Controlling LED with a Push Button using Arduino UNO | Tutorial | DIY Project

Controlling LED with a Push Button using Arduino 

In this tutorial we will learn how to detect the state of a button, and then toggle the state of the LED based on the state of the button.

Components Required:

- 1 * Arduino UNO 

- 1 * USB Cable 

- 1 * Button 

- 1 * LED 

- 1 * 10kΩ Resistor 

- 1 * 220Ω Resistor 

- 1 * Breadboard 

- Several jumpers wire

Circuit Diagram:

 

Procedure:

1. Make the connections according to the circuit diagram.

2. Connect your Arduino UNO to PC.

3. Upload the code provided to the board using Arduino IDE.

4. Enjoy playing with LED.

 

Code:

int ledpin=11;                                              //definition digital 11 pins as pin to control the LED
int btnpin=2;                                              //Set the digital 2 to button interface
volatile int state = LOW;                           // Defined output status LED Interface
void setup()
{
  pinMode(ledpin,OUTPUT);                         //Set digital 11 port mode, the OUTPUT for the output
  pinMode(btnpin,INPUT);                            //Set digital 2 port mode, the INPUT for the input
}
void loop()
{
  if(digitalRead(btnpin)==LOW)                          //Detection button interface to low
  {   
      delay(10);                                                //Delay 10ms for the elimination of key leading-edge jitter
      if(digitalRead(btnpin)==LOW)                          //Confirm button is pressed
      {     
        while(digitalRead(btnpin)==LOW);                //Wait for key interfaces to high
        delay(10);                                           //delay 10ms for the elimination of key trailing-edge jitter
        while(digitalRead(btnpin)==LOW);        //Confirm button release
        state = !state;            //Negate operation, each time you run the program here, state 

                                   // the HIGH becomes LOW, or the state becomes the LOW HIGH.
        digitalWrite(ledpin,state);     //Output control status LED, ON or OFF
      }
   }
}