TWI857498B - Usb slave device and power quality detection method thereof - Google Patents

Abstract

A USB slave device and its power quality detection method, where the USB device is preset to enable only the minimum functions required for the power quality detection. When the USB slave device is connected to a USD power supply, the power quality detection is started and if the USB slave device is not rebooted after a period of time, the power quality check is determined to be passed and full functions of the USB slave device are enabled.

Description

USB slave device and its power quality detection method

The present invention relates to the field of power detection, in particular to a USB slave device and a power quality detection method thereof.

When a USB power supply that is lower than the product specification requirements or does not comply with the USB specification is used to power a USB slave device, it will cause the USB slave device to unexpectedly lose power, restart, or become unable to use certain functions of the product, causing the user to mistakenly believe that the USB slave device is damaged.

In order to improve user experience and reduce unnecessary repair costs, it is necessary to add a power quality detection mechanism to USB slave devices.

In view of this, the purpose of the present invention is to provide a USB slave device and a power quality detection method thereof, which can provide power quality detection in a USB slave device powered by USB.

An embodiment of the present invention provides a USB slave device, including a controller, a power quality detection circuit and a peripheral module, wherein the power quality detection circuit is used to detect the current provided by the USB power supply device; the peripheral module is used to control the enabling and disabling of each function, wherein the peripheral module is preset to enable the minimum functions required to execute the power quality detection method and disable the remaining functions; and the controller, Used to execute the power quality detection method, the power quality detection method includes the following steps: establishing a connection relationship with the USB power supply device; enabling the power quality detection circuit; judging whether the device has not been restarted for a preset time threshold; when judging that the device has not been restarted for a preset time threshold, notifying the peripheral module to enable all functions; and when judging that the device has been restarted, prompting the user to replace the USB power supply device.

An embodiment of the present invention also provides a power quality detection method, which is applied to a USB slave device, wherein the peripheral module of the USB slave device is preset to enable the minimum functions required to execute the power quality detection method and disable the remaining functions. The method includes the following steps: establishing a connection relationship with the USB power supply device; enabling the power quality detection circuit of the USB slave device; determining whether the device has not been restarted for a preset time threshold; when it is determined that the device has not been restarted for a preset time threshold, notifying the peripheral module of the USB slave device to enable all functions; and when it is determined that the device has been restarted, prompting the user to replace the USB power supply device.

By using the above-mentioned USB slave device and its power quality detection method, the power supply capability of the USB power supply device can be detected, thereby reducing the risk of unexpected malfunction or power failure and restart of the USB slave device.

100:USB slave device

110: Controller

120: Power quality detection circuit

121: Switching components

122: Load

130: Peripheral module

200: USB power supply equipment

S201~S205: Steps

Figure 1 is a block diagram of a USB slave device according to an embodiment of the present invention.

Figure 2 is a flow chart of a method for detecting power quality of a USB slave device according to an embodiment of the present invention.

Through the following detailed description of the specific embodiments combined with the attached drawings, it will be easy to understand the above content and the many advantages of this invention.

Please refer to FIG. 1, which is a block diagram of a USB slave device 100 according to an embodiment of the present invention. The USB slave device 100 refers to a device that must be powered by a USB power supply device 200; the USB power supply device 200 refers to a device having a USB port that can actively power the USB slave device 100, as shown in FIG. 1, wherein the USB power supply device 200 is connected to the USB slave device 100 through the USB port. In one example, the USB power supply device 200 includes a computer, a tablet, a smart TV, and a USB charger. The USB slave device 100 includes a controller 110, a power quality detection circuit 120, and a peripheral module 130. The controller 110 includes a microcontroller unit (MCU) for executing the power quality detection method and controlling the operation of the USB slave device 100. The power quality detection circuit 120 includes a switch element 121 and a load 122, which are used to detect whether the USB power supply device 200 can provide the required rated current, wherein the switch element 121 includes a MOS tube or a power switch integrated circuit, and the load 122 includes a plurality of resistors. The peripheral module 130 is used to control the enabling and disabling of each function, wherein each function includes a software module and a hardware component, such as a memory card, Bluetooth, WiFi, and a speaker.

