Lesson 3 – Analog Input and Sound

Alt Title: Battle of the bands

Introduction

ask for two students that will volunteer to sing in front of the class.  One will sing as if they are a digital signal (on or off, nothing in between) and the other will since as if they are a digital signal (can use any note and volume).

Lesson

1. Read through and complete the tutorial about using an analog input to control a piezo buzzer – http://arduino.cc/en/Tutorial/Tone2
2. Make the most face melting musical device you can in the remaining class time.
   • Remember that you have 2 photoresistors, a temperature sensor, and 2 potentiometers
3. Battle of the bands in the last 5 minutes of class.
4. All bands recital during closing circle.

/*
  Pitch follower

 Plays a pitch that changes based on a changing analog input

 circuit:
 * 8-ohm speaker on digital pin 8
 * photoresistor on analog 0 to 5V
 * 4.7K resistor on analog 0 to ground

 created 21 Jan 2010
 by Tom Igoe

http://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.println(sensorReading);
  // map the pitch to the range of the analog input.
  // change the minimum and maximum input numbers below
  // depending on the range your sensor's giving:
  int thisPitch = map(sensorReading, 400, 1000, 100, 1000);

  // play the pitch:
  tone(8, thisPitch, 10);

}

Additional Resources:

• http://arduino.cc/en/Reference/Tone
• http://arduino.cc/en/Tutorial/Tone