CN101751768B - Decoding method and device thereof - Google Patents

Abstract

The invention discloses a decoding method and a device thereof, which can solve the problem of decoding deformed sequence codes. The decoding device of the present invention is used to decode a sequence code, the sequence code includes at least one initial pulse wave and a plurality of data pulse waves, and the decoding device includes: a detection unit for detecting the initial pulse wave , to generate a notification signal; a determination unit, used to determine a sampling period according to the notification signal and the pulse width of a data pulse among the data pulses; and a decoding unit, used to determine a sampling period according to the data pulse The sampling period decodes the data pulses.

Description

Decoding method and device thereof

technical field

The invention relates to a remote control command decoding method and its device, in particular to an infrared remote control command decoding method and its device which can automatically adjust the sampling period.

Background technique

The technology used by conventional remote control devices is mainly infrared (IR) or radio frequency (Radio Frequency) technology. Among them, the infrared remote control device has become a widely used remote control technology due to its advantages of small size, low power consumption and low cost. For example, US Patent No. 4,426,662 is an infrared remote control device. example.

Infrared remote control devices generally have two terminals, sending and receiving. The transmission of instructions between the two terminals requires a set of encoding and decoding standards in order to effectively transmit and identify instructions. As disclosed in US Patent No. 4,426,662 An infrared remote control decoding technology at the receiving end. The encoding formats of infrared remote control commands are mainly divided into two categories. The first category is the RC-5 code and RECS80 code commonly used in Europe, and the other is the NEC code commonly used in the Far East.

Figure 1 shows an infrared remote control command encoding format of the known NEC code, which adopts the Pulse Width Modulation method (Pulse Width Modulation), including a leader pulse (or initial pulse) and a 16-digit user code (8-bit user code and its 8-bit complement), and 16-bit data code (8-bit data code and its 8-bit complement). The binary representation of the format in Figure 1 is shown in Figure 2. The pulse width (high level) is about 0.56 milliseconds (ms, millisecond), the low level is about 0.56 milliseconds, and the period is about 1.125 milliseconds to represent binary "0". ; The high level is about 0.56 milliseconds, the low level is about 1.68 milliseconds, and the period is about 2.25 milliseconds to represent binary "1". In addition, the high level of the initial pulse wave is about 9 milliseconds, the low level is about 4.5 milliseconds, and the period is about 13.5 milliseconds.

After the sending end of the infrared remote control sends out the remote control command, the receiving end must decode the remote control command (for 16-bit data code and user code) to identify the meaning of the command. Taking the above-mentioned NEC code as an example, one of the decoding methods is described below. In a common decoding method, it is calculated from the falling edge of the waveform of a certain bit in the instruction sequence code to the rising edge of the adjacent waveform (that is, the low level period) to identify the corresponding binary instruction. As in the above-mentioned NEC code encoding format, assuming that the frequency period used is 1 microsecond (μs, microsecond), "0" is 0.56 milliseconds in the high level and 0.56 milliseconds in the low level; "1" is 0.56 milliseconds in the high level and 1.68 milliseconds in the low level. Therefore, when the frequency from the falling edge of the waveform to the rising edge of the adjacent waveform is about 560 (0.56ms/1μs), the corresponding bit is decoded as "0"; when the falling edge of the waveform to the rising edge of the adjacent waveform When the number of frequencies passed by the edge is about 1680 (1.68ms/1μs), the corresponding bit is decoded as "1", so that the binary state of the command bit can be identified through the calculation of the number of frequencies.

In the above decoding method, two frequency intervals need to be preset before judging the data bit value. For example, the frequency intervals are 550-570 and 1670-1690. When the frequency number falls within the interval of 550-570, it represents the bit value "0". On the contrary, when the frequency number passed by the falling edge of the waveform to the rising edge of the adjacent waveform falls within the interval of 1670-1690, it represents the bit value "1". "However, the infrared remote control command sometimes causes the change of the pulse waveform after being transmitted, for example: the pulse width becomes longer or shorter. In this case, the conventional technology uses a decoding method with a fixed frequency interval to convert Unable to decode correct instruction bit value.

Contents of the invention

The technical problem to be solved by the present invention is to provide a decoding method and its device, which can solve the problem of decoding deformed sequence codes.

In order to solve the above technical problems, the present invention provides the following technical solutions:

The present invention provides a decoding method for decoding a sequence code, the sequence code includes at least one initial pulse wave and complex data pulse waves, the decoding method includes the following steps: receiving a sequence code; detecting the sequence code the initial pulse; after detecting the initial pulse, determine a sampling period according to the pulse width of a data pulse in the data pulses; and perform a sampling cycle on the data pulses according to the sampling period decoding.

