Flash Sonoff S20 WiFi outlet with custom MQTT firmware

Sonoff S20 (specs) is a smart power outlet that is controllable with a WiFi connection. The device comes with a built-in firmware and an accompanied mobile app, but it is also possible to flash it with custom firmware. This allows to control the device with standard MQTT protocol making integration to DIY home automation or IoT cloud systems easier. This post provides a step-by-step guide how to flash the device and also examples how to interface with it using MQTT. Continue reading “Flash Sonoff S20 WiFi outlet with custom MQTT firmware”