Passive communication module and method

Abstract

The invention discloses a passive communication module and method. The passive communication module comprises a LoRa transparent transmission module, a supercapacitor and a UART interface, the LoRa unvarnished transmission module is connected with the UART interface, the LoRa unvarnished transmission module is provided with a super capacitor, and when the LoRa unvarnished transmission module needs wireless communication, required electric energy is obtained from the super capacitor, so that wireless data transmission without an external power supply is realized. According to the invention, the RX / TX pin of the UART interface is creatively utilized to collect energy, and the super capacitor is adopted as energy storage equipment, so that extra power supply requirements are avoided, the equipment can be deployed in places which are difficult to touch or unchanged in wiring in the past, a real passive LoRa communication module is realized, and the LoRa communication module is suitable for various scenes without a power supply or difficult to acquire the power supply; the deployment flexibility is enhanced, and the application range of the LoRa technology in the Internet of Things equipment is expanded; the structure is relatively simple, and does not depend on the stability of an external power supply, and the passive module is higher in reliability and smaller in electromagnetic interference under a severe environment condition.

Description

Technical Field

[0001] The present invention relates to the technical field of Internet of Things, and in particular to a passive communication module and method. Background Art

[0002] In Internet of Things (IoT) applications, LoRa (Long Range) is an ideal choice for building IoT networks with wide coverage, low maintenance and high cost performance due to its unique technical characteristics such as long distance, low power consumption, large capacity and low cost. LoRa technology is usually implemented in IoT applications in the form of LoRa communication modules. LoRa modules are devices that integrate LoRa wireless communication technology on a small circuit board. They contain all the necessary components required to implement LoRa communication, such as radio frequency (RF) transceivers, antennas, microcontrollers, power management circuits, and possible interface circuits (such as UART, SPI or I2C).

[0003] In Internet of Things (IoT) applications, the most common LoRa communication module is an active module. An active LoRa module contains its own power source (such as a battery or power adapter) and can actively send and receive wireless signals to achieve long-distance, low-power communication. Features include: built-in power supply: Since the LoRa module contains its own power source, such as a battery or power adapter or other power source, it can actively generate and consume energy; communication capabilities: they can actively transmit and receive signals for two-way communication; functions: active modules usually have a microcontroller and memory, which can perform complex data processing and storage tasks; applicable scenarios: suitable for application scenarios that require long-distance communication, timed data transmission or complex data processing, such as remote sensor networks, asset tracking, smart cities, etc.

[0004] However, active LoRa communication modules may cause great inconvenience in some application scenarios, mainly in the following aspects:

[0005] 1. Application scenarios with limited space: (1) Wearable devices: such as smart watches, health monitoring bracelets, etc. These devices are usually required to be small and light. Built-in batteries will increase the size and weight, affecting wearing comfort. (2) Micro sensors: such as environmental monitoring, agricultural sensors, etc., need to be miniaturized to adapt to narrow or hidden installation locations. Built-in batteries will limit the miniaturization of devices.

[0006] 2. Locations where it is difficult to wire or replace batteries: (1) Applications in remote areas: For example, field environment monitoring, remote agricultural monitoring, etc. These devices may be located in remote areas, making it difficult to wire and replace batteries regularly. (2) High-altitude or underwater applications: For example, sensors on high towers, underwater monitoring equipment, etc. Wiring and replacing batteries require special equipment or professionals, which is costly and inconvenient.

[0007] 3. Applications that require long periods of unattended operation: (1) Remote monitoring: Such as forest fire monitoring, wildlife tracking, etc. These devices may need to be unattended for a long time, and the life of the built-in battery is limited, so battery replacement needs to be considered. (2) Scientific research: Such as deep-sea probes, space probes, etc. Once deployed, these devices are difficult to recover or maintain, and battery life becomes a key factor.

[0008] 4. Cost-sensitive applications: (1) Large-scale deployment: For example, a large number of sensor nodes in a smart city project, the cost of each node will affect the overall cost of the project. (2) One-time or short-term applications: For example, temporary monitoring equipment during an event, cost is an important factor in deciding whether to use an active LoRa module.