In this embodiment, when the USB slave device 100 is in the prototype stage, the power consumption current value of the whole device, i.e., the rated current, is estimated according to the specification and software functions; when the USB slave device 100 enters trial production, the required minimum power consumption current value is measured and confirmed according to the multiple functions enabled by the software. The switch components that meet the regulatory requirements are selected according to the rated power current, and the appropriate load composition is selected according to the preset rated power current and the minimum power consumption current value.

In one implementation, the peripheral module 130 is pre-set to enable only the minimum functions required to perform power quality detection, such as a memory for reading and writing data, and a communication interface for two-way communication with the USB power supply device 200. For example, when the USB slave device 100 is a smart TV box, the pre-set enabled functions include high-definition multimedia interface, memory, and Bluetooth functions.

Please refer to Figure 2, which is a flow chart of a power quality detection method of a USB slave device in an embodiment of the present invention. In this embodiment, the power quality detection method is executed by a controller of the USB slave device.

Step S201, establish a connection with the USB power supply device.

In one embodiment, after the USB slave device establishes a connection with the USB power supply device, the product identification code PID and the vendor identification code VID of the USB power supply device are obtained, and the USB power supply device is judged whether it is a designated device according to the PID and the VID. When the USB power supply device is judged to be a designated device, step S204 is directly executed. In one example, when the USB slave device determines that the USB power supply device is a transformer attached to the USB slave device when it leaves the factory according to the PID and the VID, the relevant steps of the power quality detection can be skipped and used directly. When the USB slave device cannot obtain the PID and the VID of the USB power supply device, the relevant steps of the power quality detection continue to be executed.

Step S202, enable the power quality detection circuit.

Specifically, an enable signal is sent to the switch element of the power quality detection circuit to turn on the power path and pass through the load of the power quality detection circuit.

In one embodiment, after the USB slave device is powered on, a power detection flag and a full function flag are generated and stored in a memory. The power detection flag is used to indicate whether the power quality test has been performed, 0 represents that the power quality test has not been performed, and 1 represents that the power quality test has been performed; the full function flag is used to indicate the result of the power quality test, 0 represents that the power quality test has not passed, and 1 represents that the power quality test has passed. In this embodiment, the flag values of the two flags are both preset to 0. Each time the USB slave device 100 is restarted, the flag values of the two flags need to be read to confirm the current status of the power quality test.

Before the USB slave device sends an enable signal to the switch element of the power quality detection circuit, the flag value of the power detection flag is set to 1 and stored, indicating that the power quality detection starts.

In one embodiment, the composition of the load is based on the preset power rating current and, for example, the current required by the USB slave device is at least 760 milliamperes (mA), that is, the USB power supply device must at least meet the 900mA required by the USB3.0 protocol. During trial production, it was calculated that the current passing through the load is 600mA, so the load is connected in parallel by two 16-ohm resistors to meet the power quality detection requirements. When the switch element of the power quality detection circuit is enabled, additional current will be generated to pass through the load. At this time, if the USB power supply device is a 500mA power supply device, the USB slave device will directly restart because the current exceeds the current that the USB power supply device can provide. Otherwise, the system will maintain a stable state.

Step S203, determine whether the reboot has not reached the preset time threshold.

When it is determined that the USB slave device maintains a stable state for a preset time threshold and does not restart, step S204 is executed. In one example, the preset time threshold is 5 seconds. On the contrary, when the USB slave device restarts, it means that the power quality test result is not passed. At this time, the flag value of the USB slave device reading the power test flag is 1 and the flag value of the full function flag is 0, which means that the power quality test has not passed, and step S205 is executed.

Step S204, enable all functions.

When the power quality test result is passed, it means that the connected USB power supply device can meet the operation requirements of the USB slave device. Therefore, the peripheral module is notified to enable all functions, and the flag value of the full function flag is set to 1 and stored.

In one example, when the USB slave device is restarted, the flag value of the power detection flag is read as 0 and the flag value of the full function flag is 1. Since it is impossible to set the flag value of the full function flag to 1 without passing the power quality test, it is judged as malfunctioning, the flag value of the full function flag is set to 0, and the power quality test is re-executed.

