Arduino : 3 Different Ways of Connecting a Push Button

Introduction

In this chapter, we are going to learn the three different way of connecting a push button with Arduino microcontroller.

3 Ways

• Internal pull-up resistor
• External pull-up resistor
• External pull-down resistor

Internal Pull-Up Resistor

 

• Connect the push button with Arduino as shown in the circut ie,
• Connect one terminal of the push button to any digital pin of Arduino in my case I'm using digital pin D5
• Then connect the other terminal of the push button to the ground of Arduino.
• Now upload the below code.

#define button 5
boolean buttonState;
void setup()
{
 pinMode(button,INPUT_PULLUP);
 Serial.begin(9600);
}
void loop()
{
 buttonState = digitalRead(button);
 Serial.println(buttonState);
}

Result

• By default, the pin state will be HIGH.
• When we press the push button the pin state will change to LOW.

External Pull-Up Resistor

 

• Connect one of the terminal of the push button to any digital pin of Arduino, in my case I have used digital pin 5.
• Connect the other terminal of the push button to the ground of Arduino.
• Then connect a resistor of value 10 Kohms from the digital pin which you have connected the push button to the 5v of Arduino, in my case I have connected the resistor form digital pin 5 to 5v.
• Now upload the below program.

#define button 5
boolean buttonState;
void setup() {
pinMode(button,INPUT);digitalWrite(button,LOW);
Serial.begin(9600);
}
void loop() {
buttonState = digitalRead(button);
Serial.println(buttonState);
}

Result

• By default, the pin state will be HIGH
• When I press the push button the state will change to LOW.

External Pull-Down Resistor

 

• Connect one of the terminal of the push button to any digital pin of Arduino, in my case I have used digital pin 5.
• Then connect the other terminal to the 5v of Arduino.
• Then connect a resistor of value 10 Kohms from the digital pin which you have connected the push button to the ground of Arduino, in my case I have connected the resistor form digital pin 5 to ground.
• Now upload the below code.

#define button 5
boolean buttonState;
void setup() {
pinMode(button,INPUT);
Serial.begin(9600);
}
void loop() {
 buttonState = digitalRead(button);
 Serial.println(buttonState);
}

Result

• By default, the pin state will be LOW
• When we press the push button the state will change to HIGH from LOW

Video