[0009] Traditional passive modules usually do not have some monitoring mechanism for their power supply stability. This risk makes the communication of passive modules extremely unstable in the initial stage of module operation (for example, when the passive module is in the power storage stage).

[0010] In summary, active LoRa communication modules are widely used in Internet of Things (IoT) applications due to their unique technical characteristics. However, they will cause corresponding inconveniences in some application scenarios such as space constraints, difficulty in wiring or battery replacement, long-term unattended operation, and cost sensitivity. In order to alleviate the problems encountered in the above scenarios, it is necessary to improve the applicability and performance of the module. Summary of the invention

[0011] The present invention provides a passive communication module and method, which effectively solves the problems of structural complexity, size, cost, inconvenience in application, etc. caused by the need for a built-in power supply for power supply of an active LoRa communication module.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] A passive communication module, including a LoRa transparent transmission module, a super capacitor, and a UART interface;

[0014] The LoRa transparent transmission module is connected to the UART interface, and the LoRa transparent transmission module realizes the conversion of serial port data to LoRa wireless data through the UART interface, and the UART interface is used to exchange data with the user equipment;

[0015] The LoRa transparent transmission module is equipped with a supercapacitor for storing electric energy obtained from the UART interface. When the LoRa transparent transmission module needs to perform wireless communication, the required electric energy is obtained from the supercapacitor to realize wireless data transmission without an external power supply.

[0016] As a preferred embodiment of the above scheme, the LoRa transparent transmission module adopts the EasyLink LM401 module, which integrates a single-chip microcomputer, a LoRa communication module, a built-in crystal oscillator and multiple interfaces.

[0017] As a preferred embodiment of the above solution, the UART interface is connected to the user equipment through the RX pin and the TX pin, and obtains electrical energy through the RX and TX pins and stores it in a supercapacitor.

[0018] As a preferred embodiment of the above scheme, the supercapacitor is a farad capacitor.

[0019] As a preferred embodiment of the above solution, an isolation diode and a current limiting resistor are arranged between the supercapacitor and the UART interface.

[0020] As a preferred embodiment of the above scheme, it also includes an energy management unit, which is connected to the supercapacitor to manage the electric energy obtained from the UART interface and store it in the supercapacitor efficiently.

[0021] A passive communication method, comprising:

[0022] S1. Establish connection: The user device performs handshake protocol with the LoRa transparent transmission module through the UART interface;

[0023] S2, power-on initialization: When the LoRa module is connected to the device, the external device will input the power control to the TXR line to quickly charge the supercapacitor;

[0024] S3, supercapacitor charging: When the LoRa transparent transmission module is in idle state, the RXD and TXD pins of the UART interface of the user equipment are in a high level state, providing a pull-up voltage to charge the supercapacitor and store it in the supercapacitor;

[0025] S4, Energy confirmation: The user device initiates an energy confirmation request and sends an energy confirmation mechanism data frame through the UART interface. After receiving the energy confirmation request, the LoRa transparent transmission module checks whether the power of the supercapacitor is sufficient to support a complete wireless data transmission. If the power is sufficient, the LoRa transparent transmission module sends an energy confirmation response 5 times through the UART interface, indicating that it is ready for wireless data transmission; if the power is insufficient, the LoRa transparent transmission module does not respond and continues to charge until the power is sufficient;

[0026] S5. LoRa transparent transmission module works: When the energy confirmation response is successfully sent, the LoRa transparent transmission module can use the electrical energy stored in the supercapacitor for wireless data transmission when wireless communication is needed.

[0027] As a preferred embodiment of the above scheme, when the supercapacitor is charged, the voltage is transmitted to the supercapacitor through the current limiting resistor for charging, so as to prevent the charging current from being too large and protect the supercapacitor; at the same time, the diode prevents the voltage of the supercapacitor from flowing back into the UART interface, so as to maintain the normal working state of the UART interface.

