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diff --git a/source/arduino/digitalread.rst b/source/arduino/digitalread.rst new file mode 100644 index 0000000..ec64fb0 --- /dev/null +++ b/source/arduino/digitalread.rst @@ -0,0 +1,86 @@ +.. _arduino-digitalread: + +digitalRead() +============= + +Description +----------- + +Reads the value from a specified digital pin, either +`HIGH <http://arduino.cc/en/Reference/Constants>`_ or +`LOW <http://arduino.cc/en/Reference/Constants>`_. + + + +Syntax +------ + +digitalRead(pin) + + + +Parameters +---------- + +pin: the number of the digital pin you want to read (*int*) + + + +Returns +------- + +`HIGH <http://arduino.cc/en/Reference/Constants>`_ or +`LOW <http://arduino.cc/en/Reference/Constants>`_ + + + +Example +------- + +:: + + + 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 + } + + + +Sets pin 13 to the same value as the pin 7, which is an input. + + + +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 +-------- + + +- `pinMode <http://arduino.cc/en/Reference/PinMode>`_\ () +- `digitalWrite <http://arduino.cc/en/Reference/DigitalWrite>`_\ () +- `Tutorial: Digital Pins <http://arduino.cc/en/Tutorial/DigitalPins>`_ + + |