Non-contact serial port communication system and Internet of Things equipment

Abstract

The invention discloses a non-contact serial port communication system and Internet of Things equipment. The non-contact serial port communication system comprises a control module and a communication module, the control module comprises a first light-emitting assembly. The communication module comprises a first photosensitive assembly, a first switch unit, a first driving unit, a second switch unit and a communication unit; the first photosensitive assembly is used for outputting a conduction signal to the first switch unit when receiving an optical signal which is output by the first light-emitting assembly and exceeds a first preset intensity; the first switch unit is used for outputting a corresponding electric signal to the communication unit according to whether the conduction signal is received or not so as to realize a function of transmitting data to the communication unit; the first driving unit is used for outputting a driving signal to the control end of the second switch unit when the first switch unit outputs a high level; therefore, the second switch unit conducts a path between the first power supply and the power supply end, and the path is continuously conducted for a preset duration, so that the first power supply continuously supplies power to the communication unit in the data transmission stage.

Description

Technical Field

[0001] The present invention relates to the technical field of Internet of Things, and in particular to a contactless serial communication system and Internet of Things equipment. Background Art

[0002] In the field of IoT, devices often interact with platforms through networks such as NB_IoT or 4G (CAT.1). However, the quality of mobile networks is limited by base station deployment and signal coverage, making it difficult to ensure stable network communication. To meet customer needs, devices must be able to flexibly select different operator networks or communication methods.

[0003] In addition, the communication components in IoT devices often face failure problems, such as expiration of tariffs, communication module failure or battery exhaustion. To solve these problems, designers usually integrate communication modules, SIM cards, batteries and other components into communication components, separate them from the main structure of the device, and use contact connections (such as connectors or gold fingers) for data transmission and power control. Although this method is convenient for replacing communication components and switching networks, in harsh environments, contact connections are easily affected by moisture, oxidation or corrosion, resulting in communication failures. Summary of the invention

[0004] The main purpose of the present invention is to provide a contactless serial communication system, which aims to solve the connection and communication problems between the communication component and the device body in the Internet of Things device.

[0005] To achieve the above object, the present invention provides a contactless serial communication system, which includes: a control module and a communication module; The control module includes a control unit and a first light-emitting component connected to each other; the first light-emitting component is used to emit light or turn off light according to a signal output by the control unit; The communication module includes: a first photosensitive component, a first switch unit, a first driving unit, a second switch unit and a communication unit; The first photosensitive component and the first switch unit are arranged in parallel between the first power supply and the ground potential; the second switch unit is arranged between the first power supply and the power supply terminal of the communication module; The first photosensitive component is connected to the control end of the first switch unit, and is used to output a conduction signal to the first switch unit when receiving a light signal output by the first light-emitting component that exceeds a first preset intensity; the first switch unit is connected to the data input end of the communication unit, and is used to output a corresponding electrical signal to the communication unit according to whether the conduction signal is received, so as to realize the function of transmitting data to the communication unit; specifically, the first switch unit is turned on when receiving the conduction signal, and outputs a high level to the data input end; The input end of the first driving unit is connected to the first switch unit, and the output end is connected to the control end of the second switch unit, and is used to output a driving signal to the control end of the second switch unit when the first switch unit outputs a high level; the second switch unit is used to turn on the path between the first power supply and the power supply end when receiving the driving signal, and continue to turn on for a preset time after the driving signal disappears, so that the first power supply continues to power the communication unit during the data transmission stage.

[0006] Optionally, the first switch unit includes: a first switch tube and a voltage divider circuit; The first end of the first switch tube is connected to the first power supply, the control end is connected to the first photosensitive component, and the second end is connected to the first end of the voltage divider circuit; The first end of the voltage divider circuit is connected to the input end of the first driving unit, the second end is grounded, and the output end is connected to the data input end of the communication unit; the voltage divider circuit is used to output a high level to the data input end when the first switch tube is turned on, otherwise it outputs a low level.

[0007] Optionally, the second switch unit includes: a second switch tube and a delay circuit; The first end of the second switch tube is connected to the first power supply, the second end is connected to the power supply end of the communication unit, and the control end is connected to the output end of the first driving unit; The delay circuit is arranged between the first end and the control end of the second switch tube, and is used to store electric energy when the second switch tube receives a driving signal and turns on; The delay circuit is also used to maintain the potential difference between the first end and the control end of the second switch tube greater than the set voltage difference value within a preset time period after the drive signal disappears, so that the second switch tube remains turned on within the preset time period.

[0008] Optionally, the delay circuit includes a first capacitor and a first resistor; The first capacitor and the first resistor are arranged in parallel between the first end and the control end of the second switch tube.

[0009] Optionally, the first driving unit includes: a second resistor and a third switch tube; The two ends of the second resistor are respectively connected to the control ends of the first switch unit and the third switch tube; the first end of the third switch tube is connected to the control end of the second switch unit, and the second end is grounded; The third switch tube is used to be turned on when the first switch unit outputs a high level, and pull down the potential of the control end of the second switch unit, so that the second switch unit turns on the path between the first power supply and the power supply end.

[0010] Optionally, the communication module further includes: An indicating unit, wherein the first end of the indicating unit is connected to the first end of the first switch tube, and the second end is grounded; the indicating unit is used to emit light using the electric energy of the first power supply when the first switch tube is turned on, so as to indicate that the communication module is in a data receiving state.

[0011] Optionally, the first photosensitive component includes a first photosensitive element and a third resistor arranged in series; The first end of the third resistor is connected to the first power supply, the second end of the first photosensitive element is grounded; the first end of the first photosensitive element is connected to the control end of the first switch unit.

[0012] Optionally, the communication module further includes: a second light emitting component and a second driving unit; The second light-emitting component and the second driving unit are arranged in series between the power supply terminal of the communication unit and the ground potential; the control terminal of the second driving unit is connected to the data output terminal of the communication unit; The second driving unit is used to be turned on when the communication unit outputs the first electrical signal, so as to make the second light-emitting component emit light; The second driving unit is further used to shut down when the communication unit outputs the second electrical signal, so as to turn off the second light-emitting component; The control module further comprises a second photosensitive component, and the second photosensitive component is connected to the data input terminal of the control unit; The second photosensitive component is used to receive the light emitted by the second light-emitting component, and convert the on and off changes of the second light-emitting component into corresponding electrical signals and output them to the control unit.