In the above step of detecting the initial pulse wave, when the pulse width of a pulse wave exceeds the default value, it is determined that the pulse wave is the initial pulse wave. In the step of decoding the data pulses according to the sampling period, when the interval between a data pulse in the complex data pulses and the next adjacent data pulse is not greater than a predetermined sampling period When a first bit value is generated; when the interval between a data pulse wave and the next adjacent data pulse wave among the plurality of data pulse waves is greater than the predetermined sampling period, a second bit value is generated.

The present invention further provides a decoding device for decoding a sequence code, the sequence code includes at least one start pulse and a plurality of data pulses, the decoding device includes: a detection unit for detecting the start start pulse, to generate a notification signal; a determination unit, used to determine a sampling period according to the notification signal and the pulse width of a data pulse in the data pulses; and a decoding unit, used to determine a sampling period according to The sampling period decodes the data pulses.

In the above-mentioned decoding device, when the pulse width of a pulse is greater than the default value, the detection unit determines that the pulse is the initial pulse. Preferably, the above-mentioned decoding device further includes a memory unit for storing the decoded data output by the decoding unit.

The decoding method and device adopted in the present invention utilize the pulse width of the received serial code to generate a sampling period, and decode the serial code according to the sampling period, thus solving the problem of decoding deformed serial codes. Moreover, even if the pulse waveform of the infrared remote control command is deformed during transmission, the correct command value can still be decoded.

Description of drawings

FIG. 1 shows a schematic diagram of a conventional infrared remote control instruction encoding format.

FIG. 2 shows a schematic representation of binary bits in the encoding format of FIG. 1 .

FIG. 3 shows a flowchart of an embodiment of the decoding method of the present invention.

4(a) and 4(b) respectively show schematic diagrams of a binary decoding method according to an embodiment of the present invention.

FIG. 5 shows a block diagram of an embodiment of the decoding device of the present invention.

FIG. 6 shows a block diagram of a preferred embodiment of the decoding device of the present invention.

[Description of main component symbols]

500 decoding device 510 detection unit

520 decision unit 530 decoding unit

600 decoding device 610 detection unit

620 decision unit 621 counter

622 latch 630 decoding unit

640 memory cells

Detailed ways

In order to further understand the above-mentioned purpose, functions, features and advantages of the present invention, preferred embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Fig. 3 is a flow chart showing the decoding method of an infrared remote control instruction according to an embodiment of the present invention. For the convenience of explaining the decoding method of the present invention, the following embodiments are all illustrated with NEC codes as an example, but not used to limit the invention.

After the infrared remote control command serial code is input (received), step 301 first detects the initial pulse wave of the serial code. Generally speaking, the pulse width of the initial pulse wave of the infrared command serial code is the pulse width of the data pulse wave Therefore, when it is detected that the pulse width of a pulse wave in the serial code exceeds the data pulse width by a large amount, it can be judged that the pulse wave is the initial pulse wave. Taking the NEC code as an example, the NEC code The pulse width of the initial pulse is about 9 milliseconds, and the pulse width of the data pulse is about 0.56 milliseconds. Therefore, if the detected pulse width (high level period) exceeds a default value (for example, 2 milliseconds), Then it is determined that the pulse wave is the initial pulse wave.

In step 302, the sampling period for decoding the sequence code is calculated. After the initial pulse is confirmed, the pulse width of the data pulse following the initial pulse is calculated, and the pulse width is used as the sampling period for decoding the sequence code data bits. In the encoding format of the NEC code, the pulse width of the data pulse (high level period) is fixed, and the low level period is generally changed to represent the binary "0" or "1" bit value respectively. Therefore, the sampling period That is, the pulse width (high level period) of each serial code bit, that is, 0.56 milliseconds, if the waveform of the serial code is deformed due to the transmission process, then step 302 can calculate the pulse width after deformation, and use the pulse width As the sampling period for decoding. In one embodiment, the sampling period is obtained by calculating the pulse width of the first data pulse following the initial pulse.

