Arduino Turn LED On And Off with Button or Switch Control Digital Input with digitalRead Function

Arduino Turn LED On And Off With Button

Controlling a LED with button is one of important learning because it cover “How to take digital input”. Second learning is if decision logic application.

Arduino Turn LED On And Off With Button code uses three main functions digitalWrite, digitalRead and pinMode. Digital input pins are used to interface the switch and LED for control on and off.

To implement this experiment you have to interface switch or button with Arduino on pin number 12 and we use build-in LED on pin number 13.

/*
	Arduino LED Control With Switch 
	https://elextutorial.com
	Turns on LED by pressing a switch or button. 
*/

void setup() 
{  
	pinMode(13, OUTPUT);	// set pin 13 as an output, the pin having onboard LED.
	pinMode(12, INPUT);	// set pin 12 as an input.
}

void loop() 
{
	int x = digitalRead(12); // read the pin number 12
	if( x == 1)
	{
		digitalWrite(13, HIGH); // turn the pin 13 HIGH means on (set)
	}else
	{
		digitalWrite(13, LOW); // turn the pin 13 LOW means off (reset)
	}
	delay(100); // delay for 100 milli second
}
				 

Arduino pinMode Function

All the digital pins can be used as input or output in Arduino. And we have to set the pin 13 into output mode and pin 12 into input mode with the help of pinMode function.

Arduino Digital Input with digitalRead Function

Arduino library have a function called digitalWrite and this function is used to read the pin. This function is used to take the digital input.

digitalWrite() function return a boolean value based on the state of the pin. If the pin is set to +5 volt it will read HIGH otherwise read LOW.

Arduino Digital Switch Interfacing

Interfacing a switch or button with Arduino is little bit tricky and involve some circuit making.

The figure 1 below shows the circuit diagram of switch interfacing. When the switch is not pressed the pin will read as 1, because the current flows from vcc to resistance. In case when switch is pressed the pin will read as 0, because switch is short circuit to ground.

The figure 2 below shows the circuit diagram of switch interfacing with Arduino on breadboard.

Switch Interfacing and Concept of the Pullup Resistance

The resistance connected with switch is known as pullup resistance, because it provide the current to the device to read high or 1. The “LOW” to “HIGH” logic transition of digital signal is known as “PULL UP” action and “HIGH” to “LOW” logic transition of digital signal is known as “PULL DOWN” action.

/*
	Arduino LED Control With Switch 
	https://elextutorial.com
	
*/

void setup() 
{  
	pinMode(13, OUTPUT);	// set pin 13 as an output, the pin having onboard LED.
	pinMode(12, INPUT);	// set pin 12 as an input.
}

void loop() 
{
	int x = digitalRead(12); // read the pin number 12
	digitalWrite(13, x); // turn the pin HIGH / LOW based on x
	delay(100); // delay for 100 milli second
}