[0013] Optionally, the second light-emitting component includes a fourth resistor and a second infrared emitting tube; the second driving unit includes a fourth switch tube; The fourth resistor is arranged between the power supply end of the communication unit and the anode of the second infrared emitting tube; the first end and the second end of the fourth switch tube are respectively connected to the cathode of the second infrared emitting tube and the ground potential; the control end of the fourth switch tube is connected to the data output end of the communication unit.

[0014] The second photosensitive component includes: a fifth resistor, a fifth switch tube, a second infrared receiving tube and a sixth resistor; The fifth resistor and the second infrared receiving tube are arranged in series between the second power supply and the ground potential; the fifth switch tube and the sixth resistor are arranged in series between the second power supply and the ground potential; The control end of the fifth switch tube is connected to the interconnected end of the fifth resistor and the second infrared receiving tube; the data input end of the control unit is connected to the interconnected end of the fifth switch tube and the sixth resistor.

[0015] The present invention also provides an Internet of Things device, which includes the contactless serial port communication system.

[0016] The present invention discloses a contactless serial communication system, which comprises: a control module and a communication module; the control module comprises a control unit and a first light-emitting component connected to each other; the first light-emitting component is used to emit light or turn off light according to a signal output by the control unit; the communication module comprises: a first photosensitive component, a first switch unit, a first drive unit, a second switch unit and a communication unit; the first photosensitive component and the first switch unit are arranged in parallel between a first power supply and a ground potential; the second switch unit is arranged between the first power supply and a power supply end of the communication module; the first photosensitive component is connected to a control end of the first switch unit, and is used to output to the first switch unit when receiving an optical signal output by the first light-emitting component that exceeds a first preset intensity. A conduction signal; the first switch unit is connected to the data input end of the communication unit, and is used to output a corresponding electrical signal to the communication unit according to whether the conduction signal is received, so as to realize the function of transmitting data to the communication unit; specifically, the first switch unit is turned on when the conduction signal is received, and outputs a high level to the data input end; the input end of the first drive unit is connected to the first switch unit, and the output end is connected to the control end of the second switch unit, and is used to output a drive signal to the control end of the second switch unit when the first switch unit outputs a high level; the second switch unit is used to conduct the path between the first power supply and the power supply end when the drive signal is received, and continue to conduct for a preset time after the drive signal disappears, so that the first power supply continues to power the communication unit during the data transmission stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 A first structural schematic diagram of a first embodiment of a contactless serial communication system of the present invention; Figure 2 A second structural schematic diagram of the first embodiment of the contactless serial communication system of the present invention; Figure 3 A third structural schematic diagram of the first embodiment of the contactless serial communication system of the present invention; Figure 4 A fourth structural diagram of the first embodiment of the contactless serial communication system of the present invention; Figure 5 A fifth structural diagram of the first embodiment of the contactless serial communication system of the present invention; Figure 6 A sixth structural diagram of the first embodiment of the contactless serial communication system of the present invention; Figure 7 It is a first structural schematic diagram of the second embodiment of the contactless serial communication system of the present invention; Figure 8 A second structural schematic diagram of the second embodiment of the contactless serial communication system of the present invention; Fig. 9 A third structural schematic diagram of the second embodiment of the contactless serial communication system of the present invention; Fig.10 It is a first structural schematic diagram of the third embodiment of the contactless serial communication system of the present invention; Fig.11 It is a second structural schematic diagram of the third embodiment of the contactless serial communication system of the present invention.

[0019] Description of Figure Numbers:

[0020] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] In the field of IoT, devices often interact with platforms through networks such as NB_IoT or 4G (CAT.1). However, the quality of mobile networks is limited by base station deployment and signal coverage, making it difficult to ensure stable network communication. To meet customer needs, devices must be able to flexibly select different operator networks or communication methods.

[0026] Due to the uneven coverage of mobile networks, the online rate of IoT instruments, especially IoT water meters, is generally not ideal. For example, in some places where the mobile signal is better than the telecom signal, mobile meters are installed on site. In some places, the telecom signal is better, but mobile water meters are installed; in some places, NB_IOT water meters are installed, but the surrounding NB_IoT network coverage is poor and the 4G network coverage is good, while in some places, NB_IoT network coverage is better than 4G network. This has caused the online rate of water meters purchased by water companies to generally fail to meet expectations after installation. In order to solve this problem, network optimization or replacement of water meters that are more compatible with the network environment is usually performed, which generates a lot of maintenance work. If there is a water meter that can directly replace the communication part without moving the main body of the water meter, and adaptive plug-and-play, it will greatly reduce the cost and efficiency problems caused by replacing water meters.

[0027] In order to achieve the above functions, it is necessary to design a structure in which the communication part and the main body of the instrument can be separated. In this way, the main body of the instrument can choose to connect to the communication unit that supports different operator networks, and send the communication command and data interaction when communication is needed. However, due to the use of some instruments, such as water meters, some of the use environments are very harsh, and the overall waterproof performance of the instrument is very high. This requires that the electrical connection between the main body of the instrument and the communication part must have a high waterproof performance in order to be durable and reliable. The traditional electrical connection between the communication module and the instrument mainboard is a UART interface, which requires at least several wires to be physically connected. This physical connection is difficult to implement in structural design, and the effect is often not as expected. If the physical connection serial port level communication is changed to optical signal communication, such as infrared communication, between the mainboard and the communication module through circuit conversion, the waterproof problem of this interface design can be effectively solved.

[0028] In addition, the communication components in IoT devices often face failure problems, such as expiration of tariffs, communication module failure or battery exhaustion. To solve these problems, designers usually integrate communication modules, SIM cards, batteries and other components into communication components, separate them from the main structure of the device, and perform data transmission and power control through contact connections (such as connectors or gold fingers). Although this method is convenient for replacing communication components and switching networks, in harsh environments, contact connections are prone to moisture, oxidation or corrosion, resulting in communication failures. In order to solve the above problems, this solution proposes a contactless serial communication system, specifically, using light as the communication carrier between the communication component and the main module.

[0029] It should be noted that serial communication is divided into simplex communication, half-duplex communication and full-duplex communication. The above three communication methods are suitable for different IoT scenarios; among them, simplex communication is suitable for scenarios where IoT devices report data information to the server, such as: IoT water meters that detect water flow, electricity meters that detect electricity consumption, or gas meters that detect gas consumption. Simplex and full-duplex communication are suitable for IoT scenarios that do not require high data timeliness; for example: shared bicycles report location information to the server, and the server transmits the current time information to the shared bicycle, as well as whether the vehicle is out of the operating range. Full-duplex communication is suitable for IoT scenarios that require high data timeliness, such as: unmanned automatic operation vehicles, robots, drones, or remote surgical medical equipment.

