examples/q2w/volts.c

/*
 * volts.c:
 *	Read in all 4 analogs on the Q2W analog board.
 *
 * 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 <stdio.h>
#include <wiringPi.h>
#include <pcf8591.h>

#define	LED		1
#define Q2W_ABASE       120

int main (void)
{
  int value, pin ;

// Enable the on-goard GPIO

  wiringPiSetup () ;

  pinMode (LED, OUTPUT) ;	// On-board LED

// Add in the pcf8591 on the q2w board

  pcf8591Setup (Q2W_ABASE, 0x48) ;

  printf ("Raspberry Pi - Quick2Wire Voltmeter\n") ;

  for (;;)
  {
    for (pin = 0 ; pin < 4 ; ++pin)
    {
      value = analogRead  (Q2W_ABASE + pin) ;
      printf ("  %5.2f", (double)value * 3.3 / 255.0) ;
    }
    printf ("\r") ; fflush (stdout) ;

    delay (100) ;
    digitalWrite (LED, !digitalRead (LED)) ;	// Flicker the LED
  }

  return 0 ;
}