In one example, when the power quality test result is passed, but the user restarts the USB slave device, the flag values of the power test flag and the flag value of the full function flag read after the power is turned on are both 1. Considering that the user may replace the USB power supply device during the process from shutting down to restarting, in this example, the flag values of the power test flag and the flag value of the full function flag read in real time are both 1, and the flag values of both flags still need to be set to 0 and the power quality test is performed.

Step S205, prompt the user to replace the USB power supply device.

In one embodiment, when the power quality test of the USB slave device fails, the USB slave device prompts the user to replace a suitable USB power supply device or prompts the user that the function of the current USB slave device is limited through one or more LED indicators.

In one embodiment, when the power quality test of the USB slave device fails, the USB slave device sends a prompt message to the USB power supply device. For example, the USB slave device is an OTT Dongle, and the USB power supply device is a TV. The USB slave device can send a prompt message to the display screen output of the USB power supply device to inform the user that a power source that does not meet the specifications is detected, and the user is prompted that the full function of the USB slave device cannot be used at present.

In summary, the USB slave device and its power quality detection method of the present invention can detect whether the USB power supply device used by the user meets the specification requirements of the USB slave device, clarify the causes of unexpected restarts and malfunctions, improve user experience and reduce unnecessary product returns.

It is worth noting that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

S201~S205: Steps

Claims (10)

A USB slave device for executing a power quality detection method comprises a controller, a power quality detection circuit and a peripheral module, wherein the power quality detection circuit is used to detect the current provided by the USB power supply device; the peripheral module is used to control the enabling and disabling of each function, wherein the peripheral module is preset to enable the minimum functions required for executing the power quality detection method and disable the remaining functions; and the controller is used to execute the power quality detection method. The detection method includes the following steps: establishing a connection relationship with the USB power supply device; enabling the power quality detection circuit; determining whether the USB slave device has not been restarted for a preset time threshold; when it is determined that the USB slave device has not been restarted for a preset time threshold, notifying the peripheral module to enable all functions; and when it is determined that the USB slave device has been restarted, prompting the user to replace the USB power supply device. The USB slave device as described in claim 1, wherein the power quality detection circuit includes a switch element and a load, and the step of enabling the power quality detection circuit includes: sending an enable signal to the switch element to turn on the power path and pass the power through the load. The USB slave device as described in claim 1, wherein the step of prompting the user to replace the USB power supply device includes: prompting the user via the LED indicator light of the USB slave device. The USB slave device as described in claim 1, wherein the step of prompting the user to replace the USB power supply device comprises: the USB slave device transmits a prompt message to the USB power supply device; and the display screen of the USB power supply device outputs the prompt message. A USB slave device as described in claim 2, wherein the composition of the load is set according to a preset power rated current and a minimum power consumption current value. A power quality detection method is applied to a USB slave device, wherein the peripheral module of the USB slave device is preset to enable the minimum functions required to execute the power quality detection method and disable the remaining functions. The power quality detection method includes the following steps: establishing a connection relationship with a USB power supply device; enabling the power quality detection circuit of the USB slave device; determining whether the USB slave device has not been restarted for a preset time threshold; when it is determined that the USB slave device has not been restarted for a preset time threshold, notifying the peripheral module to enable all functions; and when it is determined that the USB slave device has been restarted, prompting the user to replace the USB power supply device. As described in claim 6, the power quality detection method, wherein the power quality detection circuit includes a switch element and a load, and the step of enabling the power quality detection circuit includes: sending an enable signal to the switch element to turn on the power path and pass the power through the load. As described in claim 6, the power quality detection method, wherein the step of prompting the user to replace the USB power supply device includes: prompting the user via the LED indicator light of the USB slave device. As described in claim 6, the power quality detection method, wherein the step of prompting the user to replace the USB power supply device comprises: the USB slave device transmits a prompt message to the USB power supply device; and the display screen of the USB power supply device outputs the prompt message. As described in claim 7, the power quality detection method, wherein the composition of the load is set according to the preset power rated current and the minimum power consumption current value.

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