CN211857721U - A wireless centralized meter reading system based on Lora communication - Google Patents

Abstract

A wireless centralized meter reading system based on Lora communication, including terminal equipment for human-computer interaction; a relay processor module, which has a GPRS module for communicating with the terminal equipment; It has a water meter installed with an electric valve to control the on-off of the water circuit. Both the relay processor module and the meter reading module have a LoRa module for long-distance communication transmission between each other, and several communication interfaces for meter reading. The storage module for information storage, the clock module for recording the data sending time during the transmission of meter reading data, and the power supply module for supplying power to the relay processor module and the meter reading module; The LoRa communication technology with long communication distance makes the interference of space and other signals have little impact on the communication of the water meter. Under the same environment, it is easier to meet the needs of users, making the whole meter reading process simpler, thereby improving the reading efficiency. Success rate.

Description

A wireless centralized meter reading system based on Lora communication

technical field

The utility model belongs to the field of wireless centralized meter reading, in particular to a wireless centralized meter reading system based on Lora communication.

Background technique

At present, with the increase of urban residents, the number of water meters is also growing rapidly. Therefore, this paper designs a wireless centralized meter reading system scheme based on Lora communication. The traditional user water meter is improved in the system, a communication network is established between the workstation, the repeater and the water meter, and Lora and GPRS are used for communication to support the water meter sleep. / Wake-up, valve switch, alarm monitoring and other functions, with many advantages such as long transmission distance and low power consumption.

SUMMARY OF THE INVENTION

The technical problem to be solved by the utility model is to provide a wireless centralized meter reading system based on Lora communication, aiming at the deficiencies of the prior art.

The technical problem to be solved by this utility model is realized through the following technical solutions, including:

Terminal equipment for human-computer interaction;

A relay processor module, which has a GPRS module for communicating with the terminal device;

The meter reading module has a water meter installed with an electric valve to control the on-off of the water circuit.

Both the relay processor module and the meter reading module have a LoRa module for long-distance communication transmission between each other, several communication interfaces, a storage module for meter reading information storage, and a period for sending meter reading data. A clock module for recording data transmission time and a power supply module for supplying power to the relay processor module and the meter reading module;

The terminal equipment realizes long-distance data communication through the relay processor module and the meter reading module.

The technical problem to be solved by the present invention can also be achieved by the following technical solutions. In the above-mentioned wireless centralized meter reading system based on Lora communication, the terminal device adopts a microcomputer.

The technical problem to be solved by the present utility model can also be realized by the following technical solutions. In the above-mentioned wireless centralized meter reading system based on Lora communication, the GPRS module adopts SIM800C.

The technical problem to be solved by the present utility model can also be realized by the following technical solutions. In the above-mentioned wireless centralized meter reading system based on LoRa communication, the LoRa module adopts SX1278 communication module.

The technical problem to be solved by the present utility model can also be realized by the following technical solutions. In the above-mentioned wireless centralized meter reading system based on Lora communication, the meter reading module adopts STM8L152M8 microcontroller.

The technical problem to be solved by the present invention can also be achieved by the following technical solutions. In the above-mentioned wireless centralized meter reading system based on Lora communication, the clock module adopts the CMOS real-time clock calendar chip PCF8563.

Compared with the prior art, the beneficial technical effect of the present utility model is: the use of LoRa communication technology with strong anti-interference ability and long communication distance makes the influence of interference such as space and other signals on the communication of the water meter very small, and in the same environment. It is easier to meet the needs of users. Due to the characteristics of Lora technology, the water meter can maintain a stable signal transmission and communication distance in different weather, high/low temperature environments, etc., making the entire meter reading process simpler and improving. The success rate of copying.

Description of drawings

Fig. 1 is the logical block diagram of the data transmission of the present utility model;

FIG. 2 is a schematic diagram of the JTAG interface circuit of the utility model.

Detailed ways

The specific technical solutions of the present invention are further described below with reference to the accompanying drawings, so as to facilitate those skilled in the art to further understand the present invention, but not to limit the rights thereof.

Embodiment 1, referring to Fig. 1-2, a wireless centralized meter reading system based on Lora communication, including,

Terminal equipment 1 for human-computer interaction;

The relay processor module 2 has a GPRS module for communicating with the terminal device 1;

The meter reading module 3 has a water meter installed with an electric valve to control the on-off of the water circuit.

The relay processor module 2 and the meter reading module 3 both have a LoRa module for long-distance communication transmission between each other, several communication interfaces, a storage module for meter reading information storage, and a storage module for sending meter reading. The clock module set for recording the data transmission time during the data period and the power supply module set for giving power to the relay processor module 2 and the meter reading module 3;

The terminal device 1 realizes long-distance data communication through the relay processor module 2 and the meter reading module 3 .

