Rudolph

rudolph.ino

/* Play Melody
* -----------
*
* Program to play a simple melody
*
* Tones are created by quickly pulsing a speaker on and off
*   using PWM, to create signature frequencies.
*
* Each note has a frequency, created by varying the period of
*  vibration, measured in microseconds. We'll use pulse-width
*  modulation (PWM) to create that vibration.

* We calculate the pulse-width to be half the period; we pulse
*  the speaker HIGH for 'pulse-width' microseconds, then LOW
*  for 'pulse-width' microseconds.
*  This pulsing creates a vibration of the desired frequency.
*
* (cleft) 2005 D. Cuartielles for K3
* Refactoring and comments 2006 [email protected]
* See NOTES in comments at end for possible improvements
*/

// TONES  ==========================================
// Start by defining the relationship between
// note, period & frequency.
const int c4 = 261; // Hz
const int d4 = 294; // Hz
const int e4 = 329; // Hz
const int f4 = 349; // Hz
const int g4 = 392; // Hz
const int a4 = 440; // Hz
const int b4 = 493; // Hz
const int c5 = 523; // Hz
// Define a special note, 'R', to represent a rest
const int R = 0;

// MELODY and TIMING  =======================================
// melody[] is an array of notes
const int melody[] = {
    g4, a4, g4, e4, c5, a4, g4,
    g4, a4, g4, a4, g4, c5, b4,
    f4, g4, f4, d4, b4, a4, g4,
    g4, a4, g4, a4, g4, a4, e4,
    R
};
// beats[] is and array which sets each note's relative
// length (higher #, longer note)
const int beats[] = {
    16, 16, 32, 32, 32, 32, 96,
    16, 16, 16, 16, 32, 32, 128,
    16, 16, 32, 32, 32, 32, 96,
    16, 16, 16, 16, 32, 32, 128,
    128
};
// pin numbers of corresponding lights, or "0" if no light
const int lights[] = {
    9, 2, 3, 2, 3, 9, 3,
    9, 2, 3, 9, 2, 3, 2,
    9, 3, 9, 2, 3, 9, 2,
    9, 3, 2, 9, 3, 2, 3,
    0
};
// Melody length, for looping
const int melody_length = 29;
// Set overall tempo
const int tempo = 15;

// SETUP ============================================
// Set up speaker on pin A5
const int speakerPin = A5;

void setup() {
    pinMode(2, OUTPUT);
    pinMode(3, OUTPUT);
    pinMode(9, OUTPUT);
}

// LET THE WILD RUMPUS BEGIN =============================
void loop() {
    // Set up a counter to pull from melody[] and beats[]
    for (int i = 0; i < melody_length; i++) {
        // Tone duration
        long duration = beats[i] * tempo;
        digitalWrite(lights[i], HIGH);
        // Play the note
        tone(speakerPin, melody[i], duration);
        digitalWrite(lights[i], LOW);
        // Wait the note to finish
        delay(duration);
    }
}