. Alternatively, the analog signal may first pass through an analog-to-digital converter to thereby provide a digital signal to the processor. In some embodiments, the processor is configured to analyze several different signal configurations from the Hall effect switches. However, to reduce the number of switches used, the processor may be configured to determine a round count based on signals from switches (or sensors) that are less than the number of cartridges that can be loaded into the magazine. For example, N may be defined as a maximum number of rounds that a magazine can hold. In one embodiment, there may be N/2 switches and the processor may be configured to determine an accurate ammunition count based on the signals from the N/2 switches (or sensors). This allows for fewer switches per ammunition position thereby reducing cost. However, to implement this cost reduction, the processor needs to determine the ammunition position in the magazine by distinguishing between positions aligned with or adjacent to a switch and positions between two switches.

In some scenarios, when one or two signals are received by the processor (block 4102), the processor may be configured to first determine whether one or two signals are received (decision block 4104). Decision 4104 entails determining whether one or two signals are received (i.e., a magnet on the deflector is aligned with one switch or with a position between two switches). If the processor determines that a single switch is active, it may be configured to query a lookup table using an identification of the active switch and responsively receive a round count (block 4106). Alternatively, if the processor determines that the two magnetic switches are active, it may be configured to query a lookup table using the identification of the two active switches and responsively receive a cartridge count (block 4108). In some cases, other techniques for matching a set of signals to a corresponding value may be implemented without departing from the scope of the present invention. In some embodiments, the magazine processor may be configured to transmit the cartridge count corresponding to the active switch or switches via an NFC antenna or another substantially planar antenna in the magazine. In some cases, this may include transmitting the ammunition count across a wireless NFC interface (block 4110) to another processor (such as a firearm processor), which may convert the ammunition count into display instructions that direct a display to indicate the ammunition count via a display or other component, such as described with respect to FIGS. 21 and 22.

As previously described, in some cases, the NFC interface may include: a magazine side of the NFC interface, which may include a first NFC or other type of antenna (e.g., a first substantially planar antenna); and a gun side of the NFC interface, which may include a second NFC or other type of antenna (e.g., a second substantially planar antenna). In some embodiments, the magazine side antenna may be disposed within the magazine, such as within a recess in the magazine covered with an insulating or dielectric material (such as a polymer similar to the polymer from which the magazine may be formed). In some other cases, the magazine side antenna (i.e., the first substantially planar antenna) and/or a circuit board or circuit assembly coupled to the antenna may be overmolded from the same material used to form the magazine. In some examples, the gun side antenna (i.e., the second substantially planar antenna) can be disposed within a magazine compartment of the gun. In some cases, the first substantially planar antenna can be disposed in a region of a magazine configured to at least partially fit within a magazine compartment of the gun and parallel to a firing direction of the gun. Furthermore, the first substantially planar antenna and the second substantially planar antenna can both be substantially aligned such that one antenna (e.g., the gun side antenna) completely covers the other antenna (e.g., the antennas are aligned and one antenna is larger than the other antenna). The side-of-the-gun antenna may be disposed on a circuit board or flexible circuit board and shaped and sized to self-align with features of the magazine well so that the side-of-the-gun antenna may be easily installed by a factory worker or user and still maintain alignment with the magazine-side antenna.

In another aspect of the invention, an ammunition counting kit may be added to a gun. In one embodiment, the kit may include a modified magazine and an antenna attachable to the gun. In another embodiment, the kit may include a replacement deflector for an existing magazine, a magazine subassembly, and an antenna attachable to the gun. A method of using the kit to modify a gun may include replacing a deflector of a magazine of a gun with a deflector having a magnet or adding a magnet to an existing deflector. The modification may also include adding a Hall effect switch array to the magazine. This addition may include sliding a thin circuit board into the magazine and adhering it to an inner surface of the magazine in a final position similar to that seen in FIG. 5 . Alternatively, holes may be drilled through the side of an existing magazine into the interior of the magazine so that a Hall effect switch may be secured within each hole. A processor may then be attached to an interior or exterior of the magazine, and electrical leads may be formed between the switch and the processor. For example, these leads may run along an exterior surface of the magazine and may be individually attached or deposited on the surface of the magazine. Alternatively, the leads may be attached as part of a single thin circuit board that may be attached to an exterior of the magazine, still in electrical communication with the Hall effect switch. For example, a small amount of fluid conductor may be deposited in each of the above-mentioned holes and in contact with each of the Hall effect switches to serve as an electrical "pathway" between each switch and an exterior surface of the magazine. A circuit board or electrical leads may then be electrically coupled to these pathways and the processor. In another alternative, one of the inner or outer surfaces of the magazine may be hollowed out or initially formed with an elongated depression. A circuit board may then be attached to one surface of the depression and the circuit board may be overmolded to thereby secure it to the magazine and protect the board from impact, corrosion, dust, etc. In another embodiment, conductive ink may be printed directly onto the magazine surface or into the previously mentioned depression in lieu of a circuit board.

