INA219 I2C Bi-Directional Current and Power Monitor Sensor Module

The INA219 module is a high-side current, voltage and power monitor with an I2C interface, built around the Texas Instruments INA219 zero-drift power monitor IC. It measures the voltage drop across an onboard shunt resistor along with the bus voltage, then reports current in amps and power in watts directly. Current sensing is bi-directional, so it can track both charging and discharging in battery and power supply projects. It works with Arduino, ESP32, Raspberry Pi and any other 3.3V or 5V I2C microcontroller.

Key Features

• Measures bus voltage, shunt voltage, current and power
• Bi-directional current sensing (charging and discharging)
• High-side measurement, so the load keeps its ground reference
• 12-bit ADC with programmable averaging of up to 128 samples to reduce noise
• I2C interface with 16 selectable addresses (0x40 to 0x4F), so multiple modules can share one bus
• Powered from 3.0V to 5.5V, drawing 1mA maximum
• Operating temperature range of -40°C to 125°C

Specifications

• Sensor IC: Texas Instruments INA219
• Bus voltage range: 0 to 26V DC (never exceed 26V on the input terminals)
• Current range: up to ±3.2A with the onboard 0.1 ohm shunt (±320mV full scale)
• Current resolution: 0.8mA at full range
• Supply voltage: 3.0V to 5.5V
• Interface: I2C / SMBus compatible, up to 400kHz fast mode and 2.56MHz high-speed mode
• Default I2C address: 0x40

Pinout

• VCC: 3.0V to 5.5V supply
• GND: Ground
• SCL: I2C clock
• SDA: I2C data
• VIN+: Connect to the positive supply side of the circuit being measured
• VIN-: Connect to the load side. Current flows from VIN+ through the shunt to VIN-

Changing the I2C Address

The A0 and A1 address pads on the module let you select up to 16 addresses from 0x40 to 0x4F. Bridging the pads to GND, VS, SDA or SCL sets the address, which allows several INA219 modules to monitor separate circuits on a single I2C bus.

Wiring to Arduino

• VCC to 5V (or 3.3V on 3.3V boards)
• GND to GND
• SDA to A4 and SCL to A5 (Arduino Uno and Nano)
• VIN+ to the positive power source and VIN- to the positive side of the load

The module ground must be shared with the ground of the circuit being measured.

Applications

• Battery charge and discharge monitoring
• Solar and power supply monitoring
• Energy usage logging and data loggers
• Over-current detection in robotics and power distribution
• Bench power profiling for IoT and embedded projects

Documentation

INA219 datasheet (PDF)

This product can be found here:

• Components & Parts
• Development Boards
• Sensors