Current and voltage measurement with INA226 and ESP8266 by MQTT
Not maintained anymore. Now integrated into OpenMQTTGateway, please see below: https://github.com/1technophile/OpenMQTTGateway
More info below:
http://shelvin.de/ein-batteriemonitor-fuer-strom-und-spannung-mit-dem-ina226-und-dem-arduino-uno/ (german)
https://1technophile.blogspot.fr/2017/03/ina226-voltage-and-current-sensor-mqtt.html (english)