The Elektor LoRa Node Versatile, long-range, 868-MHz remote control with state feedback and STM32 Inside

摘要

The Elektor LoRa Node was born from the idea to have a compact PCB with support for rechargeable as well as non-rechargeable batteries, a common microcontroller like the LQFP48-cased STM32, and a type RFM95 LoRa module, also, the PCB was to fit in an enclosure that's easily sourced from one of the bigger distributors, also, for the STM32 compiler, we... STOP! As the enclosure will co-determine the space available or the energy source, we need to discuss this first. The initial idea was to power the device from non-rechargeable batteries. This was rejected since Elektor wants its contribution to battery waste to be as small as possible. So, a rechargeable battery solution was sought, as well as ease of replacement by the user. This would result in a small, serviceable, water-resistant node capable of operating not only in Elektor Labs' comfy conditions, but also "out there in the wild" and conveying real-life environmental data. Further design aspects heavily debated during the project development period were the battery lifetime and the sensors to accommodate on or off the board. Clearly, we aimed to have a flexible and useful platform to explore LoRa and potentially LoRaWAN, not for 'academic' use in the airco'd and carpeted lab but ready to use in any (rough) place out there for the purpose of remote device on/off switching. From here, the challenge is the 'squaring of the circle' in terms of flexibility, power consumption, and size.