Infrared Light Communication Method Based on Mode Switching

Abstract

The present invention relates to the technical field of signal acquisition, and particularly to an infrared optical communication method based on mode switching. The present invention uses a time-driven wake-up system to determine the state in which the circuit should operate according to the received pulse width, that is, according to the pulse width and the count value, the infrared optical communication system is controlled to enter the first sleep mode, the second sleep mode, the first communication mode, the second communication mode, and the third communication mode. The power consumption of the infrared optical communication system is adjusted by an event-driven mode switching circuit, achieving the technical effect of significantly reducing the power consumption of the infrared optical communication system in the sleep state.

Description

Technical Field

[0001] The present invention relates to the technical field of signal acquisition, and particularly to an infrared optical communication method based on mode switching. Background Art

[0002] ‌Infrared optical communication‌ is a communication method that uses infrared rays to transmit information, mainly transmitting data, language, text, images and other information through infrared radiation. The wavelength range of infrared optical communication is mainly between 0.70μm and 1mm, and the commonly used communication band is the near-infrared region of 950nm; the basic working principle of infrared optical communication is to modulate binary signals into infrared optical signals for transmission. The transmitting end converts the baseband binary signals into infrared optical signals through an infrared transmitting tube, and the receiving end receives these optical signals through an infrared detector, converts them into electrical signals, and then restores them to the original binary digital signals through amplification, filtering and demodulation processing.

[0003] ‌The front-end circuit of infrared optical communication‌ mainly includes an infrared transmitting circuit and an infrared receiving circuit. The infrared transmitting circuit is an important part of the infrared communication system, and its main function is to generate and transmit infrared signals. The infrared receiving circuit is composed of an infrared receiving diode, a triode or a silicon photocell, and its main function is to convert the received infrared optical signals into electrical signals.

[0004] The existing front-end circuit of infrared optical communication cannot automatically enter the sleep state when not in communication, and requires external signal control. The system structure is complex and the power consumption is high. Such a circuit is likely to deplete the battery power in the sleep state when used in a battery management system, and cannot meet the requirements. Summary of the Invention

[0005] In view of this, the present invention proposes an infrared optical communication method based on mode switching, which can be used for infrared optical communication between battery management chips, form a communication network, and at the same time achieve the effects of reducing power consumption and having a simple structure.

[0006] In order to achieve the above object, an infrared optical communication method based on mode switching is provided. The infrared optical communication method based on mode switching uses an infrared optical communication system to implement infrared optical communication. The infrared optical communication system includes: a transimpedance amplifier circuit, a hysteresis comparator, an output pulse judgment circuit, and a mode switching circuit. After the infrared optical communication system is reset, it first enters the standby mode;

[0007] Then, after detecting the falling edge of the pulse signal output by the hysteresis comparator, the mode switching circuit judges the count value of the counter in the mode switching circuit. If the count value is greater than or equal to the first preset value, it enters the communication mode;

[0008] After entering the communication mode, when the output pulse judgment circuit receives that the pulse signal remains at a low level within a preset time and the count value is greater than or equal to a second preset value, the mode switching circuit controls the infrared optical communication system to return to the standby mode.

[0009] Preferably, the standby mode includes a first sleep mode and a second sleep mode. After the infrared optical communication system is reset, it first enters the first sleep mode. When the output pulse judgment circuit detects the rising edge of the pulse signal output by the hysteresis comparator, the mode switching circuit controls the infrared optical communication system to enter the second sleep mode. Then, after detecting the falling edge of the pulse signal output by the hysteresis comparator, the mode switching circuit judges the count value of the counter in the mode switching circuit. If the count value is less than the first preset value, the mode switching circuit controls the infrared optical communication system to return to the first sleep mode.

