SwitchDoc Labs SDL_Arduino_INA3221 Library
SwitchDoc Labs - www.switchdoc.com
Version 1.1 January 31, 2015
The INA3221 is Triple-Channel, High-SideMeasurement, Shunt and Bus Voltage Monitor with I2C Interface
It is used in the SwitchDoc Labs Solar Controller Product, SunAirPlus and in a standalone SwitchDoc Labs INA3221 Breakout Board
http://www.switchdoc.com/sunairplus-solar-power-controllerdata-collector/
Thanks to the original Adafruit INA219 library, although very little of it ended up being used The INA3221 is a much different beast than the INA219.