Add Content Functions/Digital IO

Author: Akshay Sharma

Language/Functions/Digital IO/digitalRead.adoc

@@ -0,0 +1,87 @@
+:source-highlighter: pygments
+:pygments-style: arduino
+//:ext-relative: adoc
+:ext-relative: .html
+
+= digitalRead()
+
+
+// OVERVIEW SECTION STARTS
+[#overview]
+--
+
+[float]
+=== Description
+Reads the value from a specified digital pin, either `HIGH` or `LOW`.
+[%hardbreaks]
+
+
+[float]
+=== Syntax
+`digitalRead(pin)`
+
+
+[float]
+=== Parameters
+
+
+[float]
+=== Returns
+`HIGH` or `LOW`
+
+--
+// OVERVIEW SECTION ENDS
+
+
+
+
+// HOW TO USE SECTION STARTS
+[#howtouse]
+--
+
+[float]
+=== Example Code
+// Describe what the example code is all about and add relevant code   ►►►►► THIS SECTION IS MANDATORY ◄◄◄◄◄
+Sets pin 13 to the same value as pin 7, declared as an input.
+
+//[source,arduino]
+----
+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
+}
+----
+[%hardbreaks]
+
+[float]
+=== Notes and Warnings
+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.
+[%hardbreaks]
+
+[float]
+=== See also
+// Link relevant content by category, such as other Reference terms (please add the tag #LANGUAGE#),
+// definitions (please add the tag #DEFINITION#), and examples of Projects and Tutorials
+// (please add the tag #EXAMPLE#)  ►►►►► THIS SECTION IS MANDATORY ◄◄◄◄◄
+[role="language"]
+* #LANGUAGE# link:pinMode{ext-relative}[pinMode()] +
+* #LANGUAGE# link:digitalWrite{ext-relative}[digitalWrite()]
+
+[role="example"]
+* #EXAMPLE# Tutorial: (http://arduino.cc/en/Tutorial/DigitalPins[Digital Pins])
+
+--
+// HOW TO USE SECTION ENDS