[0010] Preferably, the communication mode includes a first communication mode, a second communication mode, and a third communication mode. After detecting the falling edge of the pulse signal output by the hysteresis comparator, the mode switching circuit judges the count value of the counter in the mode switching circuit. If the count value is greater than or equal to the first preset value, it enters the first communication mode; when the infrared optical communication system is in the first communication mode, if the output pulse judgment circuit receives the rising edge of the pulse signal before the end of the first preset time interval, the mode switching circuit controls the infrared optical communication system to enter the third communication mode. If the output pulse judgment circuit does not receive the rising edge of the pulse signal before the end of the first preset time interval, after the first preset time interval elapses, the mode switching circuit controls the infrared optical communication system to enter the second communication mode; when the transimpedance amplifier circuit enters the third communication mode, the mode switching circuit will not control the infrared optical communication system to return to the first communication mode until the output pulse judgment circuit receives the falling edge of the pulse signal; when the transimpedance amplifier circuit enters the second communication mode, the mode switching circuit will not control the infrared optical communication system to enter the third communication mode until the output pulse judgment circuit receives the rising edge of the pulse signal and the count value is less than the second preset value.

[0011] Preferably, the infrared optical communication method based on mode switching further includes: if the output pulse judgment circuit receives that the pulse signal remains at a low level within a preset time and the count value is greater than or equal to the second preset value, the mode switching circuit controls the infrared optical communication system to return to the first sleep mode.

[0012] Preferably, the infrared optical communication system further includes an oscillator and a delay unit. In the first sleep mode, the oscillator is in a sleep state and the delay unit does not work. In the second sleep mode, the oscillator works and the delay unit does not work. In the first communication mode, the oscillator does not work and the delay unit works. In the second communication mode, the oscillator works and the delay unit holds. In the third communication mode, the oscillator does not work and the delay unit does not work.

[0013] Preferably, the oscillator is a relaxation oscillator, and the oscillator includes a plurality of transistors and a fixed capacitor for generating an oscillation signal.

[0014] Preferably, the oscillator specifically includes: a first transistor M1, a second transistor M2, a third transistor M3, a fourth transistor M4, a fifth transistor M5, a sixth transistor M6, a seventh transistor M7, an eighth transistor M8, a ninth transistor M9, a tenth transistor M10, an eleventh transistor M11, a twelfth transistor M12, a thirteenth transistor M13, a fourteenth transistor M14, a fifteenth transistor M15, a sixteenth transistor M16, a seventeenth transistor M17, an eighteenth transistor M18, and a nineteenth transistor M19. The first transistor M1 and the second transistor M2 constitute the input stage of the oscillator for receiving an external signal Vin and an internal signal. The third transistor M3 and the fourth transistor M4 constitute a feedback stage and form a positive feedback network together with a capacitor C. The fifth transistor M5 and the sixth transistor M6 constitute a bias circuit to provide an operating point for the oscillator. The sixth transistor M6 and the seventh transistor M7 constitute a differential pair, and the eighth transistor M8 and the ninth transistor M9 constitute another differential pair. The tenth transistor M10 and the eleventh transistor M11 constitute a current mirror to provide a bias current for the differential pair. The thirteenth transistor M13, the fourteenth transistor M14, the fifteenth transistor M15, the sixteenth transistor M16, the seventeenth transistor M17, the eighteenth transistor M18, and the nineteenth transistor M19 constitute an output stage for amplifying the oscillation signal and providing it to an output terminal Vout.

[0015] Preferably, the first preset value is 25, the second preset value is 17, and the first preset time interval is 160 ns.

[0016] The advantages and beneficial effects of the present invention are as follows:

[0017] The present invention adopts a time-driven wake-up system to determine the state in which the circuit should operate according to the received pulse width, and uses an event-driven mode switching circuit to adjust the power consumption of the infrared optical communication system, greatly reducing its power consumption in the sleep state. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the present invention or the prior art. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0019] Figure 1 Schematic diagram of the infrared optical communication system provided by the embodiment of the present invention;

[0020] Figure 2 State transition diagram of the infrared optical communication method based on mode switching provided by the embodiment of the present invention;

[0021] Figure 3 Circuit structure diagram of the oscillator provided by the embodiment of the present invention. Specific embodiments

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0023] As shown in the Figure 1 accompanying drawings, the infrared optical communication method based on mode switching uses an infrared optical communication system to implement infrared optical communication. The infrared optical communication system includes: a transimpedance amplifier (TIA) circuit, a hysteresis comparator, an output pulse judgment circuit, and a mode switching circuit.

