/* * buttons.c: * Simple test for the PiFace interface board. * * Read the buttons and output the same to the LEDs * * 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 outputs [4] = { 0,0,0,0 } ; // Use 200 as the pin-base for the PiFace board #define PIFACE_BASE 200 /* * scanButton: * Read the guiven button - if it's pressed, then flip the state * of the correspoinding output pin ********************************************************************************* */ void scanButton (int button) { if (digitalRead (PIFACE_BASE + button) == LOW) { outputs [button] ^= 1 ; digitalWrite (PIFACE_BASE + button, outputs [button]) ; printf ("Button %d pushed - output now: %s\n", button, (outputs [button] == 0) ? "Off" : "On") ; } while (digitalRead (PIFACE_BASE + button) == LOW) delay (1) ; } /* * start here ********************************************************************************* */ int main (void) { int pin, button ; printf ("Raspberry Pi wiringPi + PiFace test program\n") ; printf ("===========================================\n") ; printf ("\n") ; printf ( "This program reads the buttons and uses them to toggle the first 4\n" "outputs. Push a button once to turn an output on, and push it again to\n" "turn it off again.\n\n") ; // Always initialise wiringPi. Use wiringPiSys() if you don't need // (or want) to run as root wiringPiSetupSys () ; piFaceSetup (PIFACE_BASE) ; // Enable internal pull-ups & start with all off for (pin = 0 ; pin < 8 ; ++pin) { pullUpDnControl (PIFACE_BASE + pin, PUD_UP) ; digitalWrite (PIFACE_BASE + pin, 0) ; } // Loop, scanning the buttons for (;;) { for (button = 0 ; button < 4 ; ++button) scanButton (button) ; delay (5) ; } return 0 ; }