79 lines
2.1 KiB
C
79 lines
2.1 KiB
C
/*
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* temperature.c:
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* Demonstrate use of the Gertboard A to D converter to make
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* a simple thermometer using the LM35.
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*
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* Copyright (c) 2012-2013 Gordon Henderson. <projects@drogon.net>
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***********************************************************************
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* This file is part of wiringPi:
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* https://projects.drogon.net/raspberry-pi/wiringpi/
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*
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* wiringPi is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* wiringPi is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with wiringPi. If not, see <http://www.gnu.org/licenses/>.
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***********************************************************************
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*/
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#include <stdio.h>
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#include <wiringPi.h>
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#include <gertboard.h>
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int main ()
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{
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int x1, x2 ;
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double v1, v2 ;
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printf ("\n") ;
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printf ("Gertboard demo: Simple Thermemeter\n") ;
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printf ("==================================\n") ;
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// Always initialise wiringPi. Use wiringPiSys() if you don't need
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// (or want) to run as root
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wiringPiSetupSys () ;
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// Initialise the Gertboard analog hardware at pin 100
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gertboardAnalogSetup (100) ;
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printf ("\n") ;
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printf ("| Channel 0 | Channel 1 | Temperature 1 | Temperature 2 |\n") ;
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for (;;)
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{
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// Read the 2 channels:
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x1 = analogRead (100) ;
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x2 = analogRead (101) ;
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// Convert to a voltage:
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v1 = (double)x1 / 1023.0 * 3.3 ;
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v2 = (double)x2 / 1023.0 * 3.3 ;
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// Print
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printf ("| %6.3f | %6.3f |", v1, v2) ;
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// Print Temperature of both channels by converting the LM35 reading
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// to a temperature. Fortunately these are easy: 0.01 volts per C.
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printf (" %4.1f | %4.1f |\r", v1 * 100.0, v2 * 100.0) ;
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fflush (stdout) ;
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}
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return 0 ;
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}
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