[0024] The transimpedance amplifier circuit (Transimpedance Amplifier, i.e., TIA) is a circuit that converts the photocurrent generated by a photodiode (such as a photoelectric diode) into a voltage signal. The core of the TIA circuit is to convert the input current signal into a voltage signal. Its basic structure includes an operational amplifier and a feedback resistor. Sometimes, a feedback capacitor is also connected in parallel to improve the stability of the system. The gain of the TIA is defined as the output voltage divided by the input current. Therefore, the unit of gain is resistance; in an optical communication circuit, the TIA is often used to convert the weak current signal output by the photodiode into a voltage signal for subsequent amplification, filtering, and digital processing.

[0025] A hysteresis comparator, also known as a Schmitt Trigger, is a comparator circuit with hysteresis characteristics. It is characterized by having two different threshold voltages, one for triggering a high-level output and the other for triggering a low-level output. This characteristic enables the hysteresis comparator to provide a stable output when there is noise in the input signal, thereby enhancing the anti-interference ability of the circuit.

[0026] Among them, the transimpedance amplifier (TIA) circuit is connected to the hysteresis comparator, the hysteresis comparator is connected to the output pulse judgment circuit, the output pulse judgment circuit is connected to the mode switching circuit, and the mode switching circuit is connected to the transimpedance amplifier (TIA) circuit. The transimpedance amplifier (TIA) circuit converts the input current into a voltage signal and outputs it to the hysteresis comparator. The hysteresis comparator outputs a high-level signal or a low-level signal according to the signal output by the transimpedance amplifier (TIA) circuit. When the signal output by the hysteresis comparator is a low-level signal, both the output pulse judgment circuit and the mode switching circuit are in an off state, thereby realizing the low-power operation of the infrared communication system.

[0027] In addition, in this embodiment, the infrared optical communication system has a standby mode and a communication mode. Among them, the standby mode includes a first sleep mode and a second sleep mode, and the communication mode includes a first communication mode, a second communication mode, and a third communication mode.

[0028] As Figure 2 shown, the infrared optical communication method based on mode switching is specifically as follows: After the infrared optical communication system is reset, it first enters the first sleep mode. When the output pulse judgment circuit detects the rising edge of the pulse signal output by the hysteresis comparator, the mode switching circuit controls the infrared optical communication system to enter the second sleep mode. Then, after detecting the falling edge of the pulse signal output by the hysteresis comparator, the mode switching circuit judges the count value of the counter in the mode switching circuit. If the count value < 25, the mode switching circuit controls the infrared optical communication system to return to the first sleep mode (sleep mode 1), and the oscillator sleeps; if the count is ≥ 25, the mode switching circuit controls the infrared optical communication system to enter the first communication mode (communication mode 1).

[0029] When the transimpedance amplifier (TIA) circuit is in the first communication mode (Communication Mode 1), if the output pulse judgment circuit receives the rising edge of the pulse signal before the end of the first preset time interval, the mode switching circuit controls the infrared optical communication system to enter the third communication mode (Communication Mode 3); if the output pulse judgment circuit does not receive the rising edge of the pulse signal before the end of the first preset time interval, after the first preset time interval elapses, the mode switching circuit controls the infrared optical communication system to enter the second communication mode (Communication Mode 2).

[0030] When the transimpedance amplifier (TIA) circuit enters the third communication mode (Communication Mode 3), the mode switching circuit will not control the infrared optical communication system to return to the first communication mode (Communication Mode 1) until the output pulse judgment circuit receives the falling edge of the pulse signal.

[0031] When the transimpedance amplifier (TIA) circuit enters the second communication mode (Communication Mode 2), the mode switching circuit will not control the infrared optical communication system to enter the third communication mode (Communication Mode 3) until the output pulse judgment circuit receives the rising edge of the pulse signal and the count value < the second preset count value.

[0032] If the output pulse judgment circuit receives that the pulse signal remains low-level within the preset time and the count value ≥ the second preset count value, the mode switching circuit controls the infrared optical communication system to return to the first sleep mode (Sleep Mode 1).

[0033] Wherein, the infrared optical communication system further includes an oscillator and a delay unit. The first sleep mode is that the oscillator sleeps and the delay unit does not work. The second sleep mode is that the oscillator works and the delay unit does not work. The first communication mode is that the oscillator does not work and the delay unit works. The second communication mode is that the oscillator works and the delay unit holds. The third communication mode is that the oscillator does not work and the delay unit does not work.