Although circuit boards or circuit assemblies (e.g., PCBs, Hall effect switches, processors, and/or magazine antennas) have been described generally as being located inside the magazine, in other embodiments, these components may be distributed between an interior and exterior of the magazine. For example, the Hall effect switch and processor may be configured inside the magazine and the NFC antenna may be configured on an exterior surface of the magazine. Alternatively, the Hall effect switch may be configured inside the magazine and the processor and antenna may be configured on an exterior surface of the magazine. In any of these variations, a flexible circuit board may be utilized, wherein the flexible circuit board or assembly may be wrapped or folded around a bottom of the magazine to provide a circuit path for data and/or power between the internal components of the magazine and the external components. Alternatively, one or more vias may be used to connect components inside and outside the magazine. In some cases, fewer vias than a number of Hall effect switches may be used. In such cases, multiplexing may be used to send multiple signals from multiple Hall effect switches through a single via to a processor on the outer surface of the magazine. In some embodiments, a processor such as a magazine processor may be configured to recover the individual signals via a process known as demultiplexing (or demultiplexing). In some cases, a via may refer to any hole or opening between the inner and outer surfaces of the magazine, wherein the hole or opening is filled or primarily filled with a conductive material.

Furthermore, in some cases, the processor may include or may be coupled to an antenna such as an RF or NFC antenna. Additionally, another substantially planar antenna such as an NFC antenna may be attached (or glued) to an interior of the magazine compartment, such as shown in FIG. 14. In some embodiments, a planar thin flexible wire/conductor from the antenna may be wrapped or folded around a lower edge of the magazine compartment to thereby provide an electrical connection to components on an exterior of the firearm, such as a display. In this manner, a firearm and magazine may be modified so that the ammunition counting system and method disclosed herein may be implemented on a firearm that does not originally have an ammunition counting system.

Although NFC antennas are typically shown as a planar coil structure (see, for example, FIG. 14 ), various other antenna shapes may be implemented without departing from the scope of the present invention. FIG. 34 -FIG. 40 show some variations of antennas (such as the planar coil antenna seen in FIG. 5 , antenna 1403 in FIG. 14 and FIG. 17 , and the planar coil antenna seen in FIG. 26A and FIG. 26B ).

FIG. 34 shows an embodiment of an NFC antenna 3400 that generally forms a loop but has a plurality of differential steps 3406 for enhancing inductive coupling and flux between the antenna 3400 and a corresponding antenna on an opposite side of an NFC interface (not shown). As shown in the figure, the NFC antenna 3400 may include two input/output connections 3404. In addition, the NFC antenna 3400 may include a conductive trace fabricated on a substrate or a dielectric circuit board, wherein each conductive trace includes a loop and one or more differential steps 3406. This illustrative figure helps to show that other topologies besides a planar coil may be used for the NFC antenna.

FIG. 35 shows an embodiment of an NFC antenna 3500 including a plurality of steps 3506 on both sides of a curved or semicircular length 3508 of the NFC antenna 3500. Similar to FIG. 34, the antenna 3500 may include a conductive trace having one or more steps 3506 and at least one curved or semicircular section 3508, wherein the one or more steps 3506 are arranged on one or more sides of the at least one curved or semicircular section 3508. The antenna 3500 includes two input/output connections 3504. The illustration shows that even an NFC antenna having a topology other than a coil topology may be deployed.

FIG. 36 shows an embodiment of an NFC antenna 3600 including two types of coils formed from the same conductor. In other words, the NFC antenna may include a conductive trace fabricated on a substrate or dielectric circuit board, similar to the antennas depicted in FIGS. 34 and 35 . Specifically, this variation shows a set of rectangular loops or a rectangular coil and a set of diamond loops. In addition, two input/output connections 3604 are also used.

FIG. 37 shows an embodiment of an NFC antenna 3700 comprising a conductive trace fabricated on a substrate or a dielectric circuit board, wherein each conductive trace comprises two linear segments 3708 and a curved segment 3706. In addition, the NFC antenna 3700 comprises two input/output connections 3704.

FIG. 38 shows an embodiment of an NFC antenna 3800 including a conductive trace fabricated on a substrate or a dielectric circuit board, wherein each conductive trace includes three linear segments 3808 parallel to each other and two curved segments 3806 connecting the three linear segments 3808 together. The NFC antenna 3800 also includes two input/output connections 3804.

FIG. 39 shows an embodiment of an NFC antenna 3900 including a conductive trace fabricated on a substrate or a dielectric circuit board, wherein each conductive trace includes a loop 3902a and a secondary conductor 3902b shorting both sides 3906 of the loop 3902a. The NFC antenna 3900 also includes two input/output connections 3904.

