Adafruit INA3221 Triple Channel Power Monitor - STEMMA QT / Qwiic

The Adafruit INA3221 breakout board is a versatile triple-channel power monitor that measures voltage from 0 to 26 VDC and current up to ±3.2 Amps with ±1% precision. Featuring the INA3221 chip, it supports high side voltage and DC current draw measurements of up to three power supplies over I2C.

This sensor solves the multi-rail power-monitoring challenge and is especially valuable as it measures high side current, avoiding issues related to ground reference changes. The built-in 0.05 ohm, 1% sense resistors and a precision amplifier enable high accuracy measurements with 13-bit ADC resolution.

Key features include:

• Measures bus voltages from 0 V to 26 V
• Reports shunt and bus voltage for up to three channels
• High accuracy with ±80 µV offset voltage max and 0.25% max gain error
• Configurable averaging and alert outputs
• Operates from 2.7 V to 5.5 V power supply
• Compatible with STEMMA QT / Qwiic connectors for easy plug-and-play I2C connection
• Includes 3.5mm terminal blocks and a 0.1" pin header for soldering options

The device size is 38.6mm x 22.9mm x 10.5mm, weighing 5.8g. It is ideal for monitoring battery life, solar panels, or multiple power supplies simultaneously in projects.

Use with Arduino, CircuitPython, or Raspberry Pi using provided libraries. No soldering is required for I2C connection thanks to STEMMA QT connectors, though headers are included for breadboard compatibility.