Among them, the external power supply of the relay processor module 2 is a 12V DC power supply, the GPRS module in the relay processor module 2 uses a 4V power supply, and the other modules use a 3.3V power supply, so it is necessary to reduce the voltage to the relay processor module 2. Each module is powered, so this article uses TI's DC-DC power supply voltage stabilizer chip TPS54331 to convert 12V into 3.3V and 4V. The voltage stabilizer circuit formed by the voltage stabilizer chip is very simple and its use methods are also existing methods. Therefore, here The specific connection and wiring diagram of the voltage-stabilizing circuit formed by the voltage-stabilizing chip will not be repeated;

Among them, the meter reading module 3 has a JTAG interface for downloading the program of the single-chip microcomputer, and this setting is used for debugging between the meter reading module 3 and peripheral devices. Figure 2 is a schematic diagram of the JTAG interface circuit, and TRST is an asynchronous reset control line; TDI is the test data input; TMS is the test mode selection, which is used to set which test mode JTAG is in; TCK is the test clock input; TDO is the test data output;

The valve of the water meter realizes the opening and closing of the valve through the electric valve, the meter reading module 3 detects the user's water consumption status, and the relay processor module 2 receives the command and can connect the signal of the meter reading module 3 through the LoRa module at any time to control the electric valve to realize the opening and closing of the water meter valve. The control of the electric valve is in the prior art, so the control method and principle of the electric valve will not be repeated here.

Embodiment 2, a wireless centralized meter reading system based on Lora communication described in Embodiment 1, the terminal device 1 adopts a microcomputer.

Embodiment 3, a wireless centralized meter reading system based on Lora communication described in Embodiment 2, the GPRS module adopts SIM800C.

Among them, GPRS is responsible for the communication between the relay processor module 2 and the microcomputer, and is an important part of the relay processor module 2. Therefore, it is necessary to select a GPRS module with high reliability, easy development and low cost. SIM800C is used as a GPRS module, GPRS module and its peripheral circuits. The power supply voltage of the module is 3.4V~4.4V. The working frequency bands are: GSM850, EGSM900, DCS1800 and PCS1900, of which the transmission power of the GSM850 and EGSM900 frequency bands is 2W, and the transmission power of the DCS1800 and PCS1900 frequency bands is 2W. It is 1W. This module has built-in TCP/IP protocol on the basis of general GPRS module. Users only need MCU to send specific AT commands to SIM800C through the serial port during development and use, and the module can be easily set. After the AT command, the connection between GPRS and the Internet and the data transmission are automatically completed. The development process is very simple, so the development principle of the program in the prior art will not be repeated here. The SIM800C is mainly composed of flash memory, radio frequency module and baseband module. It consists of serial port, LCD interface, voice interface, SIM card interface, keyboard interface, power supply interface and antenna interface. The flash memory is mainly used to store other information such as user address book, device configuration and short message. The radio frequency module mainly modulates and demodulates the signal, and converts the radio frequency signal into information that the baseband module can process. The baseband module mainly processes the voice data signal. Due to the special application of the GPRS module in the relay processor module 2, the LCD in its external interface The interface, sound interface and keyboard interface are not connected to devices. Among the other interfaces, the serial port is connected to the serial port module of STM32, which is mainly used to send and receive AT commands.

Embodiment 4, a wireless centralized meter reading system based on LoRa communication described in Embodiment 3, the LoRa module adopts SX1278 communication module.

This application uses the SX1278 LoRa communication module to transmit the instructions of the relay processor module 2 and the meter reading module 3. SX1278 is a low-power half-duplex long-distance transceiver produced by SEMTECH, which adopts LoRa spread spectrum modulation and demodulation technology. , which makes its transmission distance far beyond the wireless transceiver system using FSK or OOK modulation. When the transmission rate is fast, the sensitivity of using LoRa modulation technology is 8dB higher than that of FSK, and the sensitivity of the transceiver exceeds -148dBm, which is higher than that of FSK modulation. In addition, LoRa has significant advantages in selectivity and blocking performance, which can further improve communication reliability. At the same time, the software configuration of SX1278 has great flexibility, and users can program to determine the spread spectrum modulation bandwidth. (BW), Spreading Factor (SF) and Error Correction Rate (CR). The bandwidth of SX1278 is 7.8~500kHz, the spreading factor is 6~12, and the frequency range is 137~525MHz. The antenna frequency here is 433MHz. Since each spreading factor of spread spectrum modulation is orthogonally distributed, multiple transmission signals occupy The same channel will not interfere with each other and can coexist with systems based on FSK modulation technology. In addition, SX1278 also supports standard GFSK, FSK, OOK and GMSK modulation modes, so it can be compatible with existing M-BUS and IEEE 802.15.4g It is compatible with other systems or standards, and is mainly used in wireless meter reading, home and building automation, wireless alarm and security systems, industrial monitoring, and remote irrigation systems. principles and methods.

Embodiment 5, a wireless centralized meter reading system based on Lora communication described in Embodiment 4, the meter reading module 3 adopts the STM8L152M8 microcontroller.

