diff --git a/build/shared/dist/examples/Digital/StateChangeDetection/StateChangeDetection.pde b/build/shared/dist/examples/Digital/StateChangeDetection/StateChangeDetection.pde new file mode 100644 index 000000000..66fd7253b --- /dev/null +++ b/build/shared/dist/examples/Digital/StateChangeDetection/StateChangeDetection.pde @@ -0,0 +1,88 @@ +/* + State change detection (edge detection) + + Often, you don't need to know the state of a digital input all the time, + but you just need to know when the input changes from one state to another. + For example, you want to know when a button goes from OFF to ON. This is called + state change detection, or edge detection. + + This example shows how to detect when a button or button changes from off to on + and on to off. + + The circuit: + * pushbutton attached to pin 2 from +5V + * 10K resistor attached to pin 2 from ground + * LED attached from pin 13 to ground (or use the built-in resistor on + (most Arduino boards) + + created 27 Sep 2005 + modified 17 Jun 2009 + by Tom Igoe + + http://arduino.cc/en/Tutorial/ButtonStateChange + + */ + +// this constant won't change: +const int buttonPin = 2; // the pin that the pushbutton is attached to +const int ledPin = 13; // the pin that the LED is attached to + +// Variables will change: +int buttonPushCounter = 0; // counter for the number of button presses +int buttonState = 0; // current state of the button +int lastButtonState = 0; // previous state of the button + +void setup() { + // initialize the button pin as a input: + pinMode(buttonPin, INPUT); + // initialize serial communication: + Serial.begin(9600); +} + + +void loop() { + // read the pushbutton input pin: + buttonState = digitalRead(buttonPin); + + // compare the buttonState to its previous state + if (buttonState != lastButtonState) { + // if the state has changed, increment the counter + if (buttonState == HIGH) { + // if the current state is HIGH then the button + // wend from off to on: + buttonPushCounter++; + Serial.println("on"); + Serial.print("number of button pushes: "); + Serial.println(buttonPushCounter, DEC); + } + else { + // if the current state is LOW then the button + // wend from on to off: + Serial.println("off"); + } + + // save the current state as the last state, + //for next time through the loop + lastButtonState = buttonState; + } + + // turns on the LED every four button pushes by + // checking the modulo of the button push counter. + // the modulo function gives you the remainder of + // the division of two numbers: + if (buttonPushCounter % 4 == 0) { + digitalWrite(ledPin, HIGH); + } else { + digitalWrite(ledPin, LOW); + } + +} + + + + + + + + +