Keyboard Serial
A diferencia que el ejercicico "Haciendo música con un piezoeléctrico" (enlace), en el siguiente ejercicio se planteará la possibilidad de seleccionar el tono enviando carácteres ASCII, por el puerto serie.
The tones can be lauched using any program able of sending ascii values over the serial port. Terminal software packages, Processing, Pure Data, Director, or the serial proxy + Flash combination can be used to launch the tones.
Example of connection of a Piezo to pin 9
/* Keyboard Serial
* ----------------
*
* Program to play tones depending on the
* data coming from the serial port.
*
* The calculation of the tones is made following the mathematical
* operation:
*
* timeHigh = 1/(2 * toneFrequency) = period / 2
*
* where the different tones are described as in the table:
*
* note frequency period PW (timeHigh)
* c 261 Hz 3830 1915
* d 294 Hz 3400 1700
* e 329 Hz 3038 1519
* f 349 Hz 2864 1432
* g 392 Hz 2550 1275
* a 440 Hz 2272 1136
* b 493 Hz 2028 1014
* C 523 Hz 1912 956
*
* (cleft) 2005 D. Cuartielles for K3
*/
int ledPin = 13;
int speakerOut = 9;
byte names[] ={'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C'};
int tones[] = {1915, 1700, 1519, 1432, 1275, 1136, 1014, 956};
byte val = 0;
int serByte = -1;
int statePin = LOW;
int count = 0;
void setup() {
pinMode(ledPin, OUTPUT);
pinMode(speakerOut, OUTPUT);
beginSerial(9600);
}
void loop() {
digitalWrite(speakerOut, LOW);
serByte = serialRead();
if (serByte != -1) { !!!OJO funcion serialavailable ()¿?
val = serByte;
printByte(val);
statePin = !statePin;
digitalWrite(ledPin, statePin);
}
for (count=0;count<=8;count++) {
if (names[count] == val) {
digitalWrite(speakerOut, HIGH);
delayMicroseconds(tones[count]);
digitalWrite(speakerOut, LOW);
delayMicroseconds(tones[count]);
}
}
}