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- /*
- Button
- Turns on and off a light emitting diode(LED) connected to digital pin 13,
- when pressing a pushbutton attached to pin 2 we ground the circuit and turn the LED on
- The circuit:
- - LED attached from pin 13 to ground through 220 ohm resistor
- - pushbutton attached to pin 2 from +5V
- - 10K resistor attached to pin 2 from +5V (pulled up resistor)
- - Note: on most Arduinos there is already an LED on the board
- attached to pin 13.
- */
- // constants won't change. They're used here to set pin numbers:
- const int buttonPin = 2; // the number of the pushbutton pin
- const int ledPin = 13; // the number of the LED pin
- // variables will change:
- int buttonState; // variable for reading the pushbutton status
- void setup() {
- Serial.begin(9600);
- // initialize the LED pin as an output:
- pinMode(ledPin, OUTPUT);
- // initialize the pushbutton pin as an input:
- pinMode(buttonPin, INPUT);
- }
- void loop() {
- // read the state of the pushbutton value:
- buttonState = digitalRead(buttonPin);
- Serial.print(buttonState);
- Serial.print("\n");
- // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
- if (buttonState == LOW) {
- // turn LED on:
- digitalWrite(ledPin, HIGH);
- } else {
- // turn LED off:
- digitalWrite(ledPin, LOW);
- }
- }
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