In step 303, the data bit (i.e. data pulse wave) in the sequence code is decoded with the sampling period obtained in step 302, which means to judge the binary "0" represented by the user code or data code bit in the sequence code " or "1" bit value. In this embodiment, step 303 is to detect the interval between every two pulses in the serial code (for example, the falling edge of a data pulse in the serial code to the rising edge of the waveform of the adjacent pulse) through sampling according to the sampling period. The number of cycles, to identify the corresponding bit value, please refer to the schematic diagram shown in Figure 4(a), which is described by taking the data bits of the NEC code as an example. When the interval between two pulse waves is detected to be less than 2 During the sampling period, this bit represents a binary "0", as shown in Figure 4(b), when the detected result is greater than or equal to 2 sampling periods, this bit represents a binary "1". In another embodiment, the number of sampling periods elapsed from the rising edge of a data pulse to the rising or falling edge of an adjacent pulse can be detected according to the sampling period to determine the bit value represented by the data bit. In the decoding method of the present invention, the sampling period on which the decoding is based is generated by the actually received pulse width. Even if the infrared command sequence code has a waveform deformation during the transmission process, under normal circumstances, the pulse wave deformation Therefore, the correct decoding result can still be obtained by taking the sampling period generated by the deformed pulse width as the basis for decoding.

FIG. 5 shows a schematic diagram of an embodiment of a decoding device for infrared control commands according to the present invention. As shown in FIG. 5 , the decoding device 500 of the present invention includes a detection unit 510, a decision unit 520, and a decoding unit 530 . The detection unit 510 is used to detect the initial pulse wave of the serial code. It detects whether the pulse width of the pulse wave in the serial code exceeds a default value according to a frequency signal. If the detected pulse width exceeds the If the default value is set, the pulse wave is determined as the initial pulse wave. Take the NEC code as an example to illustrate the difference between the initial pulse width and the data pulse width. In the NEC code, the pulse width during the high level period of the initial pulse is 9 milliseconds, while the data pulse width is 0.56 milliseconds. Therefore, , when the pulse width of a pulse in the sequence code exceeds the data pulse width (0.56 milliseconds) a lot, it can be determined that the pulse is the initial pulse. In this embodiment, the default value is set to 2 Milliseconds, when the detection unit 510 detects that the pulse width of a pulse wave exceeds 2 milliseconds, the detection unit determines that the pulse wave is the initial pulse wave. After the detection unit 510 detects an initial pulse wave, it will generate A notification signal INIT_PS is used to notify the determination unit 520 and the decoding unit 530 .

The decision unit 520 is used to calculate the sampling period S_P of the decoding sequence code. When the decision unit 520 receives the notification signal INIT_PS from the detection unit 510, it starts to calculate the pulse width of the data pulse that appears behind the initial pulse. degrees, and take this pulse width as the sampling period S_P for decoding the sequence code data bits. Taking the NEC code as an example, when the decision unit 520 receives the notification signal INIT_PS, it starts to calculate the pulse width of a pulse wave in the sequence code, which means to calculate the high level period of the pulse wave. In the standard NEC code, the pulse wave width The width is 0.56 milliseconds, so the determining unit 520 calculates a sampling period value of 0.56 milliseconds. However, the infrared remote control command may be disturbed during the transmission process, causing the pulse wave of the remote control command sequence code to be deformed. At this time, the decision unit 520 can still calculate the deformed pulse width, and use the pulse width as As the sampling period S_P, therefore, the decision unit of the present invention can accurately calculate the actual pulse width of the received remote command sequence code, and use this pulse width as the sampling period for decoding.

The decoding unit 530 is used to decode the binary value contained in the sequence code. When the decoding unit 530 receives the notification signal INIT_PS from the detection unit, it decodes all the values with the sampling period S_P calculated by the determination unit. For the received serial code, in one embodiment, the decoding unit 530 detects the number of sampling periods passed by every interval between two pulses in the serial code according to the sampling period S_P, so as to identify its corresponding binary value, The decoding unit 530 can detect the number of sampling cycles elapsed between the falling edge of a data pulse and the rising edge of an adjacent pulse in the sequence code, or detect the rising edge of a data pulse to an adjacent pulse. The number of sampling cycles passed by the rising edge or falling edge of the wave is used to identify the binary value represented by each pulse wave in the sequence code. Please refer to the schematic diagram shown in Figure 4(a), which uses the data bits of the NEC code as an example for illustration. When the number of cycles is less than 2 sampling periods S_P, the pulse wave represents binary "0". On the other hand, as shown in Figure 4(b), when the detected result is greater than or equal to 2 sampling periods S_P, the pulse wave The wave represents a binary "1". In addition, the sampling period on which the decoding unit 530 is based is generated by the actual received pulse width. Therefore, no matter whether the serial code is deformed during transmission, the decoding unit 530 can still correctly decode the received pulse width. serial number.