[0034] By utilizing the sleep-wake detection working mode, mode switching can significantly reduce the power consumption of the infrared optical communication system.

[0035] ‌Appendix Figure 3 shows the circuit structure diagram of the oscillator. As shown in the appendix Figure 3 shown, the oscillator includes multiple transistors and a fixed capacitor, and is used to generate an oscillation signal.

[0036] Among them, the oscillator specifically includes: a first transistor (M1), a second transistor (M2), a third transistor (M3), a fourth transistor (M4), a fifth transistor (M5), a sixth transistor (M6), a seventh transistor (M7), an eighth transistor (M8), a ninth transistor (M9), a tenth transistor (M10), an eleventh transistor (M11), a twelfth transistor (M12), a thirteenth transistor (M13), a fourteenth transistor (M14), a fifteenth transistor (M15), a sixteenth transistor (M16), a seventeenth transistor (M17), an eighteenth transistor (M18), and a nineteenth transistor (M19); the first transistor (M1) and the second transistor (M2) form the input stage of the oscillator, which is used to receive an external signal Vin and an internal signal, and provide an initial condition when the oscillator is powered on to start oscillation; the third transistor (M3) and the fourth transistor (M4) form a feedback stage, and together with a capacitor C form a positive feedback network to maintain oscillation; the fifth transistor (M5) and the sixth transistor (M6) form a bias circuit to provide an operating point for the oscillator; the sixth transistor (M6) and the seventh transistor (M7) form a differential pair, the eighth transistor (M8) and the ninth transistor (M9) form another differential pair, and the two are cross-coupled through the twelfth transistor (M12). Among them, the differential pair formed by the eighth transistor (M8) and the ninth transistor (M9) is used to protect the oscillator from damage when an abnormality occurs in the circuit; the tenth transistor (M10) and the eleventh transistor (M11) form a current mirror to provide a bias current for the differential pair, and the thirteenth transistor (M13), fourteenth transistor (M14), fifteenth transistor (M15), sixteenth transistor (M16), seventeenth transistor (M17), eighteenth transistor (M18), and nineteenth transistor (M19) form an output stage, which is used to amplify the oscillation signal and provide it to the output terminal Vout;

[0037] Among them, the oscillator used is a relaxation oscillator, and the oscillation period is achieved through the charging and discharging of a capacitor. When Vout is high, the capacitor discharges. After being judged by a comparator, finally Vout outputs low, and then the capacitor is charged. When the capacitor voltage reaches Vref, the comparator flips and Vout outputs high; in this embodiment, the capacitor C is set to 50 fF, and then the charging current is 5 microamps. At this time, one of its charging slopes is 100 volts per microsecond. The transimpedance amplifier adjusts the bias current and compensation resistance of the transimpedance amplifier according to the working mode by the mode switching circuit.

[0038] Among them, the comparator is a low-power comparator.

[0039] Those skilled in the art should understand that the embodiments herein can be provided as a method, an apparatus (device), or a computer program product. Therefore, the present disclosure can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Including but not limited to RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cassette, tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery medium.

