Erriez INA219 I2C/SMB Voltage/Current/Power Monitor library for Arduino

This is an INA219 I2C/SMB DC Voltage/Current/Power sensor library for Arduino.

Library features

• High Accuracy: max 0.5%
• Measure Voltage 0..26V DC
• Measure Current 0..2000mA DC (with default 0.1 Ohm shunt)
• Measure Power in Watt (Software Voltage * Current calculation)
• Configurable shunt resistor value
• Configurable I2C address for multiple sensors
• Power-down / power-up control
• Low-level register access

Hardware

Any Arduino hardware with a TWI interface and Wire.h support.

Pins board - INA219	VCC	GND	SDA	SCL
Arduino UNO (ATMega328 boards)	5V	GND	A4	A5
Arduino Mega2560	5V	GND	D20	D21
Arduino Leonardo	5V	GND	D2	D3
Arduino DUE (ATSAM3X8E)	3V3	GND	20	21
ESP8266	3V3	GND	GPIO4 (D2)	GPIO5 (D1)
ESP32	3V3	GND	GPIO21	GPIO22

Examples

• ErriezINA219AutoRange Auto range example.
• ErriezINA219GettingStarted Getting started example.
• ErriezINA219SerialPlotter Serial Plotter example.

Documentation

• Doxygen online HTML
• Doxygen PDF
• INA219 datasheet

Library dependencies

• Wire.h

Getting started

{c++}
#include <Arduino.h>
#include <Wire.h>

#include <ErriezINA219.h>

// Default I2C Address 0x40
#define INA219_I2C_ADDRESS      0x40

// 0.1 Ohm shunt resistor
#define INA219_SHUNT_RESISTOR   0.1

// Create INA219 sensor object
INA219 ina219 = INA219(INA219_I2C_ADDRESS, INA219_SHUNT_RESISTOR);


void setup()
{
    // Initialize serial port
    Serial.begin(115200);
    while (!Serial) {
        ;
    }
    Serial.println(F("\nErriez INA219 voltage, current and power sensor example\n"));

    // Initialize I2C
    Wire.begin();
    Wire.setClock(400000);

    // Initialize INA219
    while (!ina219.begin()) {
        Serial.println(F("Error: INA219 not detected"));
        delay(3000);
    }
}

void loop()
{
    // Read from sensor
    if (!ina219.read()) {
        Serial.println(F("Error: INA219 read failed"));
        return;
    }

    // Check valid conversion
    if (!ina219.available) {
        Serial.println(F("Error: INA219 not available"));
        return;
    }

    // Print result
    Serial.println(F("INA219:"));

    Serial.print(F("  Bus voltage:   "));
    Serial.print(ina219.busVoltage, 2);
    Serial.println(F(" V"));

    Serial.print(F("  Shunt voltage: "));
    Serial.print(ina219.shuntVoltage / 1000, 1);
    Serial.println(F(" V"));

    Serial.print(F("  Current:       "));
    Serial.print(ina219.current / 1000, 1);
    Serial.println(F(" A"));

    Serial.print(F("  Power:         "));
    Serial.print(ina219.power / 1000, 1);
    Serial.println(F(" W"));

    // Wait some time
    delay(1000);
}

Library installation

Please refer to the Wiki page.

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