aqui esta bons projectos com LDRS-photocells
(https://lusorobotica.com/proxy.php?request=http%3A%2F%2Fwww.adafruit.com%2Fadablog%2Fwp-content%2Fuploads%2F2009%2F05%2Fpt-1951.jpg&hash=4f19c518c138f49afc7c0ef670f352f266667ed2)
int photosensorPin = 0;
int piezoPin = 9;
int val = 0;
void setup() {
pinMode(piezoPin, OUTPUT);
}
void loop() {
digitalWrite(piezoPin, LOW);
val = analogRead(photosensorPin);
val = val/2;
for( int i=0; i<500; i++ ) { // play it for 50 cycles
digitalWrite(piezoPin, HIGH);
delayMicroseconds(val);
digitalWrite(piezoPin, LOW);
delayMicroseconds(val);
}
}
http://www.ladyada.net/learn/sensors/cds.html (http://www.ladyada.net/learn/sensors/cds.html)
um bom exemplo:
http://www.adafruit.com/blog/2009/05/19/piezo-with-an-arduino-photoresistor/ (http://www.adafruit.com/blog/2009/05/19/piezo-with-an-arduino-photoresistor/)
o video nao consegui colocar. :-\ :-\