Abstract:A remote monitoring system of pig shed environment based on LoRa is proposed in view of the shortcomings of the short distance, the complex network and the weak anti-interference ability of the wireless monitoring network in piggery environment. According to the requirements of data transmission distance and low power consumption, a wireless network based on LoRa technology is proposed.
The hardware structure of LoRa terminal node shown in Fig.1.STM32F103 chip through the SPI port (MISO: main device input, output from the device, MOSI: main device output, input from the device, SCK: clock signal line, NSS: from device enable signal) to achieve data transmission with the SX1278, and its register configuration, DIO0-DIO5 is responsible for implementing the interrupt request and capture between the two. SX1278 is a half-duplex transceiver chip, designed to switch, receive and send by radio frequency switching two modes, if the MCU control radio frequency switch through the transmission circuit, SX1278 initialization for emission mode; if the control switch is connected to the receive circuit, the SX1278 is initialized to receive mode, and the system is in a sleep wait state.
Software programming were implemented in Keil µVision5 ID software development system with language C, and the protocol stack based on LoRaWAN.The concentrator software flowchart is shown . When the concentrator is powered on, it sends the device identification message to the host computer and gets the response and then enters the timer interrupt .Through the AT command, it inquires whether the GPRS receives the server data, and then enters the message processing loop after receiving the instruction.
After the system is simulated in the laboratory, on-site installation of pig farms in Yixing City, Jiangsu Province. According to the individual characteristics of pig, it is divided into farrowing house, fattening house and other single pig house, each system is equipped with a concentrator and six acquisition points to test the system. The results show that the LoRa wireless module runs stably, in the high temperature / low temperature, clear / cloudy weather to wake up the transmission of data, the success rate of more than 99%; The terminal device is tested in different sleep periods, and the operating current is too small to realize the low power consumption performance index; The concentrator is stable with the server and receives instructions in time.
In this paper, the remote environment monitoring system of pig farms designed by LoRa technology is used to realize multi-point meas urement, which can solve the problems of remote and low power consumption. Through the system test, LoRa wireless network communication has the advantages of distance, low power consumption, convenient networking, stable server operation and so on. According to the actual needs of the corresponding implementation of equipment for real-time control, for the pig to create a comfortable growth environment.
