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+.. _arduino-digitalwrite:
+
+digitalWrite()
+==============
+
+Description
+-----------
+
+Write a `HIGH <http://arduino.cc/en/Reference/Constants>`_ or a
+`LOW <http://arduino.cc/en/Reference/Constants>`_ value to a
+digital pin.
+
+
+
+If the pin has been configured as an OUTPUT with
+`pinMode <http://arduino.cc/en/Reference/PinMode>`_\ (), its voltage
+will be set to the corresponding value: 5V (or 3.3V on 3.3V boards)
+for HIGH, 0V (ground) for LOW.
+
+
+
+If the pin is configured as an INPUT, writing a HIGH value with
+digitalWrite() will enable an internal 20K pullup resistor (see the
+`tutorial on digital pins <http://arduino.cc/en/Tutorial/DigitalPins>`_).
+Writing LOW will disable the pullup. The pullup resistor is enough
+to light an LED dimly, so if LEDs appear to work, but very dimly,
+this is a likely cause. The remedy is to set the pin to an output
+with the pinMode() function.
+
+
+
+**NOTE:** Digital pin 13 is harder to use as a digital input than
+the other digital pins because it has an LED and resistor attached
+to it that's soldered to the board on most boards. If you enable
+its internal 20k pull-up resistor, it will hang at around 1.7 V
+instead of the expected 5V because the onboard LED and series
+resistor pull the voltage level down, meaning it always returns
+LOW. If you must use pin 13 as a digital input, use an external
+pull down resistor.
+
+
+
+Syntax
+------
+
+digitalWrite(pin, value)
+
+
+
+Parameters
+----------
+
+pin: the pin number
+
+
+
+value: `HIGH <http://arduino.cc/en/Reference/Constants>`_ or
+`LOW <http://arduino.cc/en/Reference/Constants>`_
+
+
+
+Returns
+-------
+
+none
+
+
+
+Example
+-------
+
+::
+
+     
+    int ledPin = 13;                 // LED connected to digital pin 13
+    
+    void setup()
+    {
+      pinMode(ledPin, OUTPUT);      // sets the digital pin as output
+    }
+    
+    void loop()
+    {
+      digitalWrite(ledPin, HIGH);   // sets the LED on
+      delay(1000);                  // waits for a second
+      digitalWrite(ledPin, LOW);    // sets the LED off
+      delay(1000);                  // waits for a second
+    }
+
+
+
+Sets pin 13 to HIGH, makes a one-second-long delay, and sets the
+pin back to LOW.
+
+
+
+Note
+----
+
+The analog input pins can be used as digital pins, referred to as
+A0, A1, etc.
+
+
+
+See also
+--------
+
+
+-  `pinMode <http://arduino.cc/en/Reference/PinMode>`_\ ()
+-  `digitalRead <http://arduino.cc/en/Reference/DigitalRead>`_\ ()
+-  `Tutorial: Digital Pins <http://arduino.cc/en/Tutorial/DigitalPins>`_
+
+