Buzzer example function for the CEM-1203 buzzer (Sparkfun's part #COM-07950).

buzzer.pde

// Buzzer example function for the CEM-1203 buzzer (Sparkfun's part #COM-07950).
// by Rob Faludi
// http://www.faludi.com

// Additions by Christopher Stevens
// http://www.christopherstevens.cc

//referenced from http://www.phy.mtu.edu/~suits/notefreqs.html
//starting with F noteFreqArr[1]
int noteFreqArr[] = {
49.4, 52.3, 55.4, 58.7, 62.2, 65.9, 69.9, 74, 78.4, 83.1, 88, 93.2,
98.8, 105, 111, 117, 124, 132, 140, 148, 157, 166, 176, 186,
198, 209, 222, 235, 249, 264, 279, 296, 314, 332, 352, 373,
395, 419, 444, 470, 498, 527, 559, 592, 627, 665, 704, 746,
790, 837, 887, 940, 996, 1050, 1110, 1180, 1250, 1320, 1400, 1490,
1580, 1670, 1770, 1870, 1990, 2100};

long mode = 0;

void setup() {
  pinMode(4, OUTPUT); // set a pin for buzzer output
}

void playNote(long noteInt, long length, long mode, long breath = 25) {
  length = length - breath;
 
  long noteInt2 = noteInt + 12; //1 octave up
  long noteInt3 = noteInt + 24; //2 octaves up
  long noteInt4 = noteInt + 36; //3 octaves up
 
  long playLoop = length / 100; //divide length by 4, for use in play sequence
 
  if(mode == 0) { //mode 0 sequence
    for (long i=0; i < playLoop; i++){
      buzz(4, noteFreqArr[noteInt], 20);
      delay(5);
      buzz(4, noteFreqArr[noteInt2], 20);
      delay(5);
      buzz(4, noteFreqArr[noteInt3], 20);
      delay(5);
      buzz(4, noteFreqArr[noteInt4], 20);
      delay(5);
    }
  } else if(mode == 1) { //mode 1 sequence
    for (long i=0; i < playLoop; i++){
      buzz(4, noteFreqArr[noteInt3], 20);
      delay(5);
      buzz(4, noteFreqArr[noteInt4], 20);
      delay(5);
      buzz(4, noteFreqArr[noteInt3], 20);
      delay(5);
      buzz(4, noteFreqArr[noteInt4], 20);
      delay(5);
    }
  } else if(mode == 2) { //mode 2 sequence
    for (long i=0; i < playLoop; i++){
      buzz(4, noteFreqArr[noteInt3], 20);
      delay(5);
      buzz(4, noteFreqArr[noteInt3], 20);
      delay(5);
      buzz(4, noteFreqArr[noteInt3], 20);
      delay(5);
      buzz(4, noteFreqArr[noteInt2], 20);
      delay(5);
    }
  } else if(mode == 3) { //mode 3 sequence
    for (long i=0; i < playLoop; i++){
      buzz(4, noteFreqArr[noteInt4], 40);
      delay(5);
      buzz(4, noteFreqArr[noteInt2], 40);
      delay(5);
    }
  }
  if(breath > 0) { //take a short pause or 'breath' if specified
    delay(breath);
  }
}

void loop() {
  //main course
  playNote(12, 500, mode);
 
  playNote(5, 1000, mode);
  playNote(7, 250, mode);
  playNote(10, 250, mode);
  playNote(9, 250, mode);
  playNote(7, 250, mode);
  playNote(12, 500, mode);
  playNote(12, 500, mode);
  playNote(12, 250, mode);
  playNote(14, 250, mode);
  playNote(9, 250, mode);
  playNote(10, 250, mode);
  playNote(7, 500, mode);
  playNote(7, 500, mode);
  playNote(7, 250, mode);
  playNote(10, 250, mode);
  playNote(9, 250, mode);
  playNote(7, 250, mode);
  playNote(5, 250, mode);
  playNote(17, 250, mode);
  playNote(16, 250, mode);
  playNote(14, 250, mode);
  playNote(12, 250, mode);
  playNote(10, 250, mode);
  playNote(9, 250, mode);
  playNote(7, 250, mode);
 
  playNote(5, 1000, mode);
  playNote(7, 250, mode);
  playNote(10, 250, mode);
  playNote(9, 250, mode);
  playNote(7, 250, mode);
  playNote(12, 500, mode);
  playNote(12, 500, mode);
  playNote(12, 250, mode);
  playNote(14, 250, mode);
  playNote(9, 250, mode);
  playNote(10, 250, mode);
  playNote(7, 500, mode);
  playNote(7, 500, mode);
  playNote(7, 250, mode);
  playNote(10, 250, mode);
  playNote(9, 250, mode);
  playNote(7, 250, mode);
  playNote(5, 250, mode);
  playNote(12, 250, mode);
  playNote(7, 250, mode);
  playNote(9, 250, mode);
  playNote(5, 250, mode);
  delay(250);
 
  if(mode == 0) {
    mode = 1;
  } else if(mode == 1) {
    mode = 2;
  } else if(mode == 2) {
    mode = 3;
  } else if(mode == 3) {
    mode = 0;
  }
}

void buzz(int targetPin, long frequency, long length) {
  long delayValue = 1000000/frequency/2; // calculate the delay value between transitions
  //// 1 second's worth of microseconds, divided by the frequency, then split in half since
  //// there are two phases to each cycle
  long numCycles = frequency * length/ 1000; // calculate the number of cycles for proper timing
  //// multiply frequency, which is really cycles per second, by the number of seconds to
  //// get the total number of cycles to produce
  for (long i=0; i < numCycles; i++){ // for the calculated length of time...
    digitalWrite(targetPin,HIGH); // write the buzzer pin high to push out the diaphram
    delayMicroseconds(delayValue); // wait for the calculated delay value
    digitalWrite(targetPin,LOW); // write the buzzer pin low to pull back the diaphram
    delayMicroseconds(delayValue); // wait againf or the calculated delay value
  }
}