Im einem vorherigen Experiment wurde der Piezo-Wandler als Sensor benutzt. Hier verwenden wir ihn als Tongenerator.
int PIEZO_PIN = 13;
int BUTTON_PIN = 12;
const int TONE_FREQUENCY = 443; // in Hz
void setup()
{
pinMode(PIEZO_PIN, OUTPUT);
pinMode(BUTTON_PIN, INPUT);
}
void loop()
{
if (digitalRead(BUTTON_PIN) == LOW) {
tone(PIEZO_PIN, TONE_FREQUENCY);
} else {
noTone(PIEZO_PIN);
}
}Hier wird eine Melodie durch eine Folge von Tönen erzeugt. In diesem Beispiel wird die Hauptmelodie des Songs "Popcorn" von Gershon Kingsley (1969) verwendet.
#define NOTE_B0 31
#define NOTE_C1 33
#define NOTE_CS1 35
#define NOTE_D1 37
#define NOTE_DS1 39
#define NOTE_E1 41
#define NOTE_F1 44
#define NOTE_FS1 46
#define NOTE_G1 49
#define NOTE_GS1 52
#define NOTE_A1 55
#define NOTE_AS1 58
#define NOTE_B1 62
#define NOTE_C2 65
#define NOTE_CS2 69
#define NOTE_D2 73
#define NOTE_DS2 78
#define NOTE_E2 82
#define NOTE_F2 87
#define NOTE_FS2 93
#define NOTE_G2 98
#define NOTE_GS2 104
#define NOTE_A2 110
#define NOTE_AS2 117
#define NOTE_B2 123
#define NOTE_C3 131
#define NOTE_CS3 139
#define NOTE_D3 147
#define NOTE_DS3 156
#define NOTE_E3 165
#define NOTE_F3 175
#define NOTE_FS3 185
#define NOTE_G3 196
#define NOTE_GS3 208
#define NOTE_A3 220
#define NOTE_AS3 233
#define NOTE_B3 247
#define NOTE_C4 262
#define NOTE_CS4 277
#define NOTE_D4 294
#define NOTE_DS4 311
#define NOTE_E4 330
#define NOTE_F4 349
#define NOTE_FS4 370
#define NOTE_G4 392
#define NOTE_GS4 415
#define NOTE_A4 440
#define NOTE_AS4 466
#define NOTE_B4 494
#define NOTE_C5 523
#define NOTE_CS5 554
#define NOTE_D5 587
#define NOTE_DS5 622
#define NOTE_E5 659
#define NOTE_F5 698
#define NOTE_FS5 740
#define NOTE_G5 784
#define NOTE_GS5 831
#define NOTE_A5 880
#define NOTE_AS5 932
#define NOTE_B5 988
#define NOTE_C6 1047
#define NOTE_CS6 1109
#define NOTE_D6 1175
#define NOTE_DS6 1245
#define NOTE_E6 1319
#define NOTE_F6 1397
#define NOTE_FS6 1480
#define NOTE_G6 1568
#define NOTE_GS6 1661
#define NOTE_A6 1760
#define NOTE_AS6 1865
#define NOTE_B6 1976
#define NOTE_C7 2093
#define NOTE_CS7 2217
#define NOTE_D7 2349
#define NOTE_DS7 2489
#define NOTE_E7 2637
#define NOTE_F7 2794
#define NOTE_FS7 2960
#define NOTE_G7 3136
#define NOTE_GS7 3322
#define NOTE_A7 3520
#define NOTE_AS7 3729
#define NOTE_B7 3951
#define NOTE_C8 4186
#define NOTE_CS8 4435
#define NOTE_D8 4699
#define NOTE_DS8 4978
const int REST = 0;
const int PIEZO_PIN = 13;
// Tune from "Gorilla.bas"
/*
int tune[] = {NOTE_C4, NOTE_D4, NOTE_E4, NOTE_D4, NOTE_C4, NOTE_D4, NOTE_E4, NOTE_C4, NOTE_C4, REST, REST, REST};
int beats[] = { 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1};
int tunelength = 12;
int tempo = 170;
*/
// Tune from "Popcorn" composed by Gershon Kingsley (1969)
int tune[] = {
NOTE_C5, NOTE_AS4, NOTE_C5, NOTE_G4, NOTE_DS4, NOTE_G4, NOTE_C4, REST,
NOTE_C5, NOTE_AS4, NOTE_C5, NOTE_G4, NOTE_DS4, NOTE_G4, NOTE_C4, REST,
NOTE_C5, NOTE_D5, NOTE_DS5, NOTE_D5, NOTE_DS5, NOTE_C5, NOTE_D5, NOTE_C5,
NOTE_D5, NOTE_AS4, NOTE_C5, NOTE_AS4, NOTE_C5, NOTE_GS4, NOTE_C5, REST,
NOTE_C6, NOTE_AS5, NOTE_C6, NOTE_G5, NOTE_DS5, NOTE_G5, NOTE_C5, REST,
NOTE_C6, NOTE_AS5, NOTE_C6, NOTE_G5, NOTE_DS5, NOTE_G5, NOTE_C5, REST,
NOTE_C6, NOTE_D6, NOTE_DS6, NOTE_D6, NOTE_DS6, NOTE_C6, NOTE_D6, NOTE_C6,
NOTE_D6, NOTE_AS5, NOTE_C6, NOTE_AS5, NOTE_C6, NOTE_GS5, NOTE_C6, REST
};
int beats[] = {
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1
};
int tunelength = 64;
int tempo = 190;
int repeats = 1;
void setup()
{
pinMode(PIEZO_PIN, OUTPUT);
}
void loop()
{
if (repeats > 0) {
for (int i =0; i<tunelength; i++) {
if (tune[i]==REST) {
noTone(PIEZO_PIN);
} else {
tone(PIEZO_PIN, tune[i], beats[i]*tempo);
}
delay(beats[i]*tempo);
delay(tempo/10);
}
repeats--;
} else {
while(true) {}
}
}In dem Video Teardown of a big HEPA air filter unit von BigClive wird eine interessante Technik gezeigt, wie man den Klang eines Piezos nachklingen lassen kann.
#define PIN_LOAD 8
#define PIN_PIEZO 9
#define PIN_POTI_LOAD A0
#define PIN_POTI_PIEZO A1
int delayLoad = 100;
int delayPiezo = 300;
void setup()
{
Serial.begin(9600);
pinMode(PIN_LOAD, OUTPUT);
pinMode(PIN_PIEZO, OUTPUT);
pinMode(PIN_POTI_LOAD, INPUT);
pinMode(PIN_POTI_PIEZO, INPUT);
}
void loop()
{
playBing(800);
playBing(1200);
playBing(2400);
playBing(3600);
delayLoad = analogRead(PIN_POTI_LOAD);
delayPiezo = analogRead(PIN_POTI_PIEZO);
Serial.println("delayLoad=" + String(delayLoad));
Serial.println("delayPiezo=" + String(delayPiezo) + "\n");
delay(1000);
}
void playBing(int freq)
{
digitalWrite(PIN_LOAD, LOW);
delay(delayLoad);
digitalWrite(PIN_LOAD, HIGH);
tone(PIN_PIEZO, freq);
delay(delayPiezo);
noTone(PIN_PIEZO);
}
Piezo-Töne ohne Nachklang (39kB):
Piezo-Töne mit Nachklang (89kB):