FIG. 40 shows an embodiment of an NFC antenna 4000 comprising a conductive trace fabricated on a substrate or a dielectric circuit board, wherein each conductive trace comprises two independent conductor loops 4002a and 4002b. In this embodiment, the two independent conductor loops have a rectangular shape and different sizes. However, in other embodiments, the two loops may have overlapping conductor sections. In some embodiments, one of the conductor loops may be configured to send or receive power, while the second conductor loop may be configured to transmit data. Alternatively, both loops 4002a and 4002b may be configured to transmit the same or separate data streams.

FIG. 42 illustrates a flowchart 4200 of an embodiment of a magazine ammunition count display procedure. The method in flowchart 4200 may be implemented by a processor receiving computer readable instructions from one or more tangible programmable computer readable media. In some cases, the computer readable medium may be configured on a processor or a single chip system that is the same as the processor. The processor may receive data from other parts of the system (such as from a Hall effect switch array) and provide data and instructions to other parts of the system. The system includes at least a processor on or in the magazine for evaluating data from the Hall effect switch array, which may be referred to as a magazine processor. In some cases, the processor may be located on the gun and may be referred to as a gun processor. The system may also include at least an array of Hall effect switches and an electrical data connection between the switches and the processor. If located on the magazine, the processor may transmit the ammunition count data to a wireless interface across an air gap between the magazine and the gun. This may include an NFC interface with two opposing NFC antennas, one NFC antenna disposed on or in the magazine and one NFC antenna disposed on the gun (e.g., in the magazine chamber). In some cases, the NFC antennas in the magazine and/or on the gun may be parallel or substantially parallel to a firing direction of the gun. In other words, the magazine NFC antenna may be mounted along a side of the magazine rather than the spine. In some embodiments, the gun side of the NFC interface can then pass the ammunition count to a second processor on the gun. The ammunition count can be used by this second processor in a variety of ways (such as sending commands to a display or sending the ammunition count outside the gun).

As previously described, a processor such as a magazine processor may be configured to monitor signals from the Hall Effect switches in the array to determine a round count in the magazine. These may be analog signals. Alternatively, the analog signal may be passed through an analog-to-digital converter to thereby provide a digital signal to the processor. In some embodiments, the processor may be configured to analyze several different signal configurations from the Hall Effect switches. In addition, to reduce the number of switches used, the processor may be configured to determine a round count based on signals from switches (or sensors) that are less than the number of cartridges that can be loaded into the magazine. For example, N may be defined as a maximum number of rounds that a magazine can hold. In one embodiment, there may be N/2 switches, and the processor may be configured to determine an accurate ammunition count based on signals from the N/2 switches (or sensors). In some other cases, N/3 or N/4 switches may be utilized. In some embodiments, reducing the number of switches per ammunition position may be used to reduce the cost and/or complexity of installing an ammunition counting system. However, it should be noted that to implement this cost reduction, the processor needs to determine the position of ammunition in the magazine by distinguishing between the position of a magnet aligned with or adjacent to a switch and the position of a magnet between two switches.

In some cases, the process may begin at block 4202, where the processor may determine a unique identifier (or ID) associated with the magazine. In some embodiments, the NFC chip or antenna of the magazine may be associated with a unique identifier. In such cases, for example, after the magazine is inserted into the magazine chamber, the NFC antenna on the gun or in the magazine chamber of the gun may capture the unique ID. In some embodiments, the processor (e.g., the gun processor) may be configured to direct the gun display to display a current ammunition count of the magazine. In some embodiments, a user may also view the most recently recorded ammunition count of any other magazines previously buffered by the gun and/or inserted into the magazine chamber of the gun.

In decision block 4204, the processor may determine whether the bolt of the gun (if present) is open. In some cases, the gun may include an optical sensor, such as at or near a buffer, for determining whether the bolt is open. In some cases, the gun processor may be coupled to the optical sensor and may determine whether the bolt is open or closed based on measurements from the optical sensor. Other types of sensors for determining the state of the bolt are contemplated in different embodiments. In some cases, if the bolt is determined to be open in decision block 4204, the processor may determine that the chamber of the gun is empty. In such cases, the processor may set a chamber ammunition counter (i.e., corresponding to whether there is a round in the chamber) to 0 (block 4206). As shown in the figure, after block 4206, the program may include determining the magazine ammunition count in block 4216 and displaying the magazine ammunition count on a visual display of the gun in 4218. In some cases, the determination and display may be performed according to the techniques described in the present invention including at least FIG. 41.

Alternatively, if it is determined in decision block 4204 that the bolt is not open, the processor may determine in decision block 4208 whether the bolt has cycled. Alternatively, the processor may determine whether there is a round in the chamber based on a reading from an optical sensor or another sensor near the buffer. If so, the processor may set the chamber count to 1 in block 4210. In addition, the process may include determining the magazine round count in block 4220 and displaying the magazine rounds (or transmitting the round count to a display) in 4222. In some cases, in addition to displaying the magazine ammunition count, the processor may also be configured to display a total ammunition count (i.e., chamber count and magazine ammunition count). For example, in block 4222, the process may include adding 1 (i.e., chamber count) to the magazine ammunition count determined in block 4220 and displaying the result on the gun's visual display (or transmitting the ammunition count to a display).