[0028] Due to the above structure, the beneficial effects of the present invention are:

[0029] 1. Innovative use of the RX / TX pins of the UART interface for energy collection avoids the need for additional power. Without the need for external power constraints, the device can be deployed in places that were previously difficult to reach or where wiring remained unchanged, such as remote areas, on mobile objects or in embedded applications, realizing a truly passive LoRa communication module that is suitable for a variety of scenarios where there is no power supply or power supply is difficult to obtain, enhancing deployment flexibility and expanding the application scope of LoRa technology in IoT devices; at the same time, because the passive module does not have a built-in power supply and complex control circuit, its structure is relatively simple, which reduces the overall product structure, simplifies system design, and reduces equipment costs and failure rates; moreover, it does not rely on the stability of the external power supply, and the passive module has higher reliability and less electromagnetic interference (EMI) under harsh environmental conditions (such as voltage fluctuations, electromagnetic interference, etc.);

[0030] 2. Using supercapacitors as energy storage devices has the characteristics of fast charging and efficient discharge, that is, it has a mechanism for quickly replenishing electric energy (such as when the device is initialized or just powered on), which can meet the instantaneous high power consumption requirements of the LoRa module. It can also be charged when the UART interface is not working and use energy during LoRa communication, making full use of the idle time of the system;

[0031] 3. Through efficient energy management and utilization of the energy management unit, the passive LoRa module can remain operational for a longer period of time, and its lifespan may far exceed that of active devices;

[0032] 4. It provides an energy confirmation mechanism, which solves the problem that the traditional passive module may cause unstable power supply or abnormal communication when working passively, and ensures that communication is carried out under the condition of stable module power supply;

[0033] 5. When the traditional passive module is powered on, the charging current transmitted through the communication line is usually very small. The internal energy storage capacitor has the problem of slow charging. This design can achieve fast charging and add energy communication protocol to ensure the timeliness and stability of communication during the power-on stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0035] Figure 1 It is a structural schematic diagram of the present invention;

[0036] Figure 2 is a complete circuit diagram of the present invention;

[0037] Figure 3 This is the circuit diagram of the LoRa transparent transmission module of the present invention;

[0038] Figure 4 The interface circuit and energy circulation circuit design diagram of the present invention;

[0039] Figure 5 It is a schematic diagram of the UART energy supply and energy confirmation mechanism of the present invention;

[0040] Figure 6 It is a flow chart of the energy confirmation mechanism of the present invention;

[0041] Figure 7 It is a schematic diagram of the UART data format of the present invention;

[0042] Figure 8 Schematic diagram of the UART data question and answer mechanism of the present invention. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0044] like Figure 1 As shown, this embodiment provides a passive communication module, including a LoRa transparent transmission module, a supercapacitor, and a UART interface; the LoRa transparent transmission module is connected to the UART interface, and the LoRa transparent transmission module realizes the conversion of serial port data to LoRa wireless data through the UART interface, and the UART interface is used to exchange data with a user device; a supercapacitor is installed on the LoRa transparent transmission module to store the electric energy obtained from the UART interface, and when the LoRa transparent transmission module needs to perform wireless communication, the required electric energy is obtained from the supercapacitor to realize wireless data transmission without an external power supply.

[0045] In this embodiment, the LoRa transparent transmission module adopts the Easylink LM401 module, which integrates a single-chip microcomputer, a LoRa communication module, a built-in crystal oscillator and multiple interfaces. Among them, the single-chip microcomputer: adopts the STM32WLE5CBU6 single-chip microcomputer, which is based on the ARM Cortex-M4 core; built-in 128K flash, 48K SRAM, providing sufficient storage space and running memory. LoRa communication module: the communication core is SX1262, supporting LoRa modulation technology; supporting two modulation modes: LoRa (default) and FSK; the maximum transmission power is 22dBm, which is suitable for long-distance wireless communication. Working voltage: the rated working voltage is 1.8V to 3.6V, which is suitable for battery-powered application scenarios. Built-in crystal oscillator: built-in 32.768KHz crystal oscillator, providing a stable clock signal. Packaging and interface: 30Pin SMT packaging is adopted, which is convenient for installation and welding on the PCB board; multiple interfaces include UART, IIC, SPI and ADC, etc., which are convenient for connection and data exchange with external devices.

