Sonoff Firmware with MQTT and Multiple incoming topics and support for DHT22 sensor.
Topic is the main MQTT topic that turns the relay on and off Topic2 is a second incoming MQTT topic that allows you to turn the led on and off. When button is pressed it publishes a to MQTT topic this allows you to handle the press in OpenHAB or Node-Red
This firmware also allows you to hook a DHT22 sensor up to the extra GPIO pin (14) on the Sonoff and get temperature and humidity readings via a MQTT topic.
This is a simple sketch for sonoff devices that allows MQTT. This is based off of https://github.com/SuperHouse/BasicOTARelay but I customized for my needs
Please see the Wiki for more information and how to install