wiringPi_Blueberry/examples/Gertboard/voltmeter.c
2023-08-11 15:53:17 +08:00

74 lines
1.9 KiB
C

/*
* voltmeter.c:
* Demonstrate use of the Gertboard A to D converter to make
* a simple voltmeter.
*
* 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 <gertboard.h>
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 ;
}