[0046] In this embodiment, the UART interface is connected to the user equipment through the RX (receive) pin and the TX (transmit) pin, and obtains electrical energy through the RX and TX pins and stores it in a supercapacitor. The supercapacitor is a farad capacitor. An isolation diode and a current limiting resistor are provided between the supercapacitor and the UART interface. The circuit diagram is shown in FIG. Figures 2 to 4 As shown, the key components are as follows:

[0047] (1) Supercapacitor (farad capacitor):

[0048] Voltage: 3.6V

[0049] ·Capacity: 1F

[0050] Style: C type

[0051] Brand: CDA, Taiwan, China

[0052] Function: As an energy storage element, it is used to store the power obtained from the UART interface.

[0053] (2) Current limiting resistor:

[0054] R31 and R32

[0055] Function: To adjust the charging current of the supercapacitor to prevent excessive charging current from damaging the supercapacitor.

[0056] (4) Isolation diode:

[0057] D1 and D2

[0058] Type: Low voltage drop Schottky diode

[0059] Function: Isolate the supercapacitor and UART interface to prevent the reverse voltage of the supercapacitor from affecting the normal operation of the UART interface.

[0060] (4)UART interface:

[0061] 1) TX_h and TX_s are UART data outputs:

[0062] TX_h and TX_s are the data output pins of UART.

[0063] TX_h indicates the output in the high level state, and TX_s indicates the serial output state.

[0064] These two pins are responsible for sending data to the single-wire UART communication line.

[0065] 2) RX_h and RX_s are UART data reception:

[0066] RX_h and RX_s are the data receiving pins of UART.

[0067] RX_h indicates reception in high level state, and RX_s indicates serial reception state.

[0068] These two pins are responsible for receiving data from the single-wire UART communication line.

[0069] 3) TX_h and TX_s pins must support two states: "serial output" and "input high impedance".

[0070] Speed ​​switching:

[0071] When sending data, the TX_h and TX_s pins switch to the "serial output" state.

[0072] After transmission is completed, the TX_h and TX_s pins are immediately switched to the "input high impedance" state to release the TRX line.

[0073] The "input high impedance" state means that the pin has minimal effect on the communication line, allowing other devices to send data.

[0074] 4) Using half-duplex communication mode:

[0075] ·Since single-wire UART communication is used, sending and receiving cannot be performed at the same time, so it is a half-duplex communication method.

[0076] When sending data, the receiver must stop sending and wait until the sending is completed before receiving the data.

[0077] 5) UART data uses a question-and-answer mechanism:

[0078] During the communication process, the party receiving the data must send a response signal to confirm the receipt of the data. The UART data format is as follows: Figure 7 shown.

[0079] · Question-and-answer mechanism helps ensure correct data transmission and synchronization (such as Figure 8 shown).

[0080] In this embodiment, an energy management unit is also included, which is connected to the super capacitor to manage the electrical energy obtained from the UART interface and store it efficiently in the super capacitor.

[0081] This embodiment also provides a passive communication method. The core of the passive operation mechanism is to use the pull-up voltage provided by the RXD and TXD pins of the UART interface when idle to charge the supercapacitor (farad capacitor), and then use the stored electrical energy when the LoRa module needs to perform wireless communication. Specifically, it includes:

[0082] S1. Establish connection: The user device performs handshake protocol with the LoRa transparent transmission module through the UART interface;

[0083] S2, power-on initialization: When the LoRa module is connected to the device, the external device will control the input of the power supply (3.3V) to the TXR line to quickly charge the supercapacitor (when the LoRa module is just powered on, the peripheral MCU Figure 4 Charge_crl's GPIO controls the peripheral main power supply to quickly charge the LoRa module);

[0084] S3, supercapacitor charging: When the LoRa transparent transmission module is in idle state, that is, the UART interface is not working, the RXD and TXD pins of the UART interface of the user equipment are in a high level state, and the voltage on these pins is transferred to the supercapacitor (farad capacitor) through the current limiting resistors R31 and R32 for charging and storing it in the supercapacitor. The function of the current limiting resistor is to prevent the charging current from being too large and protect the supercapacitor. The isolation diodes D1 and D2 prevent the voltage of the supercapacitor from flowing back into the UART interface and affecting the normal operation of the UART interface;

