Abstract:With the rapid development of the prepared dish industry,the problem of remote monitoring and management of its refrigerated environment has become increasingly serious.In view of the problems that real-time data cannot be uploaded and the cost of manning the refrigerated equipment is high,this study designed a set of Internet of Things monitoring terminal based on LoRa technology.The core controller of the system adopts STM32F429 chip,the node and gateway data transmission equipment adopts LoRa transmision module,and the sensor is combined to collect the working parameters of the refrigerated equipment.Using LoRa module to build a star ADhoc network,the data of the terminal node is transmitted to the gateway in the mode of host polling,uploaded to the cloud platform through 4G and displayed visually.The temperature and humidity of the refrigerated equipment,the ambient temperature and the working current of the compressor were tested.The effective communication distance of LoRa in complex and open environment is tested.The results show that the communication distance of LoRa in complex environment is 300 m,in open environment can reach 500 m,the system performance is stable and reliable,and can meet the needs of data monitoring of prefabricated vegetable refrigeration equipment.