text: /*
   * piFace.c:
   *	Simple test for the PiFace interface board.
   *
   *	Read the buttons and output the same to the LEDs
   *
   * Copyright (c) 2012-2013 Gordon Henderson. <projects@drogon.net>
   ***********************************************************************
   * This file is part of wiringPi:
   *	https://projects.drogon.net/raspberry-pi/wiringpi/
   *
   *    wiringPi is free software: you can redistribute it and/or modify
   *    it under the terms of the GNU Lesser General Public License as published by
   *    the Free Software Foundation, either version 3 of the License, or
   *    (at your option) any later version.
   *
   *    wiringPi is distributed in the hope that it will be useful,
   *    but WITHOUT ANY WARRANTY; without even the implied warranty of
   *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *    GNU Lesser General Public License for more details.
   *
   *    You should have received a copy of the GNU Lesser General Public License
   *    along with wiringPi.  If not, see <http://www.gnu.org/licenses/>.
   ***********************************************************************
   */
  
  #include <wiringPi.h>
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <stdint.h>
  
  int outputs [4] = { 0,0,0,0 } ;
  
  void scanButton (int button)
  {
    if (digitalRead (button) == LOW)
    {
      outputs [button] ^= 1 ;
      digitalWrite (button, outputs [button]) ;
    }
  
    while (digitalRead (button) == LOW)
      delay (1) ;
  }
  
  
  int main (void)
  {
    int pin, button ;
  
    printf ("Raspberry Pi wiringPiFace test program\n") ;
  
    if (wiringPiSetupPiFace () == -1)
      exit (1) ;
  
  // Enable internal pull-ups
  
    for (pin = 0 ; pin < 8 ; ++pin)
      pullUpDnControl (pin, PUD_UP) ;
  
  
    for (;;)
    {
      for (button = 0 ; button < 4 ; ++button)
        scanButton (button) ;
      delay (1) ;
    }
  
    return 0 ;
  }
  