58 lines
1.2 KiB
C
58 lines
1.2 KiB
C
/*
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* Tutorial example #2
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* Part of Comedilib
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*
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* Copyright (c) 1999,2000 David A. Schleef <ds@schleef.org>
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*
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* This file may be freely modified, distributed, and combined with
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* other software, as long as proper attribution is given in the
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* source code.
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*/
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#include <stdio.h> /* for printf() */
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#include <comedilib.h>
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int subdev = 0; /* change this to your input subdevice */
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int chan = 0; /* change this to your channel */
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int range = 0; /* more on this later */
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int aref = AREF_GROUND; /* more on this later */
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const char filename[] = "/dev/comedi0";
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int main(int argc, char *argv[])
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{
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comedi_t *cf;
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lsampl_t data;
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int maxdata;
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double volts;
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comedi_range *cr;
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int retval;
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cf = comedi_open(filename);
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if(cf == NULL)
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{
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comedi_perror(filename);
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return 1;
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}
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maxdata = comedi_get_maxdata(cf, subdev, chan);
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if(maxdata == 0)
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{
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comedi_perror(filename);
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return 1;
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}
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cr = comedi_get_range(cf, subdev, chan, range);
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if(cr == NULL)
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{
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comedi_perror(filename);
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return 1;
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}
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retval = comedi_data_read(cf, subdev, chan, range, aref, &data);
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if(retval < 0)
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{
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comedi_perror(filename);
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return 1;
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}
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volts = comedi_to_phys(data, cr, maxdata);
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printf("%d %g\n", data, volts);
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return 0;
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}
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