Introduction
- Programming functions for the Arduino Uno
- Switches
- Push-buttons
- Example
(30 minutes)
Example
The example uses the built-in LED (connected to pin 13) and a push-button connected to pin 7. The LED lights up while the push-button is pressed.
The code:
/* https://www.arduino.cc/en/tutorial/pushbutton
* Basic Digital Read
* ------------------
*
* turns on and off a light emitting diode(LED) connected to digital
* pin 13, when pressing a pushbutton attached to pin 7. It illustrates the
* concept of Active-Low, which consists in connecting buttons using a
* 1K to 10K pull-up resistor.
*
* Created 1 December 2005
* copyleft 2005 DojoDave <http://www.0j0.org>
*
*/
int ledPin = 13; // choose the pin for the LED
int inPin = 7; // choose the input pin (for a pushbutton)
int val = 0; // variable for reading the pin status
void setup() {
pinMode(ledPin, OUTPUT); // declare LED as output
pinMode(inPin, INPUT); // declare pushbutton as input
}
void loop(){
val = digitalRead(inPin); // read input value
if (val == HIGH) { // check if the input is HIGH (button released)
digitalWrite(ledPin, LOW); // turn LED OFF
}
else {
digitalWrite(ledPin, HIGH); // turn LED ON
}
}
source 1