[0030] It is easy to understand that duplex communication can meet the needs of simplex communication scenarios and half-duplex communication scenarios, and half-duplex communication can meet the needs of simplex communication scenarios. For cost considerations, it is necessary to use corresponding serial communication technologies according to different IoT scenarios.

[0031] Reference Figures 1 to 6, a first embodiment of the present invention is proposed; the present invention discloses a contactless serial communication system, the contactless serial communication system comprising: a control module 1 and a communication module 2; The control module 1 includes a control unit 10 and a first light-emitting component 11 connected to each other; the first light-emitting component 11 is used to emit light or turn off light according to a signal output by the control unit 10; The communication module 2 includes: a first photosensitive component 20, a first switch unit 21, a first driving unit 22, a second switch unit 23 and a communication unit 24; The first photosensitive component 20 and the first switch unit 21 are arranged in parallel between the first power supply and the ground potential; the second switch unit 23 is arranged between the first power supply and the power supply end of the communication module 2; The first photosensitive component 20 is connected to the control end of the first switch unit 21, and is used to output a conduction signal to the first switch unit 21 when receiving a light signal output by the first light-emitting component 11 exceeding a first preset intensity; the first switch unit 21 is connected to the data input end of the communication unit 24, and is used to output a corresponding electrical signal to the communication unit 24 according to whether the conduction signal is received, so as to realize the function of transmitting data to the communication unit 24; specifically, the first switch unit 21 is turned on when receiving the conduction signal, and outputs a high level to the data input end; The input end of the first driving unit 22 is connected to the first switch unit 21, and the output end is connected to the control end of the second switch unit 23, and is used to output a driving signal to the control end of the second switch unit 23 when the first switch unit 21 outputs a high level; the second switch unit 23 is used to conduct the path between the first power supply and the power supply end when receiving the driving signal, and continue to conduct for a preset time after the driving signal disappears, so that the first power supply continues to supply power to the communication unit 24 during the data transmission stage. The communication unit 24 may include a WiFi module, a Bluetooth module, a StarFlash module or a ZigBee module, etc.

[0032] It should be noted that the contactless serial communication system is applied to IoT devices, and the control module 1 and the communication module 2 are components of the IoT devices. The communication module 2 is used to communicate with the server, and the control module 1 and the communication module 2 perform contactless serial communication; the communication method between the two may depend on the type of the IoT device and the timeliness requirements of the communication data with the server. In particular, the contactless serial communication system is applied to water meters, and the main function of the water meter is to upload the detected flow information to the server; therefore, the water meter can choose to use simplex communication, and the control module 1 transmits data to the communication module 2, and uploads data to the server through the communication module 2.

[0033] The control module 1 includes a control unit 10 and a first light-emitting component 11 connected to each other; the first light-emitting component 11 is used to emit light or turn off light according to the signal output by the control unit 10; the control module 1 controls the first light-emitting component 11 to emit light, so as to form high and low levels in the first photosensitive component 20 by emitting light and stopping emitting light, thereby transmitting signals. It is easy to understand that the first photosensitive component 20 includes a photosensitive device, which can adjust the electrical signal output to the first switch unit 21 signal according to the received light intensity; the first light-emitting component 11 can limit the wavelength of the light. As long as it can emit light and adjust the output voltage value according to the received light intensity. In particular, an infrared pair of tubes can be used, the infrared transmitting tube is arranged in the first light-emitting component 11, and the infrared receiving tube is arranged in the first photosensitive component 20. The control unit 10 may include a controller such as MCU, FPGA or SOC.

[0034] In order to avoid light interference inside and outside the IoT device, a closed space can be set in the IoT device, or the photosensitive element in the first photosensitive component 20 and the light-emitting element in the first light-emitting component 11 can be encapsulated.

[0035] The converted non-contact optical communication interface can realize the serial communication function between the control module and the communication module, but it also creates a new problem: the communication module needs to be powered independently and work in PSM or sleep mode, so that when the control module needs to communicate, the communication module can be woken up in time to complete the communication task. If the independently powered communication module works in PSW or sleep mode, theoretically there will still be power consumption.

[0036] Based on this, the present invention provides a circuit topology of a communication module, which can start and maintain the power supply of the communication module while the control module initiates a communication command, that is, initiates optical communication. After completing the communication task, the power supply of the communication module is automatically turned off, thereby further reducing the power consumption of the communication part.

[0037] The first photosensitive component 20 and the first switch unit 21 are arranged in parallel between the first power supply and the ground potential; the second switch unit 23 is arranged between the first power supply and the power supply end of the communication module 2; The first photosensitive component 20 is connected to the control end of the first switch unit 21 and is used to output a conduction signal to the first switch unit 21 when receiving a light signal output by the first light-emitting component 11 that exceeds a first preset intensity.

[0038] The first photosensitive component 20 is arranged between the first power supply and the low potential, and has a first photosensitive element. The first photosensitive element and other elements in the first photosensitive component 20 form a voltage divider circuit 210; the first photosensitive element adjusts its own resistance according to the received light intensity, thereby adjusting the voltage value at both ends of the first photosensitive component 20 and the voltage value loaded on the other elements. The first photosensitive component 20 can use the first photosensitive element, or the voltage value on the other elements as a conduction signal output to the control end of the first switch unit 21. It should be noted that due to the existence of the first power supply, the elements in the first photosensitive component 20 all have voltage, that is, the first photosensitive component 20 outputs an electrical signal to the first switch unit 21 when the first power supply works normally; however, for the first switch unit 21, a voltage signal to a current signal of a specific amplitude needs to be applied to the control end to be able to conduct, and at this time, the signal output by the first photosensitive component 20 is called a conduction signal.

[0039] That is, the specific value of the first preset intensity light signal can be obtained according to actual needs by the on-state voltage or current value of the first switch unit 21, the placement of the first photosensitive element in the first photosensitive component 20, and the characteristics of the first photosensitive element. Figure 1 In a specific implementation, the first photosensitive element is arranged near the first power supply, and the element near the ground potential in the first photosensitive component 20 is equivalent to the equivalent resistor in the figure, and the voltage value across the equivalent resistor is output to the first switch unit 21. As the light intensity increases, the resistance value of the first photosensitive element decreases, and the overcurrent capacity increases; the voltage value across the equivalent resistor increases; the first photosensitive component 20 outputs a high level to the first switch unit 21. It is easy to understand that in this embodiment, the first switch unit 21 needs to be turned on when receiving a high-level control signal; for example: NMOS tube.