Among them, the hardware part of the meter reading module 3 uses the microcontroller STM8L152M8 produced by low-power STMicroelectronics as the control core. The STM8L152M8 is based on the 8-bit STM8 core and adopts a proprietary ultra-low leakage current process. In the lowest power consumption mode A current of 0.3μA is achieved, and its main features are: (1) Ultra-low power consumption: This design uses STM8L series MCU, the main advantage lies in its ultra-low power consumption, which is embodied in the following aspects: 1. The use of wait mode, There are five low-power modes: low-power running mode, low-power standby mode, active stop mode, and stop mode. Different modes can be selected in different occasions to achieve a balance between performance and power consumption. When using an internal low-speed clock, In low power mode, the maximum current consumption is 350μA, the minimum current consumption is 0.35μA, 50nA ultra-low I/O port leakage current, dynamic power consumption is 192μA/MHz, 2. There are four different clock sources: 1-16MHz to tell the external crystal oscillator (HSE ), 16MHz high-speed internal oscillator (HSI), 32.768 low-speed external crystal oscillator (LSE), 38kHz low-speed internal oscillator (LSI), in digital circuits, the faster the clock speed, the higher the power consumption of the system. The speed requirements of tasks will not be the same. Urgent tasks require high-speed clocks, while waiting for external events, the lower the clock, the better. In STM8L microcontrollers, high-speed and low-speed clocks can be switched even when the MCU is running, and the clock is divided. The MCU can divide the clock frequency through an instruction to further coordinate the system power consumption and performance. 3. Generally, it is impossible for all the peripherals inside the MCU to be applied to a design without using or temporarily not using them. Peripherals will consume current as long as they have clocks. In STM8L, all peripheral clocks can be turned off or turned on individually, and peripherals can be selectively turned on or off according to the needs of use, which can reduce unnecessary power consumption, 4 , In order to further reduce power consumption, STM8L can stop the clock of the core, memory and peripherals, and recover only by external interrupts. The interrupt wake-up time is 5μs, which not only reduces system power consumption, but also responds quickly to external events, (2 ) has a wealth of on-chip peripherals: low-power RTC clock, DMA, ADC analog-to-digital conversion, comparator, timer counter, IC, SPI, UART, in which the RTC clock can save the monthly and daily data, and the ADC can Detect battery power, timer counter can wake up the device regularly to detect sensor status, SPI can complete the initial configuration of SX1278, UART communication can modify the internal parameters of the water meter and read related data, the on-chip peripheral of STM8L provides great convenience for design , reducing the circuit volume and reducing the cost; (3) Embedded memory: STM8L integrates 256 bytes of data storage space, which has the advantages of no loss of data when power off, fast data storage speed, electrical erasability, and high reliability. , for the power failure protection of important data such as water meter address, flow data and equipment status It is possible to save the water meter, so that the water meter can be restored to the state before the power failure immediately after the power is turned on again;

Embodiment 6, a wireless centralized meter reading system based on Lora communication described in Embodiment 5, the clock module adopts CMOS real-time clock and calendar chip PCF8563.

That is, the relay processor module 2 is connected to the client, namely the microcomputer, through the GPRS network, forming a bridge between the water meter and the remote workstation. The workstation and the microcomputer issue meter reading instructions through the GPRS network, and the relay processor module 2 sends the data to the water after receiving it. The meter terminal is the meter reading module 3, and the repeater is the relay processor module 2 for signal forwarding. After the meter reading module 3 receives the meter reading instruction, it sends the data to the relay processor module 2 through the Lora module, and the relay The processor module 2 uploads the data to the workstation, that is, the terminal device 1, that is, the microcomputer through the GPRS network, thereby completing the wireless meter reading process. During the period, the clock module will provide a time stamp, and the data will leave a time node when reading the meter. The utility model The use of Lora module has the advantages of long communication distance, low power consumption, sleep wake-up, etc. Its structure design is reasonable, the whole meter reading process is simpler, and the success rate of reading is improved.

Claims (6)

1. The utility model provides a wireless centralized meter reading system based on Lora communication which characterized in that: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

the terminal equipment is used for man-machine interaction;

the relay processor module is provided with a GPRS module which is used for being in communication connection with the terminal equipment;

the meter reading module is provided with a water meter which is provided with an electric valve for controlling the on-off of the water path;

the relay processor module and the meter reading module are respectively provided with a LoRa module, a plurality of communication interfaces, a storage module, a clock module and a power supply module, wherein the LoRa module is used for carrying out long-distance communication transmission between the LoRa module and the meter reading module, the storage module is used for storing meter reading information, the clock module is used for recording data sending time during sending meter reading data, and the power supply module is used for supplying power to the relay processor module and the meter reading module;

the terminal equipment realizes remote data communication with the meter reading module through the relay processor module.

2. The wireless centralized meter reading system based on Lora communication according to claim 1, wherein: the terminal equipment adopts a microcomputer.

3. The wireless centralized meter reading system based on Lora communication according to claim 1, wherein: the GPRS module employs SIM 800C.

4. The wireless centralized meter reading system based on Lora communication according to claim 1, wherein: the LoRa module adopts an SX1278 communication module.

5. The wireless centralized meter reading system based on Lora communication according to claim 1, wherein: the meter reading module adopts an STM8L152M8 microcontroller.

6. The wireless centralized meter reading system based on Lora communication according to claim 1, wherein: the clock module adopts a CMOS real-time clock calendar chip PCF 8563.

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