71 lines
1.5 KiB
C
71 lines
1.5 KiB
C
/*
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This demo opens /dev/comedi0 and looks for an analog input
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subdevice. If it finds one, it measures one sample on each
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channel for each input range. The value NaN indicates that
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the measurement was out of range.
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*/
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#include <stdio.h>
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#include <comedilib.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <sys/ioctl.h>
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#include <errno.h>
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#include <getopt.h>
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#include <ctype.h>
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extern int verbose_flag;
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extern int subdevice;
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extern int range;
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extern int channel;
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extern int aref;
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extern char *filename;
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comedi_t *device;
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int main(int argc, char *argv[])
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{
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int n_subdevs;
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int n_chans,chan;
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int n_ranges;
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int range;
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int rangetype;
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int maxdata;
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lsampl_t data;
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double voltage;
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parse_options(argc,argv);
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device=comedi_open(filename);
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if(!device){
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comedi_perror(filename);
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exit(0);
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}
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subdevice=comedi_find_subdevice_by_type(device,COMEDI_SUBD_AI,0);
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if(subdevice<0){
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printf("no analog input subdevice found\n");
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exit(0);
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}
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n_chans=comedi_get_n_channels(device,subdevice);
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for(chan=0;chan<n_chans;chan++){
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printf("%d: ",chan);
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//n_ranges=comedi_get_n_ranges(device,subdevice,chan);
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rangetype=comedi_get_rangetype(device,subdevice,chan);
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n_ranges=RANGE_LENGTH(rangetype);
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maxdata=comedi_get_maxdata(device,subdevice,chan);
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for(range=0;range<n_ranges;range++){
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comedi_data_read(device,subdevice,chan,range,aref,&data);
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voltage=comedi_to_phys(data,comedi_get_range(device,subdevice,chan,range),maxdata);
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printf("%g ",voltage);
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}
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printf("\n");
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}
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exit(0);
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}
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