[0040] Reference Figure 2 , the first photosensitive element is set close to the low potential, the element close to the first power supply in the first photosensitive component 20 is equivalent to the equivalent resistor in the figure, and the voltage across the first photosensitive element is output to the first switch unit 21. As the light intensity increases, the resistance value of the first photosensitive element decreases, and the voltage value across the two ends decreases; the first photosensitive component 20 outputs a low level to the first switch unit 21. It is easy to understand that in this embodiment, the first switch unit 21 needs to be turned on when receiving a low-level control signal. For example: PMOS tube.

[0041] Reference Figure 5The first photosensitive component 20 and the first switch component are arranged in parallel between the first power supply and the ground potential, and the second switch unit 23 is arranged between the first power supply and the communication unit 24; wherein, the first photosensitive component 20 outputs a signal to the first switch unit 21 and the second switch unit 23 according to the light intensity of the light emitted by the first light-emitting component 11, so as to control the first switch unit 21 and the second switch unit 23 to be turned on or off. Specifically, when the first photosensitive component 20 receives the light signal of the first preset intensity, it outputs a conduction signal to the first switch unit 21 and the second switch unit 23, so that the first switch unit 21 and the second switch unit 23 are turned on, so that the first power supply supplies power to the communication unit 24, and the first switch unit 21 outputs an electrical signal to transmit data information to the communication unit 24.

[0042] In addition, it is worth noting that the first switch unit 21 includes at least one switch device. In order to ensure that the electrical signal output to the communication unit 24 can change when the first switch unit 21 is turned on and off, the data input terminal of the communication unit 24 cannot be connected to the first power supply or low potential. Figure 3 , the voltage value across the equivalent resistance formed by the other components of the first switch unit 21 is used as the voltage signal output to the data input terminal of the communication unit 24. When the switch device is turned off, the data input terminal is at a low level; when the switch device is turned on, the data input terminal is at a high level. Figure 4 , the switch device is close to the ground potential. When the switch device is turned off, the data input terminal is at a high level; when the switch device is turned on, the data input terminal is at a low level.

[0043] In summary, it is easy to obtain that the placement position of the switch device in the first switch unit 21 and the placement position of the photosensitive element in the first photosensitive component 20 will affect the level signal received by the data input end of the communication unit 24 when the first light-emitting component 11 emits light. By reasonably setting the position of the switch device and the placement position of the photosensitive element, it can be achieved that when the first light-emitting component 11 emits a light signal exceeding the first preset intensity, the communication unit 24 receives a high-level signal. It is understandable that it is also possible to set the position of the switch device and the placement position of the photosensitive element separately to achieve that when the first light-emitting component 11 emits a light signal exceeding the first preset intensity, the communication unit 24 receives a low-level signal.

[0044] It should be noted that, under normal working conditions, the light intensity of the light signal emitted by the first light-emitting component 11 exceeds the first preset intensity. The first preset intensity can be used to filter out ambient light interference from the outside world that is lower than the first preset intensity; the first preset intensity can be determined by R&D personnel, and the corresponding switch device and the first photosensitive element can be selected.

[0045] When the first light-emitting component 11 emits light, the first photosensitive component 20 outputs a conduction signal to the first switch unit 21; when the first switch unit 21 receives the conduction signal, it outputs a high level or a low level to the data input terminal of the communication unit 24 according to the placement position of the switch device in the first switch unit 21. Correspondingly, when the first light-emitting component 11 does not emit light, the first switch unit 21 does not receive the conduction signal, and outputs a low level or a high level to the data input terminal. The control unit 10 can control the first light-emitting component 11 to emit light or turn off, and output a data signal to the communication unit 24 for communication, thereby realizing the function of transmitting data to the communication unit 24. In a specific implementation, Figure 3 As shown, the switch device is placed close to the first power supply; the first switch unit 21 is turned on when receiving a turn-on signal, and outputs a high level to the data input terminal. The first switch unit 21 is turned off when not receiving a turn-on signal, and outputs a low level to the data input terminal.

[0046] Reference Figure 5 and Figure 6 , the first photosensitive component 20 is connected to the first switch unit 21 and the second switch unit 23; when the first photosensitive component 20 receives the light signal emitted by the first light-emitting component 11, it outputs a conduction signal to the first switch unit 21 and the second switch unit 23; the second switch unit 23 is turned on when receiving the conduction signal, so that the first power supply supplies power to the communication unit 24. In combination with the light emission of the first light-emitting component 11, the first photosensitive component 20 outputs a conduction signal; if a capacitor is provided at the power supply end of the communication unit 24, when the second switch unit 23 receives the conduction signal and is turned on, the capacitor is charged; when the second switch unit 23 does not receive the conduction signal and is turned off, the capacitor continues to supply power to the communication unit 24. Thus, the control unit 10 can control the first power supply to supply power to the communication unit 24 through the output of the light signal by the first light-emitting component 11, and at the same time transmit data to the communication unit 24. It should be noted that this solution requires the communication unit 24 to cooperate with a capacitor with a suitable capacitance; the communication unit 24 on the market generally does not make corresponding settings, or the capacitance value may not meet the requirements. Therefore, the compatibility of this solution is not high. And it is easy for the first switch unit 21 to be damaged and lose its conducting capability, that is, when the data transmission function is damaged, the second switch unit 23 is turned on to wake up the communication unit 24 from the dormant state and wait for energy consumption.

[0047] In addition, since the second switch unit 23 is arranged in parallel between the first end and the output end of the first photosensitive component 20; Figure 6, an equivalent resistor is arranged between the source and gate of the MOS tube in the second switch unit 23; if the MOS tube in the figure is to be turned on when the first photosensitive component 20 stops outputting the conduction signal, so that the first power supply continues to supply power to the communication unit 24 during the signal transmission period. A capacitor is arranged between the gate and the source, and the capacitor and the equivalent resistor form an RC circuit. The continuous charging and discharging of the RC circuit will affect the voltage value of the conduction signal output by the first photosensitive component 20, and thus data transmission distortion occurs.

