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.. highlight:: cpp
.. _lang-digitalread:
digitalRead()
=============
Reads the value from a specified digital pin, either :ref:`HIGH
<lang-constants-high>` or :ref:`LOW <lang-constants-low>`.
Library Documentation
---------------------
.. doxygenfunction:: digitalRead
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
--------
- :ref:`BOARD_BUTTON_PIN <lang-board-values-but>`
- :ref:`lang-isButtonPressed`
- :ref:`lang-pinmode`
- :ref:`lang-digitalWrite`
- :ref:`lang-togglepin`
.. include:: /arduino-cc-attribution.txt
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