An Ultra-Low-Power LoRa Mesh for Low-Cost and Real-Time Resort Pool Temperature Monitoring

Real-time temperature monitoring and management of self-sustainable resort hot tubs can be challenging. The absence of electric power cables around the hot tubs limits the types of temperature monitoring techniques that can be used on the property. In this study, a battery-powered, ultra-low-power, and long-range (LoRa) radio transmission mesh for the temperature monitoring of recreational resort mineral pools was developed and tested. The low power consumption was achieved by the software design of the microcontroller and the use of LoRa. Four LoRa followers were tested to receive temperature data from the pools and one LoRa leader was used to receive the data from the followers and pass the data to a PC. The LoRa radio modules used had successful transmissions up to 7.938 km. Acid-resistant and waterproof temperature probes were used for the mineral water environment. The system can operate for up to 99.7 days using 2400 mAh batteries and for years if the battery can be charged by a micro solar cell.