/* * voltmeter.c: * Demonstrate use of the Gertboard A to D converter to make * a simple voltmeter. * * Copyright (c) 2012-2013 Gordon Henderson. *********************************************************************** * 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 . *********************************************************************** */ #include #include #include int main () { int x1, x2 ; double v1, v2 ; printf ("\n") ; printf ("Gertboard demo: Simple Voltmeters\n") ; printf ("=================================\n") ; // Always initialise wiringPi. Use wiringPiSys() if you don't need // (or want) to run as root wiringPiSetupSys () ; // Initialise the Gertboard analog hardware at pin 100 gertboardAnalogSetup (100) ; printf ("\n") ; printf ("| Channel 0 | Channel 1 |\n") ; for (;;) { // Read the 2 channels: x1 = analogRead (100) ; x2 = analogRead (101) ; // Convert to a voltage: v1 = (double)x1 / 1023.0 * 3.3 ; v2 = (double)x2 / 1023.0 * 3.3 ; // Print printf ("| %6.3f | %6.3f |\r", v1, v2) ; fflush (stdout) ; } return 0 ; }