Arduino Tutorial 27: Understanding Pushbuttons and Pull Up and Pull Down Resistors

Being able to add push buttons to your projects adds important new capabilities to your prototypes. It is a clever way you can get input from a user. You could imagine using push buttons to turn something on or off, or they could be used to set motor speed or direction. In order to incorporate buttons into a project, you need to understand the concept of pull up and pull down resistors. In this tutorial we show you how to include buttons in a project, by demonstrating a simple on/off function on an LED.

If you want to follow along at home, you can order the Arduino Kit we are using HERE.

This is the code we used in this project to switch the LED on and off.

int LEDPin=8;
int buttonPin=12;
int buttonRead;
int dt=100;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(LEDPin, OUTPUT);
pinMode(buttonPin, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
buttonRead=digitalRead(buttonPin);
Serial.println(buttonRead);
delay(dt);
if(buttonRead==1){
  digitalWrite(LEDPin,LOW);
}
if(buttonRead==0){
  digitalWrite(LEDPin, HIGH);
}

}

int LEDPin=8;

int buttonPin=12;

int buttonRead;

int dt=100;

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

pinMode(LEDPin, OUTPUT);

pinMode(buttonPin, INPUT);

}

void loop() {

// put your main code here, to run repeatedly:

buttonRead=digitalRead(buttonPin);

Serial.println(buttonRead);

delay(dt);

if(buttonRead==1){

digitalWrite(LEDPin,LOW);

}

if(buttonRead==0){

digitalWrite(LEDPin, HIGH);

}

Making The World a Better Place One High Tech Project at a Time. Enjoy!