Teensy 4.1 INA226 Current Sensor Tutorial

Tutorial Aim:

The goal of this tutorial is to read and display the INA226 sensor output using a Teensy 4.1

The INA226 is a precision dual-function voltage and current sensor that is designed to accurately measure both the voltage and the current flowing through a shunt resistor. The device is commonly used in a variety of power management and monitoring applications.

Requirements:

This tutorial makes use of the Arduino IDE & the Arduino Starter Pack

Arduino IDE v.2.21 or later
Teensy 4.0/4.1 microcontroller
INA226 Current Sensor
6 Male to Female Jumper Wires
3 Male to Male Jumper Wires
Breakout Board
1 LED
80Ohm Resistor

Pin Layout:

The pin layout is shown below.

Sensor Pins:	Teensy Pins:
GND	GND
VCC	5V
SDA	18
SCL	19

Setup:

Refer to the image below for wiring.

Connect the current sensor’s SDA pin to pin 18 & SCL pin to pin 19 on the Teensy 4.1 using the FM jumper wires.
Open Arduino IDE
Plug in the Teensy 4.1 to the computer

Code Walk Through:

Libraries:

To access & use the current sensor we include the INA226.h library by Rob Tillaart. As the current sensor uses I2C protocol to communicate with microcontrollers the Wire.h library is also needed.

For information about the INA226.h library by Rob Tillaart please visit his Github.

#include <Wire.h>
#include "INA226.h"
 
INA226 INA(0x40);

Initiating the sensor:

Using the INA226 library we can initialize the sensor with our I2C address (0x40), test if the sensor begins & set the max current shunt.

To avoid sensor connection issues, please ensure that you have the correct I2C address. This can be checked using i2c_scanner example found in the Wire library.

// Initialising the INA226 sensor
void setup() {
  Serial.begin(9600);

  Wire.begin();
  if (!INA.begin()) { Serial.println("could not connect. Fix and Reboot"); }
  INA.setMaxCurrentShunt(1, 0.002);
}

Gathering the sensor data:

We can gather and display the sensor’s bus voltage, shunt voltage, current, & power readings every 2 seconds.

// Polling & displaying the sensor readings every 2 seconds
void loop() {
  Serial.print("\nBus Voltage:");
  Serial.print(INA.getBusVoltage(), 3);

  Serial.print("\tShunt Voltage(mV): ");
  Serial.print(INA.getShuntVoltage_mV(), 3);

  Serial.print("\tCurrent(mA): ");
  Serial.print(INA.getCurrent_mA() / 10, 3);

  Serial.print("\tPower(mW): ");
  Serial.print(INA.getPower_mW(), 3);
  delay(2000);
}

Current Sensor Code:

Entire tutorial code for your reference:

#include <Wire.h>
#include "INA226.h"

INA226 INA(0x40);

// Initialising the INA226 sensor
void setup() {
  Serial.begin(9600);

  Wire.begin();
  if (!INA.begin()) { Serial.println("could not connect. Fix and Reboot"); }
  INA.setMaxCurrentShunt(1, 0.002);
}

// Polling & displaying the sensor readings every 2 seconds
void loop() {
  Serial.print("\nBus Voltage:");
  Serial.print(INA.getBusVoltage(), 3);

  Serial.print("\tShunt Voltage(mV): ");
  Serial.print(INA.getShuntVoltage_mV(), 3);

  Serial.print("\tCurrent(mA): ");
  Serial.print(INA.getCurrent_mA() / 10, 3);

  Serial.print("\tPower(mW): ");
  Serial.print(INA.getPower_mW(), 3);
  delay(2000);
}

Serial Output:

The sensor readings are displayed on the serial monitor.

Downloadable Content:

Please find this tutorial's code on our Github page.

Credits:

Arduino
The Arduino Community
The STEM Community

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