In some cases, if it is determined in decision block 4208 that the bolt has not cycled, the process may include waiting for the bolt to cycle/load (block 4212). After the bolt is loaded, the process may include determining in decision block 4214 whether the ammunition count has been updated. For example, the process may include determining whether the ammunition count has been decremented by 1 based on a round being loaded into the chamber. If so, the process may include: setting the chamber count to 1 in block 4210; determining the magazine ammunition count in 4220; and displaying the ammunition count (e.g., the magazine ammunition count and/or the total ammunition count including the chamber count) in block 4222.

Turning now to FIG. 43 , a method 4300 for retrofitting a magazine using an ammunition counting system is now described. In some cases, the magazine may include at least one overtravel stop and a deflector.

In some embodiments, method 4300 may include mounting 4302 one or more magnets on the ejector plate.

In addition, the method may include configuring 4304 a plurality of magnetic switches (e.g., <N magnetic switches, such as Hall effect switches) substantially along a path of one or more magnets as the deflector moves along a length of the magazine, where N is a maximum number of cartridges that can be loaded into the magazine. In some embodiments, the magnetic switches may be configured to be activated based on a position of one or more magnets relative to the <N magnetic switches and a respective magnetic field at the magnetic switches exceeding a threshold value. In one example, when a magnetic field detected by a magnetic switch exceeds a magnetic field threshold value, the switch may output (e.g., digitally or pulsed) a high signal. Conversely, when a magnetic field detected by the switch is below the magnetic field threshold value, the magnetic switch may output a low signal. In some cases, magnetic field sensing sensors such as Hall effect sensors can be used instead of magnetic switches.

The method 4300 may also include disposing 4306 a first substantially planar antenna on an interior portion of the magazine at or above the over-travel stop (or in a region of the magazine configured to at least partially fit within a magazine chamber of the firearm and parallel to a firing direction of the firearm), the first substantially planar antenna configured to wirelessly transmit at least one of an indication of one or more active magnetic switches, ammunition count data, or an ammunition count indication from the magazine to a second substantially planar antenna on the firearm. In some examples, the ammunition count indication may be based on the ammunition count data, wherein the ammunition count data is related to a retainer position within the magazine, and the ammunition count indication is related to a number of ammunition remaining in the magazine. In other words, the first substantially planar antenna may transmit raw data (i.e., an indication of the active magnetic switch), semi-processed data (i.e., round count data), or fully processed data (i.e., round count indication) to the second substantially planar antenna. In some embodiments, the first substantially planar antenna may transmit raw data or semi-processed data based on the absence of a magazine processor or the limited computing power of a magazine processor, respectively. In other cases, the second substantially planar antenna may directly receive a final round count indication that may be displayed on a gun display, with minimal processing required on the gun side. In some examples, the second substantially planar antenna can transmit power in the opposite direction (i.e., opposite to the data flow) to the first substantially planar antenna, for example, from a power source located on the gun (e.g., the gun grip or stock). In this way, the magnetic processing circuitry and sensors or switches in the magazine can receive power without requiring a power source in the magazine. As mentioned above, the Hall effect switch requires a power source to operate.

In some embodiments, the method may further include configuring 4308 the first substantially planar antenna such that an area of the first substantially planar antenna defined by a height and width is primarily aligned with an area of a second substantially planar antenna coupled to an interior of a magazine chamber of the firearm. Additionally, the first substantially planar antenna and the second substantially planar antenna may be examples of NFC antennas, although other types of RF antennas may be utilized in different embodiments. In some cases, the size and shape of the NFC antenna may be based in part on the data and power requirements of the ammunition counting system. In some embodiments, a first substantially planar antenna (e.g., a magazine-side antenna) can have a different size than (e.g., smaller than) a second substantially planar antenna, which can be used to facilitate alignment of the two antennas because the larger antenna can substantially overlap the smaller antenna even if it is not perfectly aligned with the smaller antenna.

Turning now to FIG. 44 , a method 4400 of manufacturing a magazine having an ammunition counting system is now described. In some cases, the magazine may include at least one overtravel stop and a deflector, wherein the deflector includes one or more magnets. In some examples, the method 4400 implements one or more aspects of the figures described herein.

The method may include configuring 4402 a plurality of magnetic switches (e.g., <N magnetic switches, such as Hall effect switches) substantially along a path of one or more magnets as the deflector moves along a length of the magazine, where N is a maximum number of cartridges that can be loaded into the magazine. In some embodiments, the magnetic switches may be configured to be activated based on a position of the one or more magnets relative to the <N magnetic switches and a respective magnetic field at the magnetic switches exceeding a threshold value. In one example, when a magnetic field detected by a magnetic switch exceeds a magnetic field threshold value, the switch may output (e.g., digitally or pulsed) a high signal. Conversely, when a magnetic field detected by the switch is below the magnetic field threshold value, the magnetic switch may output a low signal. In some cases, magnetic field sensing sensors such as Hall effect sensors can be used instead of magnetic switches.

