Pololu ACHS-7121

/*
The Pololu ACHS-7121 Current Sensor Carrier is a carrier board for the Allegro ACS712 Hall effect-based linear current sensor. Here's an example code in Arduino that reads the current from the sensor:

Note: This code assumes that the Pololu ACHS-7121 Current Sensor Carrier is connected to pin A0 of the Arduino board. If you're using a different pin, you'll need to modify the SENSOR_PIN definition accordingly. Also, the sensitivity of the sensor is assumed to be 185 mV/A, which corresponds to the ACS712ELC-10A version of the sensor. If you're using a different version of the sensor, you'll need to adjust the sensitivity accordingly.
*/

const int SENSOR_PIN = A0;  // the pin connected to the sensor
float voltage;  // the voltage reading from the sensor
float current;  // the current calculated from the voltage

void setup() {
  Serial.begin(9600);

  pinMode(SENSOR_PIN, INPUT);
}

void loop() {
  // read the voltage from the sensor
  voltage = analogRead(SENSOR_PIN) * (5.0 / 1023.0);

  // calculate the current flowing through the sensor in amps
  current = ((voltage - 2.5) / 0.185);

  // print the current flowing through the sensor
  Serial.print("Current: ");
  Serial.print(current);
  Serial.println(" A");

  // delay before reading from the sensor again
  delay(1000);
}