DIGITAL INPUTS

In this project, we will try to control the LED using two push buttons by reading the current status of the button.

THE PUSH BUTTON:

Fig: PUSH BUTTON

The working of a push button is clearly understood by the picture beside. Pins A, C and B,D are internally connected. When the button is pressed, all the four pins get connected.

BREADBOARD LAYOUT:

Fig: Breadboard layout
Created using Fritzing

Pressing the top button will turn on LED and pressing the bottom button will turn it off.

NEW CODING TERMS:

• INPUT_PULLUP : This is the mode of pin (similar to OUTPUT mode). It simply means that the pin is in INPUT mode and initialized to HIGH
• digitalRead(pinnum) : reads the digital value (ON/OFF) of the pin "pinnum"

CODE:

int ledPin = 5;
int buttonApin = 9;
int buttonBpin = 8;

void setup() 
{
  pinMode(ledPin, OUTPUT);
  pinMode(buttonApin, INPUT_PULLUP);  
  pinMode(buttonBpin, INPUT_PULLUP);  
}

void loop() 
{
  if (digitalRead(buttonApin) == LOW)
  {
    digitalWrite(ledPin, HIGH);
  }
  if (digitalRead(buttonBpin) == LOW)
  {
    digitalWrite(ledPin, LOW);
  }
}