INA219 Current Sensor

Wiring

INA219 Pin	Arduino Pin
VCC	3.3V or 5V
GND	GND
SDA	A4 (SDA)
SCL	A5 (SCL)
Vin+	Power supply +
Vin-	Load +

Code

Install Adafruit INA219 library first.

#include <Wire.h>
#include <Adafruit_INA219.h>
Adafruit_INA219 ina219;
void setup() {
  Serial.begin(115200);
  ina219.begin();
}
void loop() {
  Serial.print("Bus V: "); Serial.print(ina219.getBusVoltage_V());
  Serial.print(" V, Current: "); Serial.print(ina219.getCurrent_mA());
  Serial.print(" mA, Power: "); Serial.print(ina219.getPower_mW());
  Serial.println(" mW");
  delay(1000);
}

Specifications

• Voltage: 0–26V
• Current: up to ±3.2A (with 0.1Ω shunt)
• I2C address: 0x40 (default)

Troubleshooting

• Shows 0V — Vin+/Vin- not connected in series with load
• Wrong current — INA219 must be IN SERIES, not in parallel