FIG. 6 is a schematic diagram of a preferred embodiment of the decoding device of the present invention. In the decoding device 600, the detection unit 610 first detects the initial pulse wave of the sequence code, and when the detected pulse width exceeds a default value, then it is determined that the pulse wave is the initial pulse wave, and the notification signal INIT_PS is used to notify the decoding unit 630 and the decision unit 620 respectively, so as to start the decoding unit 830 to decode the sequence code, and make the decision unit 620 according to the sequence code The code and frequency signals generate a sampling period. The determination unit 620 includes a counter 621 and a latch 622. After the counter 621 receives the notification signal INIT_PS from the detection unit 610, it calculates the pulse width of the first data pulse after the initial pulse according to the frequency signal. That is to calculate the frequency number passed during the high level period of the data pulse, and provide the last calculated frequency number to the latch 622, and the latch 622 will latch the received frequency number as the sampling period S_P, and The sampling period S_P is output to the decoding unit 630, and the decoding unit 630 decodes the data pulse wave of the serial code according to the sampling period S_P. At the same time, the decoding unit 630 temporarily stores the bit value obtained by decoding the serial code in In the memory unit 640 , after decoding a sequence of codes, the memory unit 640 outputs a complete command value.

To sum up, the present invention utilizes the pulse width of the received serial code to generate a sampling period, and decodes the serial code according to the sampling period, thus solving the problem of decoding deformed serial codes.

Although the present invention has been disclosed in detail using the above-mentioned preferred embodiments, it is not intended to limit the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be determined by the claims.

Claims (12)

1. an interpretation method, for decoding one sequence code, this sequence code comprises at least one initial pulse wave and complex data pulse wave, it is characterized in that, this interpretation method comprises the following step:

Receive this sequence code;

Detect this initial pulse wave of this sequence code;

After detecting this initial pulse wave, it is a sample period with the pulse bandwidth of actual first the data pulse wave received; And

According to this sample period detect interval in this sequence code between every two pulse waves the sample period number of process, and according to this sample period number, decoding is carried out to those data pulse waves.

2. interpretation method as claimed in claim 1, is characterized in that, detect in the step of this initial pulse wave, detect this initial pulse wave system and the pulse bandwidth of one pulse wave and a default value are compared.

3. interpretation method as claimed in claim 2, is characterized in that, detect in the step of this initial pulse wave, when the pulse bandwidth of a pulse wave exceedes this default value, judge that this pulse wave is as this initial pulse wave.

4. interpretation method as claimed in claim 1, it is characterized in that, carry out in the step of decoding according to this sample period to those data pulse waves, when the interval of the data pulse wave adjacent with next of the data pulse wave in those complex data pulse waves is not more than one predetermined this sample period, produce one first place value; When the interval of the data pulse wave adjacent with next of the data pulse wave in those complex data pulse waves is greater than this predetermined this sample period, produce one second place value.

5. interpretation method as claimed in claim 4, it is characterized in that, institute's elapsed time between the rising edge of the falling edge being spaced apart this data pulse wave next adjacent data pulse wave to this of the data pulse wave that the data pulse wave in those complex data pulse waves is adjacent with next.

6. a code translator, for decoding one sequence code, this sequence code comprises at least one initial pulse wave and complex data pulse wave, it is characterized in that, this code translator includes:

One detecting unit, is used for detecting this initial pulse wave, to produce a notice signal;

One determining means, is used for determining a sample period according to the pulse bandwidth of this notice signal and actual first the data pulse wave received; And

One decoding unit, be used for according to this sample period detect interval in this sequence code between every two pulse waves the sample period number of process, and according to this sample period number, decoding is carried out to those data pulse waves.

7. code translator as claimed in claim 6, it is characterized in that, this detecting unit system detects this initial pulse wave according to a default value.

8. code translator as claimed in claim 7, it is characterized in that, when the pulse bandwidth of a pulse wave is greater than this default value, this detecting unit judges that this pulse wave is as this initial pulse wave.

9. code translator as claimed in claim 6, is characterized in that, when the interval of the data pulse wave adjacent with next of the data pulse wave in those complex data pulse waves is not more than one predetermined this sample period, and decoding unit generation one first place value; When the interval of the data pulse wave adjacent with next of the data pulse wave in those complex data pulse waves is greater than this predetermined this sample period, decoding unit produces one second place value.

10. code translator as claimed in claim 9, it is characterized in that, institute's elapsed time between the rising edge of the falling edge being spaced apart this data pulse wave next adjacent data pulse wave to this of the data pulse wave that the data pulse wave in those complex data pulse waves is adjacent with next.

11. code translators as claimed in claim 6, is characterized in that, more comprise:

One mnemon, in order to store the decoding data that this decoding unit exports.

12. code translators as claimed in claim 6, it is characterized in that, this determining means comprises:

One counter, in order to according to this notice signal and a frenquency signal, calculates the pulse bandwidth of this data pulse wave in those data pulse waves; And

One latch unit, the count value obtained in order to this counter of breech lock.