[0048] To solve the above problems, refer to Figure 7 , a second embodiment of the present invention is proposed. A first driving unit 22 is arranged between the first switch unit 21 and the second switch unit 23. The input end of the first driving unit 22 is connected to the first switch unit 21, and the output end is connected to the control end of the second switch unit 23, and is used to output a driving signal to the control end of the second switch unit 23 when the first switch unit 21 receives a conduction signal and is turned on; the second switch unit 23 is used to conduct the path between the first power supply and the power supply end when receiving the driving signal, and continue to conduct for a preset time after the driving signal disappears, so that the first power supply continues to power the communication unit 24 during the data transmission stage.

[0049] Reference Figure 3 and Figure 4 , the placement of the switch device inside the first switch unit 21 is different, which will affect the voltage amplitude of the output signal. Figure 8 In a specific implementation, when the first switch unit 21 outputs a high level, the first drive unit 22 outputs a drive signal to the control end of the second switch unit 23 so that the first power supply continues to power the communication unit 24 during the data transmission stage.

[0050] It should be noted that the output of the driving unit by the first driving unit 22 to the second switch unit 23 depends on the conduction of the first switch unit 21; therefore, it can be avoided that when the first switch unit 21 is damaged, the first power supply supplies power to the communication unit 24, thereby wasting electric energy. In addition, the second switch unit 23 is provided with a voltage-stabilizing freewheeling circuit such as an RC circuit, which will not cause the voltage value of the conduction signal output by the first photosensitive component 20 to change, thereby avoiding data transmission distortion.

[0051] In addition, the preset duration is determined by the R&D personnel, who can select and set the corresponding delay circuit 230 and related components according to actual needs to achieve the preset duration conduction.

[0052] The present invention discloses a contactless serial communication system, which comprises: a control module 1 and a communication module 2; the control module 1 comprises a control unit 10 and a first light-emitting component 11 connected to each other; the first light-emitting component 11 is used to emit light or turn off light according to a signal output by the control unit 10; the communication module 2 comprises: a first photosensitive component 20, a first switch unit 21, a first drive unit 22, a second switch unit 23 and a communication unit 24; the first photosensitive component 20 and the first switch unit 21 are arranged in parallel between a first power supply and a ground potential; the second switch unit 23 is arranged between the first power supply and a power supply end of the communication module 2; the first photosensitive component 20 is connected to a control end of the first switch unit 21, and is used to send a light signal to the first switch unit 23 when receiving a light signal output by the first light-emitting component 11 that exceeds a first preset intensity. The switch unit 21 outputs a conduction signal; the first switch unit 21 is connected to the data input end of the communication unit 24, and is used to output a corresponding electrical signal to the communication unit 24 according to whether the conduction signal is received, so as to realize the function of transmitting data to the communication unit 24; specifically, the first switch unit 21 is turned on when receiving the conduction signal, and outputs a high level to the data input end; the input end of the first drive unit 22 is connected to the first switch unit 21, and the output end is connected to the control end of the second switch unit 23, and is used to output a drive signal to the control end of the second switch unit 23 when the first switch unit 21 outputs a high level; the second switch unit 23 is used to conduct the path between the first power supply and the power supply end when receiving the drive signal, and continue to conduct for a preset time after the drive signal disappears, so that the first power supply continues to supply power to the communication unit 24 during the data transmission stage.

[0053] It should be noted that the present solution uses optical communication to communicate between the control module 1 and the communication module 2, replacing the traditional contact connection for data transmission, avoiding the disadvantages of the contact connection being susceptible to moisture, oxidation or corrosion, and providing a new contactless serial communication system. In addition, the present solution also provides a circuit structure of the communication module 2, which receives an optical signal through the first photosensitive component 20, provides a conduction signal to the first switch unit 21, and indirectly controls the conduction of the second switch unit 23; in particular, the second switch unit 23 is used to conduct the path between the first power supply and the power supply end when receiving a driving signal, and continues to conduct for a preset time after the driving signal disappears, so that the first power supply continues to supply power to the communication unit 24 during the data transmission stage. It is easy to understand that after the control module 1 initiates communication, the conduction signal emitted by the first photosensitive component 20 passes through the first switch component 21 and the first drive unit 22, causing the second switch unit 23 to conduct the path between the first power supply and the power supply end of the communication module 2, so that the first power supply supplies power to the communication unit 24; in addition, the first switch unit 21 is connected to the data input end of the communication unit 24, and is used to output a corresponding electrical signal to the communication unit 24 according to whether the conduction signal is received, thereby realizing the function of transmitting data to the communication unit 24; therefore, when the control module 1 initiates optical communication, the first power supply in the communication module 2 can supply power to the communication unit 24, and the first switch unit 21 sends an electrical signal corresponding to the optical signal received by the first photosensitive component 20 to the communication unit 24 by closing and conducting the switch, thereby completing data transmission.

[0054] In addition, the second switch unit 23 turns on the path between the first power supply and the power supply end when receiving a driving signal, and continues to turn on for a preset period of time after the driving signal disappears; thereby, when the optical communication data is continuously transmitted, the communication module 2 will not be frequently powered off due to the transmitted binary numbers, and after the optical communication is ended, the power supply of the communication unit 24 is disconnected in time to reduce the power consumption of the communication module 2.

[0055] The circuit provided by the present invention realizes the non-contact optical serial port communication function of the control module and the communication module, and at the same time, during the communication process, controls the effective supply of electric energy to the communication unit, thereby achieving comprehensive improvement in the waterproof performance, communication function and power consumption reduction of the communication components and the instrument theme, and providing a better separation solution of the main body and the communication.

[0056] The first switch unit 21 includes: a first switch tube Q1 and a voltage divider circuit 210; The first end of the first switch tube Q1 is connected to the first power supply, the control end is connected to the first photosensitive component 20, and the second end is connected to the first end of the voltage divider circuit 210; The first end of the voltage divider circuit 210 is connected to the input end of the first driving unit 22, the second end is grounded, and the output end is connected to the data input end of the communication unit 24; the voltage divider circuit 210 is used to output a high level to the data input end when the first switch tube Q1 is turned on, otherwise it outputs a low level.

[0057] The first switch tube Q1 is arranged close to the first power supply, and the voltage divider circuit 210 is arranged close to the ground potential; Figure 8 As shown, Figure 8 The resistor voltage divider circuit 210 is included. When the first switch tube Q1 is turned off, the voltage divider circuit 210 outputs a low level to the communication unit 24 and the first driving unit 22. Also, when the first switch tube Q1 is turned on, the voltage divider circuit 210 outputs a high level to the communication unit 24 and the first driving unit 22.

