Read the ADC pin on an Arduino

adc.ino

/*
* Read analog voltage on pin 0 send to serial port every 3 seconds
*/

const int analogInPin0 = A0; // Analog input pin
int sensorValue0 = 0;

void setup() {
  // initialize serial communications at 9600 bps:
  Serial.begin(9600);
}

void loop() {
  // read the analog pin
  sensorValue0 = analogRead(analogInPin0);
  delay(4);

  // print the results to the serial monitor:
  Serial.print("sensorValue0 = " );
  Serial.println(sensorValue0);

  // wait 3 seconds before the next readings
  delay(3000-4);
}