INA219 I²C current and power monitor module — 26V, 3.2A, 12-bit ADC

The INA219 is a high-side DC current and power monitor IC from Texas Instruments, available here as a ready-to-use breakout module. It measures bus voltage, shunt voltage, current, and calculated power over I²C, making it ideal for battery monitoring, solar charge tracking, and any application where precise power consumption measurement is needed. With a 12-bit ADC and programmable gain, it delivers accurate readings across a wide range of currents without interrupting the power path.

Key Specifications:

• Monitor IC: Texas Instruments INA219
• Interface: I²C (addresses 0x40 – 0x4F, configurable via A0/A1 pads)
• Bus voltage range: 0V – 26V
• Max current: ±3.2A (with onboard 0.1Ω shunt resistor)
• ADC resolution: 12-bit
• Shunt resistor: 0.1Ω (onboard)
• Current resolution: ~0.8mA (default), up to 0.1mA with calibration
• Power resolution: ~0.4mW
• Supply voltage (V_S): 3.0V – 5.5V
• Quiescent current: 1mA (max)
• Operating temperature: −40°C to +125°C
• Module dimensions: ~25mm × 10mm

Measured Parameters:

• Shunt voltage: voltage across the shunt resistor (±320mV range)
• Bus voltage: voltage on the load side (0 – 26V)
• Current: calculated from shunt voltage and calibration register
• Power: calculated internally (bus voltage × current)

Pinout:

• VCC: 3.3V – 5V power input
• GND: Ground
• SDA: I²C data
• SCL: I²C clock
• VIN+: High-side power input (connect to power supply positive)
• VIN−: Load output (connect to load positive terminal)
• A0, A1: I²C address configuration pads

I²C Address Configuration:

• A1=GND, A0=GND → 0x40 (default)
• A1=GND, A0=VCC → 0x41
• A1=VCC, A0=GND → 0x44
• A1=VCC, A0=VCC → 0x45

Compatible With:

• Arduino Uno, Nano, Mega (Adafruit INA219 library)
• ESP32 and ESP8266
• Raspberry Pi (Python adafruit-circuitpython-ina219)
• STM32 and other I²C-capable MCUs

Applications:

• Battery charge/discharge monitoring
• Solar panel and MPPT current tracking
• USB power delivery monitoring
• IoT device power profiling
• Motor current sensing
• Smart power distribution boards