digitalRead(pin)

What it does

Reads the value from a specified pin, it will be either HIGH or LOW.

Parameters

pin: the number of the pin you want to read. It has to be one of the digital pins of the board, thus it should be a number between 0 and 13. It could also be a variable representing a value in that range.

Returns

Either HIGH or LOW

Example

 
int ledPin = 13; // LED connected to digital pin 13
int inPin = 7;   // pushbutton connected to digital pin 7
int val = 0;     // variable to store the read value

void setup()
{
  pinMode(ledPin, OUTPUT);      // sets the digital pin 13 as output
  pinMode(inPin, INPUT);      // sets the digital pin 7 as input
}

void loop()
{
  val = digitalRead(inPin);   // read the input pin
  digitalWrite(ledPin, val);    // sets the LED to the button's value
}

Sets pin 13 to the same value as the pin 7, which is an input.

See also