High Side DC Current Sensor – INA219

INA219 High Side DC Current Sensor Breakout

If you want to sort out all your power monitoring issues, consider this breakout board sensor – it will sort them all out.

Thanks to the INA219 chip on this breakout board, you’ll no longer have to struggle with two multimeters to measure both the high-side voltage and the DC current draw, as the INA219B chip will measure both with 1% accuracy via I2C.

Furthermore, the INA219 chip can handle high-side current measurements up to +26 VDC, even when powered at 3 or 5 V. What’s more, it will report the optimal high-side voltage for tracking battery life or solar panel performance, for example.

A precision amplifier measures the voltage across the 0.1 ohm, 1% sense resistor. As the amplifier’s maximum input differential is ±320 mV, it follows that this can measure up to ±3.2 A. With the internal 12-bit ADC, the resolution within the ±3.2 A range is 0.8 mA. With the internal gain set to the minimum of div8, the maximum current is ±400 mA and the resolution is 0.1 mA. More experienced users will be able to remove the 0.1 ohm current sensing resistor and replace it with their own to adjust the range (for example, 0.01 ohm to measure up to 32 A with a resolution of 8 mA).

This product includes, in addition to the breakout board, a 6-pin header (so you can easily connect this sensor to a breadboard) and a 3.5 mm terminal block (so you can easily connect and disconnect the load).

Using this current sensor is very straightforward. Power the sensor with 3 to 5 VDC and connect the two I2C pins to your microcontroller. Then, connect your target power supply to VIN+ and the load to ground via VIN-. Check out Adafruit’s detailed tutorial (for the INA219 sensor, link in the technical details) which will calculate all the gain, range and maths for you; all you need to do is connect it and get started with Arduino or CircuitPython.

Another feature of this Adafruit product is the inclusion of STEMMA QT connectors, compatible with SparkFun Qwiic,for the I2C bus. So you don’t even need to solder either the I2C lines or the power lines. Simply connect to your microcontroller using a STEMMA QT adapter cable. Using the STEMMA QT connectors also allows you to use the INA219 with various associated accessories.

Note: The QT cable is not included, but you can purchase various types from us.

Technical Details of the High-Side DC Current Sensor Breakout – INA219

Revision history:

• As of 29 January 2021, Adafruit has updated the design of this sensor. There are now four mounting holes and two STEMMA QT connectors for plug-and-play connectivity. The schematic remains the same; only the mechanical form has changed.
• The datasheet, Fritzing and EagleCAD PCB files are available in the product tutorial.
• 0.1 ohm 1% 2W current sensing resistor
• Target voltage up to +26V.
• Current measurement up to ±3.2 A, with a resolution of ±0.8 mA.
• This board/chip uses the 7-bit I2C addresses 0x40, 0x41, 0x44 and 0x45, which can be selected via jumpers.
• Note: the terminal block included with the product may be blue or black.
• Dimensions: 2.56×2.04×0.47 cm / 1.0″x0.8″x0.2″.

Adafruit name: INA219 High Side DC Current Sensor Breakout – 26V ±3.2A Max – STEMMA QT [ADA904]