[0058] It is easy to see that the voltage divider circuit 210 outputs a high level to the communication unit 24 when the first light-emitting component 11 emits light; and the voltage divider circuit 210 outputs a low level to the communication unit 24 when the first light-emitting component 11 stops emitting light.

[0059] The first switch tube Q1 may include a triode, a MOS tube or an IGBT tube, etc. In particular, Figure 8 The first switch tube Q1 is a PMOS tube.

[0060] The second switch unit 23 includes: a second switch tube Q2 and a delay circuit 230; The first end of the second switch tube Q2 is connected to the first power supply, the second end is connected to the power supply end of the communication unit 24, and the control end is connected to the output end of the first driving unit 22; The delay circuit 230 is disposed between the first terminal and the control terminal of the second switch tube Q2, and is used to store electric energy when the second switch tube Q2 receives a driving signal and is turned on; The delay circuit 230 is also used to maintain the potential difference between the first end and the control end of the second switch tube Q2 greater than the set voltage difference value within a preset time period after the driving signal disappears, so that the second switch tube Q2 remains turned on within the preset time period.

[0061] It should be noted that the first light-emitting component 11 transmits data information through the on-off change of the light; the first photosensitive component 20 outputs a conduction signal to the first switch unit 21 and the second switch unit 23 when receiving the light to control the on and off of the first switch unit 21, thereby changing the voltage amplitude output to the communication unit 24, and then transmitting the data information. In addition, it is noted that the second switch unit 23 is turned on when receiving the driving signal, and maintains the second switch tube Q2 in the on state within a preset time. Combined with the details of the first light-emitting component 11 transmitting data through the on-off change of the light, in order to prevent the second switch tube Q2 from being turned off when the first light-emitting component 11 is off during the data transmission process, so that the communication unit 24 is powered off, resulting in data transmission failure. Therefore, it is necessary to set up a delay circuit 230, which is set between the first end and the control end of the second switch tube Q2, and is used to maintain the potential difference between the first end and the control end of the second switch tube Q2 greater than the set voltage difference value within a preset time after the driving signal disappears, so that the second switch tube Q2 remains turned on within the preset time; thereby avoiding the communication unit 24 from being powered off when the first light-emitting component 11 is extinguished.

[0062] In a specific implementation, the delay circuit 230 is an RC circuit. The RC circuit includes a first capacitor C1 and a first resistor R1. The first capacitor C1 and the first resistor R1 are arranged in parallel between the first end and the control end of the second switch tube Q2. The RC circuit stores electrical energy when the second switch tube Q2 receives a driving signal and turns on, and a potential difference is formed at both ends. After the driving signal disappears, due to the slow discharge of the RC circuit, the potential difference between the control end and the first end of the second switch tube Q2 slowly decreases, and the potential difference is greater than the set voltage difference value within a preset time length, so that the second switch tube Q2 remains turned on within a preset time length.

[0063] It is easy to understand that the set voltage difference value can be determined by the R&D personnel according to the specific model and performance of the selected second switch tube Q2. The second switch tube Q2 can be a MOS tube or an IGBT tube. In particular, the second switch tube Q2 is a PMOS tube.

[0064] The first driving unit 22 includes: a second resistor R2 and a third switch tube Q3; The two ends of the second resistor R2 are respectively connected to the first switch unit 21 and the control end of the third switch tube Q3; the first end of the third switch tube Q3 is connected to the control end of the second switch unit 23, and the second end is grounded; The third switch tube Q3 is used to be turned on when the first switch unit 21 outputs a high level, pulling down the potential of the control end of the second switch unit 23 so that the second switch unit 23 turns on the path between the first power supply and the power supply end.

[0065] The third switch tube Q3 may be a triode, a MOS tube or an IGBT tube, etc. In particular, the third switch tube Q3 is a triode.

[0066] In addition, in order to facilitate the inspection and maintenance process, it is determined whether the contactless serial communication system is working normally.

[0067] The communication module 2 also includes: The indicating unit 25 has a first end connected to the first end of the first switch tube Q1 and a second end connected to the ground. The indicating unit 25 is used to emit light using the first power supply energy when the first switch tube Q1 is turned on, so as to indicate that the communication module 2 is in a data receiving state.

[0068] The indicating unit 25 may include a light emitting diode (LED), a laser diode (LD) and an organic light emitting diode (OLED). It should be noted that the present solution does not limit the light emitting frequency, light emitting wavelength and light emitting brightness of the indicating unit 25 when emitting light.

[0069] In a specific implementation, the first photosensitive component 20 includes a first photosensitive element and a third resistor R3 arranged in series; A first end of the third resistor R3 is connected to the first power supply, a second end of the first photosensitive element is grounded; and a first end of the first photosensitive element is connected to a control end of the first switch unit 21 .

[0070] Since the second end of the first photosensitive component 20 is grounded, and the first end of the first photosensitive element is connected to the control end; when the first photosensitive element receives light and changes the current passing through, the voltage amplitude output to the control end changes. In particular, when the first photosensitive component 20 receives a light signal with a light intensity exceeding a first preset intensity, the first photosensitive component 20 outputs a low-level conduction signal to the first switch unit 21. The first photosensitive element may be a photodiode or a phototransistor.

[0071] The above embodiment discloses using the first light emitting component 11 and the first photosensitive component 20 to implement simplex communication between the control module 1 and the communication module 2. It is easy to understand that according to communication requirements in different scenarios, the control module 1 and the communication module 2 can also perform half-duplex communication or full-duplex communication.

[0072] Reference Fig.10 , a third embodiment of the present invention is proposed. The communication module 2 further includes: a second light emitting component 26 and a second driving unit 27; The second light emitting component 26 and the second driving unit 27 are arranged in series between the power supply terminal of the communication unit 24 and the ground potential; the control terminal of the second driving unit 27 is connected to the data output terminal of the communication unit 24; The second driving unit 27 is used to be turned on when the communication unit 24 outputs the first electrical signal, so that the second light-emitting component 26 emits light; The second driving unit 27 is further configured to be turned off when the communication unit 24 outputs a second electrical signal, so as to turn off the second light-emitting component 26 .

