digitalRead()

Reads the value from a specified digital pin, either HIGH or LOW.

Library Documentation

uint32 digitalRead(uint8 pin)

Read a digital value from a pin.

The pin must have its mode set to one of INPUT, INPUT_PULLUP, and INPUT_PULLDOWN.

Parameters:

• pin -

  Pin to read from.

Return:

LOW or HIGH.

See:

pinMode()

Discussion

If the pin isn’t connected to anything, digitalRead() can return either HIGH or LOW (and this will change in a way that seems random).

Example

The following example turns the LED on or off when the button is pressed:

void setup() {
  pinMode(BOARD_LED_PIN, OUTPUT);
  pinMode(BOARD_BUTTON_PIN, INPUT);
}

void loop() {
  int val = digitalRead(BOARD_BUTTON_PIN);   // reads the input pin
  togglePin(BOARD_LED_PIN, val);
}

Arduino Compatibility

The Maple version of digitalRead() is compatible with Arduino.

See Also

• BOARD_BUTTON_PIN
• isButtonPressed()
• pinMode()
• digitalWrite()
• togglePin()

License and Attribution

Portions of this page were adapted from the Arduino Reference Documentation, which is released under a Creative Commons Attribution-ShareAlike 3.0 License.