The method 4400 may also include disposing 4404 a first substantially planar antenna on an interior portion of the magazine at or above the over-travel stop (or in a region of the magazine configured to at least partially fit within a magazine chamber of the firearm and parallel to a firing direction of the firearm), the first substantially planar antenna configured to wirelessly transmit at least one of an indication of one or more active magnetic switches, ammunition count data, or an ammunition count indication from the magazine to a second substantially planar antenna on the firearm. In some examples, the ammunition count indication may be based on the ammunition count data, wherein the ammunition count data is associated with a retainer position within the magazine, and the ammunition count indication is associated with a number of ammunition remaining in the magazine. In other words, the first substantially planar antenna may transmit raw data (i.e., an indication of the active magnetic switch), semi-processed data (i.e., round count data), or fully processed data (i.e., round count indication) to the second substantially planar antenna. In some embodiments, the first substantially planar antenna may transmit raw data or semi-processed data based on the absence of a magazine processor or the limited computing power of a magazine processor, respectively. In other cases, the second substantially planar antenna may directly receive a final round count indication that may be displayed on a gun display, with minimal processing required on the gun side. In some examples, the second substantially planar antenna can transmit power in the opposite direction (i.e., opposite to the data flow) to the first substantially planar antenna, for example, from a power source positioned on the gun (e.g., the gun grip). In this way, the magnetic processing circuitry and sensors or switches in the magazine can receive power without requiring a power source in the magazine. As mentioned above, the Hall Effect switch requires a power source to operate.

Additionally, the method may include configuring 4406 the first substantially planar antenna such that an area of the first substantially planar antenna defined by a height and a width is primarily aligned with an area of the second substantially planar antenna coupled to an interior of a magazine compartment of the firearm.

FIG. 45 illustrates a method 4500 for detecting and displaying a number of cartridges remaining in one or more firearm magazines, each firearm magazine comprising: a deflector including one or more magnets; a magnetic switch disposed substantially along a path of the one or more magnets as the deflector moves along a length of the magazine, and wherein the magnetic switch is configured to activate based on a respective magnetic field at the magnetic switch exceeding a threshold value. In some embodiments, the magnetic switch may include a Hall effect switch, although other types of magnetic switches such as reed switches are contemplated in various embodiments. Alternatively, in some embodiments, a magnetic field sensing sensor such as a Hall effect sensor may be utilized in place of the magnetic switch. Method 4500 implements one or more aspects of the figures described herein. In addition, method 4500 may be implemented by a non-transitory tangible computer-readable storage medium encoded with processor-readable instructions.

In some examples, a non-transitory tangible computer-readable storage medium encoded with processor-readable instructions (also described with respect to FIG. 11 ) can be configured to assign 4502 one or more unique identifiers to one or more first substantially planar antennas, wherein each unique identifier is associated with one first substantially planar antenna.

The method 4500 may further include identifying 4504 a respective ammunition count indication for each gun magazine inserted into a magazine chamber of the gun. In some embodiments, the method 4500 may include temporarily storing 4506 a respective ammunition count indication for each gun magazine inserted into the magazine chamber of the gun and a unique identifier of a first substantially planar antenna assigned to the respective gun magazine, wherein a second substantially planar antenna is configured to receive the unique identifier after the respective gun magazine is inserted into the magazine chamber. In some embodiments, the first substantially planar antenna and the second substantially planar antenna may be examples of NFC antennas, although other types of RF antennas are also contemplated. As mentioned above, in some cases, the first substantially planar antenna may be disposed in a region of a magazine configured to at least partially fit within a magazine chamber of a firearm and/or parallel to a firing direction of the firearm. Additionally, the first substantially planar antenna may be configured to transmit data (e.g., an indication of an active magnetic switch, ammunition count data, ammunition count indication) to a second substantially planar antenna and wirelessly receive power from the second substantially planar antenna. In some cases, the second substantially planar antenna may be coupled to a power source or battery in the firearm, wherein the power source or battery may be located in the stock, at or near the trigger guard, in a grip of the firearm, to name a few non-limiting examples.

In some cases, temporarily storing may include storing the ammunition count indication and unique identifier of each magazine previously inserted into the gun and the ammunition count indication and unique identifier of a magazine currently in the gun. In some embodiments, the ammunition count indication and unique identifier may be stored in a memory of the gun (e.g., an internal memory of a gun processor or another memory device of the gun that is in electronic communication with the gun processor). Additionally, the ammunition count indication and unique identifier may also be stored in the magazine processor's internal memory, which may allow a user to call up the ammunition count indication of other magazines that were previously displayed to the user, even if the user stored the magazine while using one of a different firearm.