[0085] S4. Energy confirmation: The energy confirmation mechanism is to ensure that the LoRa transparent transmission module has obtained sufficient energy before starting wireless data transmission. Figure 5 , Figure 6As shown, the user equipment initiates an energy confirmation request (sent by the user equipment: 75010400007F 766E), and sends an energy confirmation mechanism data frame through the UART interface. After receiving the energy confirmation request, the LoRa transparent transmission module checks whether the power of the supercapacitor is sufficient to support a complete wireless data transmission. If the power is sufficient, the LoRa transparent transmission module sends an energy confirmation response 5 times through the UART interface (correct response of the passive LoRa transparent transmission module: 7501040000F77608), indicating that it is ready for wireless data transmission; if the power is insufficient, the LoRa transparent transmission module does not respond and continues to charge until the power is sufficient;

[0086] S5. Working of LoRa transparent transmission module: When the energy confirmation response is successfully sent, the LoRa transparent transmission module can use the electric energy stored in the supercapacitor for wireless data transmission when wireless communication is needed, that is, the user device can send data through the UART interface, and the LoRa module converts the data into a wireless signal and sends it out. This mechanism enables the LoRa transparent transmission module to perform wireless data transmission without an external power supply. Due to the high capacity characteristics of the supercapacitor, the electric energy stored in the supercapacitor is sufficient to support the LoRa transparent transmission module to complete one or more wireless data transmissions.

[0087] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A passive communication module, characterized in that: Including LoRa transparent transmission module, super capacitor, and UART interface; The LoRa transparent transmission module is connected to the UART interface, and the LoRa transparent transmission module realizes the conversion of serial port data to LoRa wireless data through the UART interface, and the UART interface is used to exchange data with the user equipment; The LoRa transparent transmission module is equipped with a supercapacitor for storing electric energy obtained from the UART interface. When the LoRa transparent transmission module needs to perform wireless communication, the required electric energy is obtained from the supercapacitor to realize wireless data transmission without an external power supply.

2. A passive communication module according to claim 1, characterized in that: The LoRa transparent transmission module adopts the EasyLink LM401 module, which integrates a single-chip microcomputer, a LoRa communication module, a built-in crystal oscillator and multiple interfaces.

3. A passive communication module according to claim 1, characterized in that: The UART interface is connected to the user device through the RX pin and the TX pin, and obtains electrical energy through the RX and TX pins and stores it in the supercapacitor.

4. A passive communication module according to claim 1, characterized in that: The supercapacitor is a farad capacitor.

5. A passive communication module according to claim 1, characterized in that: An isolation diode and a current limiting resistor are arranged between the super capacitor and the UART interface.

6. A passive communication module according to claim 1, characterized in that: It also includes an energy management unit connected to the supercapacitor to manage the power obtained from the UART interface and store it in the supercapacitor efficiently.

7. A passive communication method, applied to a passive communication module according to any one of claims 1 to 6, characterized in that: include: S1. Establish connection: The user device performs handshake protocol with the LoRa transparent transmission module through the UART interface; S2, power-on initialization: When the LoRa module is connected to the device, the external device will input the power control to the TXR line to quickly charge the supercapacitor; S3, supercapacitor charging: When the LoRa transparent transmission module is in idle state, the RXD and TXD pins of the UART interface of the user equipment are in a high level state, providing a pull-up voltage to charge the supercapacitor and store it in the supercapacitor; S4, Energy confirmation: The user device initiates an energy confirmation request and sends an energy confirmation mechanism data frame through the UART interface. After receiving the energy confirmation request, the LoRa transparent transmission module checks whether the power of the supercapacitor is sufficient to support a complete wireless data transmission. If the power is sufficient, the LoRa transparent transmission module sends an energy confirmation response 5 times through the UART interface, indicating that it is ready for wireless data transmission; if the power is insufficient, the LoRa transparent transmission module does not respond and continues to charge until the power is sufficient; S5. LoRa transparent transmission module works: When the energy confirmation response is successfully sent, the LoRa transparent transmission module can use the electrical energy stored in the supercapacitor for wireless data transmission when wireless communication is needed.

8. A passive communication method according to claim 7, characterized in that: When the supercapacitor is charged, the voltage is transferred to the supercapacitor through the current limiting resistor for charging, which is used to prevent the charging current from being too large and protect the supercapacitor; At the same time, the diode prevents the voltage of the supercapacitor from flowing back into the UART interface, so as to maintain the normal working state of the UART interface.

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