C Example: Digital Inputs

  Program to display

  // Program to display push-button input as LED output

  // First include header file with definitions for specific PIC.
  // Set fuses.  HS is type of external clock, low voltage protection
  // (LVP) is off, and the watchdog timer (WDT) is off.
  // External clock frequency of 20 MHz is specified.

  #include <18f4520.h>
  #fuses HS,NOLVP,NOWDT
  #use delay (clock=20000000)

  // Define pin names to be used in the main program. See header file
  // for currently defined pin names.

  #define IN0 PIN_B0
  #define IN1 PIN_B1
  #define IN2 PIN_B2
  #define OUT0 PIN_D0
  #define OUT1 PIN_D1
  #define OUT2 PIN_D2

  // Begin main body of program.

  void main(void) {

  // Use while to set up infinite loop.

     while(TRUE){

     // Check each input pin and define action to be taken depending on
     // reading from input (in this case, set the output to the input).

        if(input(IN0))
           output_high(OUT0);
        else if (!input(IN0))
           output_low(OUT0);

        if(input(IN1))
           output_high(OUT1);
        else if (!input(IN1))
           output_low(OUT1);

        if(input(IN2))
           output_high(OUT2);
        else if (!input(IN2))
           output_low(OUT2);}
  }