Práctica 11

/* Arduino + Buzzer + Photoresistor = Home-made Theremin
http://antoniolopes.info/wp/blog/2012/06/28/arduino-buzzer-photoresistor-home-made-theremin/
*/

int prPin = 0; // Pin where the photo resistor is connected to

int prReading; // The analog reading from the photoresistor

int buzzerPin = 4; // Connect Buzzer to Pin 4

long buzzerFreq; // The frequency to buzz the buzzer

// You can experiment with these values:
long BUZZ_FREQ_MAX = 2500; // Maximum frequency for the buzzer

long PR_MAX = 1023; // Maximum value for the photoresistor



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

}



void loop() {

    prReading = analogRead(prPin); // Values 0-1023

    buzzerFreq = (prReading * BUZZ_FREQ_MAX) / PR_MAX;

    buzz(buzzerPin, buzzerFreq, 10);

}



void buzz(int targetPin, long frequency, long length) {

    long delayValue = 1000000/frequency/2;

    long numCycles = frequency * length/ 1000;

    for (long i=0; i < numCycles; i++){

        digitalWrite(targetPin,HIGH);

        delayMicroseconds(delayValue);

        digitalWrite(targetPin,LOW);

        delayMicroseconds(delayValue);

    }

}

/* fin del codigo */