[0073] It should be noted that there are two types of positional relationships between the second light-emitting component 26 and the second driving unit 27, namely: the second light-emitting component 26 is arranged close to the power supply end of the communication unit 24, or the second driving unit 27 is arranged close to the communication unit 24. Because the power supply end of the communication unit 24 is connected to the first power supply through the second switch unit 23, the second light-emitting unit can only use the first power supply for energy after the second switch unit 23 is turned on.

[0074] When the second switch unit 23 is turned on, the second driving unit 27 turns on the path between the second light-emitting component 26 and the first power supply according to the electrical signal output by the communication unit 24, so that the second light-emitting component 26 uses the electrical energy provided by the first power supply to emit light. It is easy to understand that when the second switch unit 23 is turned on, the communication unit 24 resumes power supply and can control the second light-emitting component 26 to emit light or turn off by changing the electrical signal output to the second driving unit 27, thereby transmitting data information. The second light-emitting component 26 may include an LED, an OLED, or a light-emitting tube that emits light of a specific wavelength.

[0075] The control module 1 further comprises a second photosensitive component 12, and the second photosensitive component 12 is connected to a data input terminal of the control unit 10; The second photosensitive component 12 is used to receive the light emitted by the second light-emitting component 26, and convert the light-on and light-off changes of the second light-emitting component 26 into corresponding electrical signals and output them to the control unit 10. The second photosensitive component 12 may include a photosensitive device such as a photodiode or a phototransistor.

[0076] Reference Fig.10 In a specific implementation, the second light emitting component 26 includes a fourth resistor R4 and a second infrared emitting tube IET2; the second driving unit 27 includes a fourth switch tube Q4; The fourth resistor R4 is arranged between the power supply end of the communication unit 24 and the anode of the second infrared emitting tube IET2; the first end and the second end of the fourth switch tube Q4 are respectively connected to the cathode of the second infrared emitting tube IET2 and the ground potential; the control end of the fourth switch tube Q4 is connected to the data output end of the communication unit 24.

[0077] The second photosensitive component 12 includes: a fifth resistor R5, a fifth switch tube Q5, a second infrared receiving tube IRT2 and a sixth resistor R6; The fifth resistor R5 and the second infrared receiving tube IRT2 are connected in series between the second power supply and the ground potential; the fifth switch tube Q5 and the sixth resistor R6 are connected in series between the second power supply and the ground potential; The control end of the fifth switch tube Q5 is connected to the interconnected end of the fifth resistor R5 and the second infrared receiving tube IRT2; the data input end of the control unit 10 is connected to the interconnected end of the fifth switch tube Q5 and the sixth resistor R6.

[0078] When the fourth switch tube Q4 is turned on, the second infrared emitting tube IET2 emits light, and after the second infrared receiving tube IRT2 receives the light, the current flowing through the second infrared receiving tube IRT2 is increased to change the voltage amplitude output to the control end of the fifth switch tube Q5, thereby changing the potential at the data input end of the control unit 10.

[0079] It should be noted that the fifth resistor R5 and the second infrared receiving tube IRT2 are arranged in series between the second power supply and the ground potential, and there are two connection modes: the fifth resistor R5 is arranged close to the second power supply, and the second infrared receiving tube IRT2 is arranged close to the second power supply. This solution does not limit the specific arrangement of the fifth resistor R5 and the second infrared receiving tube IRT2 in the second photosensitive component 12.

[0080] Correspondingly, the fifth switch tube Q5 and the sixth resistor R6 are arranged in series between the second power supply and the ground potential, and there are two connection modes: the fifth switch tube Q5 is arranged close to the second power supply, and the sixth resistor R6 is arranged close to the second power supply. This solution does not limit the specific arrangement mode between the sixth resistor R6 and the fifth switch tube Q5.

[0081] It should be noted that the second photosensitive component 12 has four connection modes inside, and different connection modes may cause different voltage amplitudes output to the data input terminal of the control unit 10 when receiving the light emitted by the second light-emitting component 26. The above example of the connection mode between the first photosensitive component 20 and the first switch unit 21 affecting the output signal can be referred to.

[0082] It should be noted that the second infrared receiving tube IRT2 and the second infrared transmitting tube IET2 can be packaged to prevent interference from external light or light emitted by the first light-emitting component 11. The second power supply can be independent of the first power supply, or it can be converted from the first power supply. The fourth switch tube Q4 and the fifth switch tube Q5 may include MOS tubes, triodes or IGBT tubes. In particular, considering that the fourth switch tube Q4 is controlled to be turned on / off by the electrical signal output by the communication unit 24; the communication unit 24 includes a chip, and the chip is used to control the on / off of the fourth switch tube Q4; combined with the limited voltage output capability of the chip's I / O port, the fourth switch tube Q4 is a triode.

[0083] In this embodiment, there are the first light-emitting component 11, the first photosensitive component 20, the second light-emitting component 26 and the second photosensitive component 12, which meet the conditions of half-duplex communication and full-duplex communication; half-duplex communication or full-duplex communication can be realized.

[0084] Reference Fig.11 In a specific implementation, the second driving unit 27 further includes a tenth resistor R10, and the two ends of the tenth resistor R10 are respectively connected to the control end of the fourth switch tube Q4 and the data output end of the communication unit 24. In particular, the fourth switch tube Q4 is a triode, and the gate of the triode is connected to the tenth resistor R10.

[0085] The voltage divider circuit 210 includes an eighth resistor R8 and a ninth resistor R9 which are connected in series between the first switch tube Q1 and the ground potential; the first end of the eighth resistor R8 and the first end of the ninth resistor R9 are connected to the data input end of the communication unit 24. The first light-emitting component 11 includes a seventh resistor R7 and a first infrared emitting tube IET1, and the two ends of the seventh resistor R7 are connected to the control unit 10 and the anode of the first infrared emitting tube IET1 respectively.

[0086] The indicating unit 25 includes an eleventh resistor R11 and a light emitting element. The eleventh resistor R11 and the light emitting element are connected in series between the first switch tube Q1 and the ground potential. In particular, the light emitting element is an LED lamp.

[0087] The first switch tube Q1 , the second switch tube Q2 and the fifth switch tube Q5 are PMOS tubes, and the third switch tube Q3 and the fourth switch tube Q4 are triodes.