In some embodiments, method 4500 may further include displaying 4508 respective ammunition count indications for one or more gun magazines on a user interface on the gun, wherein the user interface is selected from the group consisting of: a number (or numbers) displayed on a red dot scope or an aiming display, a frequency of a flashing light, a color of one or more lights, a number displayed on a multi-pixel display, a number of LED lights lit on an LED display, an audible signal, a fuel gauge indicator, or a bar graph indicator. In some cases, the user can filter the ammunition count indication displayed on the user interface based on a type of weapon (e.g., automatic or semi-automatic rifle, pistol, shotgun, sniper rifle, heavy weapon, to name a few non-limiting examples). This can be applied when the display is linked to multiple weapons and therefore multiple reader antennas/processors. For example, the display can provide a squad leader with carry data for all weapons in a squad or can provide carry data for multiple weapons carried by a single soldier or law enforcement officer.

Additional embodiments

Some embodiments of the present invention may be characterized as an ammunition counting system for a firearm having a detachable magazine, the system comprising a magazine including at least one deflector plate, the deflector plate including one or more magnets, and the magazine including: <N magnetic field sensing sensors disposed substantially along a path of the one or more magnets as the deflector plate moves along a length of the magazine, wherein N is a maximum number of cartridges that can be loaded into the magazine, the sensors sensing the one or more magnets relative to the <N magnetic field sensing sensors based on the <N magnetic field sensing sensors sensing the <N magnetic field sensing sensors. a position of a detector to generate ammunition count data; and a first substantially planar antenna located on an interior of the magazine, disposed in an area of the magazine configured to be at least partially mounted within a magazine chamber of the firearm, the wireless antenna being configured to wirelessly transmit an ammunition count indication from the magazine to a substantially planar second antenna on the firearm; and the substantially planar second antenna being configured to be attached to an interior of a magazine chamber of the firearm and having an area that substantially overlaps an area of the first substantially planar antenna.

Other embodiments of the invention may also be characterized as an ammunition counting system for a firearm having a detachable magazine, the system comprising a magazine including a deflector including one or more magnets, and the magazine including: Hall effect switches substantially disposed along a path of the one or more magnets, wherein N is a maximum number of cartridges that can be loaded into the magazine, the Hall effect switches each generating a high or low signal based on a position of the one or more magnets relative to each of the Hall effect switches; and a magazine processor coupled to the Hall effect switches. each of which should be switched and is configured to convert the high or low signal from each of the Hall effect switches into a single ammunition count indication of the magazine; a magazine antenna located on an interior of the magazine, disposed in an area of the magazine configured to fit at least partially within a magazine chamber of the firearm, the magazine antenna being configured to wirelessly transmit the ammunition count indication from the magazine to a magazine chamber antenna on the firearm; and the magazine chamber antenna being configured to attach to an interior of a magazine chamber of the firearm and having an area that substantially overlaps an area of the magazine antenna.

Other embodiments of the present invention may be characterized as a method of manufacturing a magazine having an ammunition counting system, the magazine including a deflector, wherein the deflector includes one or more magnets, the method comprising: disposing <N magnetic field sensing sensors substantially along a path of the one or more magnets as the deflector moves along a length of the magazine, wherein N is a maximum number of cartridges that can be loaded into the magazine, the sensors generating ammunition count data based on a position of the one or more magnets relative to the <N magnetic field sensing sensors; and A first substantially planar antenna is disposed on an interior portion of a magazine in an area of the magazine that is sub-assembled in a magazine chamber of a gun, the first substantially planar antenna being configured to wirelessly transmit an ammunition count indication from the magazine to a substantially planar second antenna on the gun, the ammunition count indication being based on the ammunition count data, wherein the first substantially planar antenna is configured such that an area of the first substantially planar antenna defined by a height and a width is primarily aligned with an area of a second substantially planar antenna coupled to an interior portion of a magazine chamber of the gun.

Other embodiments of the invention may be characterized as a method of mounting an ammunition counting system on a firearm, the method comprising: mounting a removable magazine including a feeder, the feeder including one or more magnets, and the magazine including: <N magnetic field sensing sensors substantially arranged along a path of the one or more magnets as the feeder moves along a length of the magazine, wherein N is a maximum number of cartridges that can be loaded into the magazine, the sensors generating an ammunition counting signal based on a position of the one or more magnets relative to the <N magnetic field sensing sensors. and a first substantially planar antenna located on an interior of the magazine, disposed in an area of the magazine configured to be at least partially mounted in a magazine chamber of the gun; and a second substantially planar antenna mounted on an interior of a magazine chamber of the gun, such that an area of the first substantially planar antenna is substantially aligned with an area of the second substantially planar antenna, the first substantially planar antenna and the second substantially planar antenna being configured to exchange an ammunition count indication and power based on the ammunition count data via a near field communication connection.

