INA219 Bidirectional Current and Power Monitor Module

Reading current with a plain shunt resistor and an analog pin means calculating power draw by hand from a raw voltage difference; the INA219 does that math onboard and hands a microcontroller current, voltage and power readings directly over I2C. It measures bus voltage up to 26V and current up to plus or minus 3.2A at 0.8mA resolution, or a finer plus or minus 400mA range when higher precision on smaller currents matters more than headroom.

Being bidirectional means it reads current flowing either direction through the shunt, which matters for anything involving a battery that both charges and discharges - a solar setup, a battery management project - not just one-way current draw. Up to 128 samples can be averaged in hardware for a cleaner reading in an electrically noisy environment, without extra filtering code on the microcontroller side.

Common uses are battery power monitoring, solar charge controller current sensing, and any project needing to log actual power consumption rather than assuming it from a nameplate rating.