Reference Language | Libraries | Comparison | Changes
digitalRead()
Description
Reads the value from a specified digital pin, either HIGH or LOW.
Syntax
digitalRead(pin)
Parameters
pin: the number of the digital pin you want to read (int)
Returns
Example
Sets pin 13 to the same value as pin 7, declared as an input.
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
}
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
}
Note
If the pin isn't connected to anything, digitalRead() can return either HIGH or LOW (and this can change randomly).
The analog input pins can be used as digital pins, referred to as A0, A1, etc.
See also
Corrections, suggestions, and new documentation should be posted to the Forum.
The text of the Arduino reference is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.
Share