Other embodiments of the invention may be characterized as a non-transitory tangible computer-readable storage medium encoded with processor-readable instructions to execute a method for detecting and displaying a number of cartridges remaining in a firearm magazine, the firearm magazine including a deflector, and the deflector including one or more magnets, the method comprising: disposing <N magnetic field sensing sensors substantially along a path of the one or more magnets as the deflector moves along a length of the firearm magazine, wherein N is a maximum number of cartridges that can be loaded into the firearm magazine, the sensors generating a signal based on a position of the one or more magnets relative to the <N magnetic field sensing sensors; ammunition count data; a first substantially planar antenna is disposed on an interior portion of a magazine of a firearm in an area of the magazine configured to be at least partially mounted within a magazine chamber of the firearm, the first substantially planar antenna being configured to exchange an ammunition count indication and power based on the ammunition count data with a second substantially planar antenna coupled to an interior portion of a magazine chamber of the firearm via a near field communication connection, wherein the first substantially planar antenna is configured such that an area of the first substantially planar antenna defined by a height and a width is primarily aligned with an area of the second substantially planar antenna coupled to the interior portion of the magazine chamber of the firearm.

In some embodiments, the magazine may include a display indicating the ammunition count. This display may be powered by power transferred from the gun to the magazine via the NFC interface. When the magazine is removed from the gun, the display may enter a static mode that consumes no power (e.g., LCD). Alternatively, such a magazine display may be powered by a battery on the magazine.

Although the present invention has discussed specific locations of magnets on the flipper (generally orienting the magnets as close as possible to the Hall Effect switch), in some embodiments, the magnets may be located on other portions of the flipper.

The embodiments herein have discussed a magnet and a distance between the magnet and the Hall Effect switches that allows one or two switches to be engaged at a time or above all switching thresholds. However, in some embodiments, a stronger magnet or multiple magnets may be used, and in such cases, three or more switches may be engaged when the flapper is in a particular position, which may result in more reliable flapper position sensing and/or may result in the ability to use fewer than N/2 switches.

Portions of the present invention are presented in the form of algorithms or symbolic representations of operations on data bits or binary digital signals stored in a computing system memory (such as a computer memory). Such algorithmic descriptions or representations are examples of techniques used by those of ordinary skill in the data processing arts to convey the substance of their work to others skilled in the art. An algorithm is a self-consistent sequence of operations or similar processing leading to a desired result. In the present invention, the operations or processing involve physical manipulations of physical quantities. Typically, but not necessarily, such quantities may take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, or otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, data, values, elements, symbols, characters, terms, numbers, numerical values, or the like. It will be understood, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels. Unless expressly stated otherwise, it will be understood that discussions in this specification utilizing terms such as "processing," "operating," "computing," "determining," and "recognizing," or their equivalents, involve actions or procedures of a computing device, such as one or more computers or similar electronic computing devices, that manipulate or transform data represented as physical electronic or magnetic quantities within a memory, register, or other information storage device, a transmission device, or a display device of a computing platform.

Some portions are presented in the form of algorithms or symbolic representations of operations on data bits or binary digital signals stored in a computing system memory, such as a computer memory. Such algorithmic descriptions or representations are examples of techniques used by those of ordinary skill in the data processing arts to convey the substance of their work to others skilled in the art. An algorithm is a self-consistent sequence of operations or similar processing leading to a desired result. In the present invention, the operations or processing involve physical manipulations of physical quantities. Typically, but not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, or otherwise manipulated. It proves convenient at times, principally for reasons of common usage, to refer to these signals as bits, data, values, elements, symbols, characters, terms, numbers, numerals, or the like. However, it should be understood that all such and similar terms are associated with the appropriate physical quantities and are merely convenient labels. Unless expressly stated otherwise, it should be understood that in this specification, discussions using terms such as "processing," "computing," "calculating," "judging," and "recognizing," or their equivalents, involve actions or procedures of a computing device, such as one or more computers or similar electronic computing devices, that manipulate or transform data represented as physical electronic or magnetic quantities in a memory, register, or other information storage device, transmission device, or display device of a computing platform.

Those skilled in the art will appreciate that aspects of the present invention may be embodied as a system, method, or computer program product. Thus, aspects of the present invention may be in the form of a complete hardware implementation, a complete software implementation (including firmware, resident software, microcode, etc.), or an implementation combining software and hardware aspects, all of which may be generally referred to herein as a "circuit," "module," or "system." In addition, aspects of the present invention may be in the form of a computer program product embodied in one or more computer-readable media having computer-readable program code embodied thereon.

As used herein, the statement "at least one of A, B, and C" is intended to mean "A, B, C, or any combination of A, B, and C". The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications of these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but should be given the broadest scope consistent with the principles and novel features disclosed herein.

