SeeedStudio Grove Series - Page 22

/* set buzzer pin as output */
pinMode(BUZZER_PIN, OUTPUT);
}
void loop()
{
for(int i = 0; i < length; i++) {
if(notes[i] == ' ') {
delay(beats[i] * tempo);
} else {
playNote(notes[i], beats[i] * tempo);
}
delay(tempo / 2); /* delay between notes */
}
}
/* play tone */
void playTone(int tone, int duration) {
for (long i = 0; i < duration * 1000L; i += tone * 2) {
digitalWrite(BUZZER_PIN, HIGH);
delayMicroseconds(tone);
digitalWrite(BUZZER_PIN, LOW);
delayMicroseconds(tone);
}
}
void playNote(char note, int duration) {
char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C' };
int tones[] = { 1915, 1700, 1519, 1432, 1275, 1136, 1014, 956 };
// play the tone corresponding to the note name
for (int i = 0; i < 8; i++) {
if (names[i] == note) {
playTone(tones[i], duration);
}
}
}
RESULT
Your LaunchPad will play music! “Twinkle Twinkle Little Star” or “The Alphabet Song”
TIPS
The calculation of the tones is made using the mathematical operation:
timeHigh = period / 2 = 1 / (2 * toneFrequency)
Where the different tones are described as in the table below: