Arduino push button led tutorial

Description: -

In this tutorial, we have to control LED with a button with the help Arduino Uno.

A push button is used to controlling some aspect of a machine. When we press the button, the LED is on (Arduino read it HIGH) and when we pressed again the led if off (Arduino read it LOW).

Requirement:

           1.    Arduino Uno.     
     2.   1 x 220 ohms Resistor.
     3.   1 x 10k ohms Resistor.
     4.   1 x LEDs (5mm).
     5.    Push button.
     6.    Breadboard.
     7.    Jumper wire.   

   

Step:-

1. A push button having 4 pins and we use 3 pins of the push button for controlling LED.

2. Connecting Button pin 4 to Arduino pin 5v using a jumper wire.

3. Attach a 10k ohms resistor to button pin 2 and at the end of the resistor is connected to Arduino pin GND.

4. Button pin 1 is connected to Arduino digital pin 4 using a jumper wire.

5. Attach a 220 ohms resistor to the positive pin (anode) of led and at the end of the resistor is connected to Arduino digital pin 2.

6. Connecting Negative pin of the LED to Arduino pin GND using a jumper wire.

7. Now the circuit is ready.....upload the code and enjoy it.....

Circuit:-

Code:-

// constants won't change. They're used here to set pin numbers:

const int buttonPin = 2;     // the number of the pushbutton pin

const int ledPin =  13;      // the number of the LED pin

// variables will change:

int buttonState = 0;         // variable for reading the pushbutton status

void setup() {

  Serial.begin(9600);

  // initialize the LED pin as an output:

  pinMode(ledPin, OUTPUT);

  // initialize the pushbutton pin as an input:

  pinMode(buttonPin, INPUT);

}

void loop() {

  // read the state of the pushbutton value:

  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:

  if (buttonState == HIGH) {

    // turn LED on:

    digitalWrite(ledPin, HIGH);

    Serial.println("Button is pressed");

  } else {

    // turn LED off:

    digitalWrite(ledPin, LOW);

    Serial.println("Button is not press");

  }

}

Control a 3 LED with a Button.

We have to control 3 LED with a Push button with the help Arduino Uno.

Requirement:-

   1.   Arduino Uno.

     2.   3 x 220 ohms Resistor. 

     3.   1 x 10k ohms Resistor.

     4.   3 x LEDs (5mm).

     5.   Push button.

     6.   Breadboard.

 7.   Jumper wire.  

Circuit:-

 Code: -

// constants won't change. They're used here to set pin numbers:

const int buttonPin =  4;     // the number of the pushbutton pin

const int ledPin        = 13;      // the number of the LED pin

const int ledPin1      = 12;

const int ledPin2      = 11;

// variables will change:

int  initial    = 0;       //hold current  initial

int oldstate    = 0;       //hold last  initial

int buttonstate = 0;      // variable for reading the pushbutton status

void setup() {

  pinMode(ledPin, OUTPUT);   // initialize the LED pin as an output:

  pinMode(ledPin1, OUTPUT);

  pinMode(ledPin2, OUTPUT);

  pinMode(buttonPin, INPUT); // initialize the pushbutton pin as an input:

}

void loop(){

  //debouncing routline to read button

  buttonstate = digitalRead(buttonPin);  //state the  initial of button

  if(buttonstate == HIGH){               //check if it has been pressed 

    delay(50);

    buttonstate = digitalRead(buttonPin);//state button again

    if(buttonstate == LOW){              //if it is 0 considered one press

     initial = oldstate + 1;        //increase  initial by 1

    }

  }else{                          //check if it has been NOT pressed

      delay(100);

      }

   switch (initial){               //react to button press a  initial

     case 1:                     //if  initial is 1

       digitalWrite(ledPin, HIGH);//on

       digitalWrite(ledPin1, LOW);//off

       digitalWrite(ledPin2, LOW);//off

       oldstate =  initial;               //set oldstate  initial as current  initial

       break;

     case 2:

       digitalWrite(ledPin, LOW);

       digitalWrite(ledPin1, HIGH);

       digitalWrite(ledPin2, LOW);

       oldstate =  initial;

       break;

     case 3:

       digitalWrite(ledPin, LOW);

       digitalWrite(ledPin1, LOW);

       digitalWrite(ledPin2, HIGH);

       oldstate =  initial;

       break;         

     default:                      //if  initial is not 1 2 3

       digitalWrite(ledPin, LOW);  //off

       digitalWrite(ledPin1, LOW);

       digitalWrite(ledPin2, LOW);

       oldstate = 0;                    //reset to all off/initial 0

       break;         

     }

}

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