.. 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