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53 lines
1.5 KiB
Plaintext
53 lines
1.5 KiB
Plaintext
/* Debounce
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*
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* Each time the input pin goes from LOW to HIGH (e.g. because of a push-button
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* press), the output pin is toggled from LOW to HIGH or HIGH to LOW. There's
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* a minimum delay between toggles to debounce the circuit (i.e. to ignore
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* noise).
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*
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* David A. Mellis
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* 21 November 2006
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*
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* http://www.arduino.cc/en/Tutorial/Debounce
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*/
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int inPin = 7; // the number of the input pin
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int outPin = 13; // the number of the output pin
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int state = HIGH; // the current state of the output pin
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int reading; // the current reading from the input pin
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int previous = LOW; // the previous reading from the input pin
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// the follow variables are long's because the time, measured in miliseconds,
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// will quickly become a bigger number than can be stored in an int.
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long time = 0; // the last time the output pin was toggled
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long debounce = 200; // the debounce time, increase if the output flickers
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void setup()
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{
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pinMode(inPin, INPUT);
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pinMode(outPin, OUTPUT);
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}
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void loop()
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{
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reading = digitalRead(inPin);
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// if we just pressed the button (i.e. the input went from LOW to HIGH),
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// and we've waited long enough since the last press to ignore any noise...
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if (reading == HIGH && previous == LOW && millis() - time > debounce) {
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// ... invert the output
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if (state == HIGH)
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state = LOW;
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else
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state = HIGH;
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// ... and remember when the last button press was
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time = millis();
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}
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digitalWrite(outPin, state);
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previous = reading;
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}
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