[0088] It should be noted that the MOS tube and triode in the drawings are a form of expression of each switch tube, and it does not mean that only the specific switch devices shown in the drawings can be used. In addition, the first infrared transmitting tube IET1, the second infrared transmitting tube IET2, the first infrared receiving tube IRT1 and the second infrared receiving tube IRT2 in the drawings are only an optional embodiment of the present invention, and do not limit the selection of light-emitting elements and photosensitive elements.

[0089] In addition, it can be known from the above contents in the specification that the arrangement of the components in the second photosensitive component 12, the first photosensitive component 20 and the first switch unit 21 shown in the drawings is only an optional embodiment and does not limit other arrangement methods.

[0090] The present invention also proposes an Internet of Things device, which includes the contactless serial port communication system. The specific structure of the contactless serial port communication system refers to the above embodiment. Since the Internet of Things device adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0091] In a specific implementation, the Internet of Things device may be a smart water meter.

[0092] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A contactless serial communication system, characterized in that: The contactless serial communication system comprises: a control module and a communication module; The control module includes a control unit and a first light-emitting component connected to each other; the first light-emitting component is used to emit light or turn off light according to a signal output by the control unit; The communication module includes: a first photosensitive component, a first switch unit, a first driving unit, a second switch unit and a communication unit; The first photosensitive component and the first switch unit are arranged in parallel between the first power supply and the ground potential; the second switch unit is arranged between the first power supply and the power supply terminal of the communication module; The first photosensitive component is connected to the control end of the first switch unit, and is used to output a conduction signal to the first switch unit when receiving a light signal output by the first light-emitting component that exceeds a first preset intensity; the first switch unit is connected to the data input end of the communication unit, and is used to output a corresponding electrical signal to the communication unit according to whether the conduction signal is received, so as to realize the function of transmitting data to the communication unit; specifically, the first switch unit is turned on when receiving the conduction signal, and outputs a high level to the data input end; The input end of the first driving unit is connected to the first switch unit, and the output end is connected to the control end of the second switch unit, and is used to output a driving signal to the control end of the second switch unit when the first switch unit outputs a high level; the second switch unit is used to turn on the path between the first power supply and the power supply end when receiving the driving signal, and continue to turn on for a preset time after the driving signal disappears, so that the first power supply continues to power the communication unit during the data transmission stage.

2. The contactless serial communication system according to claim 1, characterized in that: The first switch unit includes: a first switch tube and a voltage divider circuit; The first end of the first switch tube is connected to the first power supply, the control end is connected to the first photosensitive component, and the second end is connected to the first end of the voltage divider circuit; The first end of the voltage divider circuit is connected to the input end of the first driving unit, the second end is grounded, and the output end is connected to the data input end of the communication unit; the voltage divider circuit is used to output a high level to the data input end when the first switch tube is turned on, otherwise it outputs a low level.

3. The contactless serial communication system according to claim 1, characterized in that: The second switch unit includes: a second switch tube and a delay circuit; The first end of the second switch tube is connected to the first power supply, the second end is connected to the power supply end of the communication unit, and the control end is connected to the output end of the first driving unit; The delay circuit is arranged between the first end and the control end of the second switch tube, and is used to store electric energy when the second switch tube receives a driving signal and turns on; The delay circuit is also used to maintain the potential difference between the first end and the control end of the second switch tube greater than the set voltage difference value within a preset time period after the drive signal disappears, so that the second switch tube remains turned on within the preset time period.

4. The contactless serial communication system according to claim 3, characterized in that: The delay circuit includes a first capacitor and a first resistor; The first capacitor and the first resistor are arranged in parallel between the first end and the control end of the second switch tube.

5. The contactless serial communication system according to claim 1, characterized in that: The first driving unit includes: a second resistor and a third switch tube; The two ends of the second resistor are respectively connected to the control ends of the first switch unit and the third switch tube; the first end of the third switch tube is connected to the control end of the second switch unit, and the second end is grounded; The third switch tube is used to be turned on when the first switch unit outputs a high level, and pull down the potential of the control end of the second switch unit, so that the second switch unit turns on the path between the first power supply and the power supply end.

6. The contactless serial communication system according to claim 2, characterized in that: The communication module also includes: An indicating unit, wherein the first end of the indicating unit is connected to the first end of the first switch tube, and the second end is grounded; the indicating unit is used to emit light using the electric energy of the first power supply when the first switch tube is turned on, so as to indicate that the communication module is in a data receiving state.

7. The contactless serial communication system according to any one of claims 1 to 6, characterized in that: The first photosensitive component includes a first photosensitive element and a third resistor arranged in series; The first end of the third resistor is connected to the first power supply, the second end of the first photosensitive element is grounded; the first end of the first photosensitive element is connected to the control end of the first switch unit.

8. The contactless serial communication system according to claim 7, characterized in that: The communication module further includes: a second light emitting component and a second driving unit; The second light-emitting component and the second driving unit are arranged in series between the power supply terminal of the communication unit and the ground potential; the control terminal of the second driving unit is connected to the data output terminal of the communication unit; The second driving unit is used to be turned on when the communication unit outputs the first electrical signal, so as to make the second light-emitting component emit light; The second driving unit is further used to shut down when the communication unit outputs the second electrical signal, so as to turn off the second light-emitting component; The control module further comprises a second photosensitive component, and the second photosensitive component is connected to the data input terminal of the control unit; The second photosensitive component is used to receive the light emitted by the second light-emitting component, and convert the on and off changes of the second light-emitting component into corresponding electrical signals and output them to the control unit.

9. The contactless serial communication system according to claim 8, characterized in that: The second light emitting component includes a fourth resistor and a second infrared emitting tube; the second driving unit includes a fourth switch tube; The fourth resistor is arranged between the power supply terminal of the communication unit and the anode of the second infrared emitting tube; the first end and the second end of the fourth switch tube are respectively connected to the cathode of the second infrared emitting tube and the ground potential; the control end of the fourth switch tube is connected to the data output end of the communication unit; The second photosensitive component includes: a fifth resistor, a fifth switch tube, a second infrared receiving tube and a sixth resistor; The fifth resistor and the second infrared receiving tube are arranged in series between the second power supply and the ground potential; the fifth switch tube and the sixth resistor are arranged in series between the second power supply and the ground potential; The control end of the fifth switch tube is connected to the interconnected end of the fifth resistor and the second infrared receiving tube; the data input end of the control unit is connected to the interconnected end of the fifth switch tube and the sixth resistor.

10. An Internet of Things device, characterized in that: The Internet of Things device includes the contactless serial communication system as described in any one of claims 1 to 9.

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