/* Pitch follower Plays a pitch that changes based on a changing analog input circuit: - 8 ohm speaker on digital pin 9 - photoresistor on analog 0 to 5V - 4.7 kilohm resistor on analog 0 to ground created 21 Jan 2010 modified 31 May 2012 by Tom Igoe, with suggestion from Michael Flynn This example code is in the public domain. http://www.arduino.cc/en/Tutorial/Tone2 */ void setup() { // initialize serial communications (for debugging only): Serial.begin(9600); } void loop() { // read the sensor: int sensorReading = analogRead(0); // print the sensor reading so you know its range Serial.print("0: "); Serial.print(sensorReading); Serial.print(", 1: "); Serial.print(analogRead(1)); Serial.print(", 2: "); Serial.print(analogRead(2)); Serial.print(", 3: "); Serial.println(analogRead(3)); // map the analog input range (in this case, 400 - 1000 from the photoresistor) // to the output pitch range (120 - 1500Hz) // change the minimum and maximum input numbers below depending on the range // your sensor's giving: int thisPitch = map(sensorReading, 400, 1000, 120, 1500); // play the pitch: // tone(11, thisPitch, 10); delay(250); // delay in between reads for stability }