102: Guns

104: Magazine

106: Bulletproof plate

108:Magnet

110: Compression spring

112: Magnetic sensor

114: Bulletproof plate seat

115: Fork teeth

116: Processing circuit system/processor

118: Transmitter

120: Receiver

122: Display device

Claims (20)

An ammunition counting system for a firearm having a detachable magazine, the system comprising: a deflector including one or more magnets; and a magazine including: a plurality of magnetic switches disposed substantially along a path of the one or more magnets as the deflector moves along a length of the magazine, the magnetic switches configured to wirelessly transmit at least one of an indication of one or more active magnetic switches of the magnetic switches, ammunition count data, or an indication of an ammunition count to a second antenna in the magazine chamber based on a position of the one or more magnets relative to the magnetic switches; and a first antenna disposed in a region of the magazine configured to at least partially fit within a magazine chamber of the firearm, the first antenna configured to wirelessly transmit at least one of an indication of one or more active magnetic switches of the magnetic switches, ammunition count data, or an indication of an ammunition count to a second antenna in the magazine chamber. A system as claimed in claim 1, wherein the second antenna is mounted in a recess in the magazine chamber without removing material from the magazine chamber. A system as claimed in claim 1, wherein the first antenna is disposed beneath an outer layer of the magazine or is overmolded by a material used to form the magazine. A system as claimed in claim 1, wherein the magazine includes <N magnetic switches, where N is a maximum number of cartridges that can be loaded into the magazine. The system of claim 1, wherein the first antenna is associated with a unique identifier, and wherein the second antenna is configured to receive the unique identifier after the magazine is inserted into the magazine chamber of the firearm. The system of claim 5, further comprising a gun processor configured to be coupled to the gun and to be in electrical communication with the second antenna, the gun processor comprising a tangible computer-readable medium encoded with computer-readable instructions, and wherein the gun processor is configured to store an ammunition count indication and the unique identifier associated with the first antenna and another ammunition count indication and the unique identifier associated with an antenna of another magazine previously inserted into the magazine chamber of the gun. A system as claimed in claim 6, wherein the magazine includes <N magnetic switches, where N is a maximum number of cartridges that can be loaded into the magazine. A system as claimed in claim 1, wherein the first antenna receives power wirelessly from the gun, and wherein the power is used to power the magnetic switches. A system as claimed in claim 8, wherein the first antenna comprises a first independent conductor loop and a second independent conductor loop, the second independent conductor loop having a size different from that of the first independent conductor loop, and wherein the first independent conductor loop is configured to receive the power from the second antenna and the second independent conductor loop is used to send data to the second antenna. A system as claimed in claim 8, wherein the magazine includes <N magnetic switches, where N is a maximum number of cartridges that can be loaded into the magazine. A system as claimed in claim 1, wherein the magnetic switches are Hall effect switches. A system as claimed in claim 1, wherein the first antenna is disposed on a left side or a right side of the magazine. A system as claimed in claim 1, wherein the first antenna is disposed on a bottom surface of the magazine chamber. A non-transitory tangible computer-readable storage medium encoded with processor-readable instructions to execute a method for detecting and displaying a number of cartridges remaining in one or more firearm magazines, each firearm magazine comprising: a deflector including one or more magnets; a plurality of Hall effect switches disposed substantially along a path of the one or more magnets as the deflector moves along a length of the magazine, the Hall effect switches configured to activate based on a respective magnetic field at the Hall effect switches exceeding a threshold value, the method comprising: assigning one or more unique identifiers to the deflector; One or more first antennas, wherein each unique identifier is associated with one first antenna; identifying a respective ammunition count indication for each gun magazine inserted into a magazine chamber of a gun; temporarily storing the respective ammunition count indication and the unique identifier of the first antenna assigned to the respective gun magazine for each gun magazine inserted into the magazine chamber of the gun, wherein a second antenna is configured to receive the unique identifier after the respective gun magazine is inserted into the magazine chamber; and displaying the respective ammunition count indication of the one or more gun magazines on a user interface on the gun. The non-transitory tangible computer-readable storage medium of claim 14, further comprising calling the respective ammunition count indicator when a respective firearm magazine is reinserted into the magazine chamber. A non-transitory tangible computer-readable storage medium as claimed in claim 14, wherein an area of the second antenna is larger than an area of the first antenna. A method of manufacturing an ammunition counting system for a magazine having a deflector, wherein the deflector includes one or more magnets, the method comprising: disposing a plurality of magnetic switches substantially along a path of the one or more magnets in the magazine, wherein the one or more magnetic switches are activated when a magnetic field formed by the one or more magnets exceeds a switching threshold of the one or more magnetic switches; disposing a first antenna in a region of the magazine configured to at least partially fit within a magazine chamber of a firearm, the first antenna being configured to wirelessly transmit at least one of an indication of one or more active magnetic switches, ammunition count data, or an ammunition count indication to a second antenna of the firearm via a near field connection (NFC). The method of claim 17, wherein the first antenna is embedded in a left side or a right side of the magazine and a polymer is overmolded on the top of the first antenna. The method of claim 17, further comprising attaching the second antenna within a recess in the magazine chamber without removing material from the magazine chamber. The method of claim 17, wherein the first antenna is formed by the following steps: forming a first conductive loop for receiving power; and forming a second conductive loop for sending or receiving data.