[0040] The present disclosure is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (devices), and computer program products according to the embodiments herein. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0041] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means for implementing the steps of the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0042] The above-described embodiments and / or implementation manners are only used to illustrate the preferred embodiments and / or implementation manners for implementing the technology of the present invention, and do not impose any formal restrictions on the implementation manners of the technology of the present invention. Any person skilled in the art, without departing from the scope of the technical means disclosed in the content of the present invention, may make some changes or modifications to other equivalent embodiments, but should still be regarded as the same technology or embodiment as the present invention. Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An infrared light communication method based on mode switching, wherein the infrared light communication method based on mode switching uses an infrared light communication system to realize infrared light communication, and the infrared light communication system comprises: A transimpedance amplifier circuit, a hysteresis comparator, an output pulse judgment circuit, and a mode switching circuit, characterized in that: after the infrared light communication system is reset, it first enters the standby mode; then, after detecting the falling edge of the pulse signal output by the hysteresis comparator, the mode switching circuit judges the count value of the counter in the mode switching circuit, and if the count value is greater than or equal to a first pre-designed value, it enters the communication mode; after entering the communication mode, if the output pulse judgment circuit receives that the pulse signal is continuously at a low level within a preset time and the count value is greater than or equal to a second pre-designed value, the mode switching circuit controls the infrared light communication system to return to the standby mode; The standby mode includes a first sleep mode and a second sleep mode. After the infrared light communication system is reset, it first enters the first sleep mode. When the output pulse judgment circuit detects the rising edge of the pulse signal output by the hysteresis comparator, the mode switching circuit controls the infrared light communication system to enter the second sleep mode. Then, after detecting the falling edge of the pulse signal output by the hysteresis comparator, the mode switching circuit judges the count value of the counter in the mode switching circuit. If the count value is less than the first pre-designed value, the mode switching circuit controls the infrared light communication system to return to the first sleep mode. The communication mode includes a first communication mode, a second communication mode and a third communication mode. After detecting the falling edge of the pulse signal output by the hysteresis comparator, the mode switching circuit judges the count value of the counter in the mode switching circuit. If the count value is greater than or equal to the first pre-designed value, the first communication mode is entered. When the infrared light communication system is In the first communication mode, if the output pulse judgment circuit receives the rising edge of the pulse signal before the end of the first preset time interval, the mode switching circuit controls the infrared light communication system to enter the third communication mode; if the output pulse judgment circuit does not receive the rising edge of the pulse signal before the end of the first preset time interval, the mode switching circuit controls the infrared light communication system to enter the second communication mode after the first preset time interval delay ends; when the transimpedance amplifier circuit enters the third communication mode, the mode switching circuit will control the infrared light communication system to return to the first communication mode until the output pulse judgment circuit receives the falling edge of the pulse signal; when the transimpedance amplifier circuit enters the second communication mode, the mode switching circuit will control the infrared light communication system to enter the third communication mode until the output pulse judgment circuit receives the rising edge of the pulse signal and the count value is less than the second pre-designed value; The infrared light communication system includes an oscillator and a delay device. The first sleep mode is that the oscillator is dormant and the delay device does not work. The second sleep mode is that the oscillator works and the delay device does not work. The first communication mode is that the oscillator does not work and the delay device works. The second communication mode is that the oscillator works and the delay device remains on. The third communication mode is that the oscillator does not work and the delay device does not work.

2. The infrared light communication method based on mode switching according to claim 1, characterized in that: The infrared light communication method based on mode switching also includes: if the output pulse judgment circuit receives that the pulse signal is continuously at a low level within a preset time and the count value is greater than or equal to the second pre-designed value, the mode switching circuit controls the infrared light communication system to return to the first sleep mode.

3. The infrared light communication method based on mode switching according to claim 1, characterized in that: The oscillator is a relaxation oscillator, which includes a plurality of transistors and a constant capacitor and is used to generate an oscillation signal.

4. The infrared light communication method based on mode switching according to claim 3, characterized in that: The oscillator specifically includes: a first transistor M1, a second transistor M2, a third transistor M3, a fourth transistor M4, a fifth transistor M5, a sixth transistor M6, a seventh transistor M7, an eighth transistor M8, a ninth transistor M9, a tenth transistor M10, an eleventh transistor M11, a twelfth transistor M12, a thirteenth transistor M13, a fourteenth transistor M14, a fifteenth transistor M15, a sixteenth transistor M16, a seventeenth transistor M17, an eighteenth transistor M18 and a nineteenth transistor M19; the first transistor M1 and the second transistor M2 constitute an input stage of the oscillator for receiving an external signal Vin and an internal signal; the third transistor M3 and the fourth transistor M4 constitute The fifth transistor M5 and the sixth transistor M6 form a bias circuit to provide an operating point for the oscillator; the sixth transistor M6 and the seventh transistor M7 form a differential pair, and the eighth transistor M8 and the ninth transistor M9 form another differential pair; the tenth transistor M10 and the eleventh transistor M11 form a current mirror to provide a bias current for the differential pair, and the thirteenth transistor M13, the fourteenth transistor M14, the fifteenth transistor M15, the sixteenth transistor M16, the seventeenth transistor M17, the eighteenth transistor M18 and the nineteenth transistor M19 form an output stage for amplifying the oscillation signal and providing it to the output terminal Vout.

5. The infrared light communication method based on mode switching according to claim 1, characterized in that: The first preset count value is 25, the second preset count value is 17, and the first preset time interval is 160ns.

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