comedilib/demo/tut3.c

221 lines
5.6 KiB
C

/*
* Example of using commands - asynchronous input
* Part of Comedilib
*
* Copyright (c) 1999,2000,2001 David A. Schleef <ds@schleef.org>
* 2008 Bernd Porr <berndporr@f2s.com>
*
* This file may be freely modified, distributed, and combined with
* other software, as long as proper attribution is given in the
* source code.
*/
/*
* The program is used to test the usbdux sigma board
*/
#include <stdio.h>
#include <comedilib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/time.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
extern comedi_t *device;
struct parsed_options
{
char *filename;
double value;
int subdevice;
int channel;
int aref;
int range;
int verbose;
int n_chan;
int n_scan;
double freq;
};
#define BUFSZ 10000
char buf[BUFSZ];
#define N_CHANS 256
static unsigned int chanlist[N_CHANS];
static comedi_range * range_info[N_CHANS];
static lsampl_t maxdata[N_CHANS];
int prepare_cmd_lib(comedi_t *dev, int subdevice, int n_scan, int n_chan, unsigned period_nanosec, comedi_cmd *cmd);
void do_cmd(comedi_t *dev,comedi_cmd *cmd);
void print_datum(lsampl_t raw, int channel_index);
char *cmdtest_messages[]={
"success",
"invalid source",
"source conflict",
"invalid argument",
"argument conflict",
"invalid chanlist",
};
int main(int argc, char *argv[])
{
comedi_t *dev;
comedi_cmd c,*cmd=&c;
int ret;
int total=0;
int i;
int subdev_flags;
lsampl_t raw;
struct parsed_options options;
memset(&options, 0, sizeof(options));
/* The following variables used in this demo
* can be modified by command line
* options. When modifying this demo, you may want to
* change them here. */
options.filename = "/dev/comedi0";
options.subdevice = 0;
options.channel = 0;
options.range = 0;
options.aref = AREF_GROUND;
options.n_chan = 2;
options.n_scan = 10000;
options.freq = 1000.0;
/* open the device */
dev = comedi_open(options.filename);
if(!dev){
comedi_perror(options.filename);
exit(1);
}
// Print numbers for clipped inputs
comedi_set_global_oor_behavior(COMEDI_OOR_NUMBER);
/* Set up channel list */
for(i = 0; i < options.n_chan; i++){
chanlist[i] = CR_PACK(options.channel + i, options.range, options.aref);
range_info[i] = comedi_get_range(dev, options.subdevice, options.channel, options.range);
maxdata[i] = comedi_get_maxdata(dev, options.subdevice, options.channel);
}
/* prepare_cmd_lib() uses a Comedilib routine to find a
* good command for the device. prepare_cmd() explicitly
* creates a command, which may not work for your device. */
prepare_cmd_lib(dev, options.subdevice, options.n_scan, options.n_chan, 1e9 / options.freq, cmd);
/* comedi_command_test() tests a command to see if the
* trigger sources and arguments are valid for the subdevice.
* If a trigger source is invalid, it will be logically ANDed
* with valid values (trigger sources are actually bitmasks),
* which may or may not result in a valid trigger source.
* If an argument is invalid, it will be adjusted to the
* nearest valid value. In this way, for many commands, you
* can test it multiple times until it passes. Typically,
* if you can't get a valid command in two tests, the original
* command wasn't specified very well. */
ret = comedi_command_test(dev, cmd);
if(ret < 0){
comedi_perror("comedi_command_test");
if(errno == EIO){
fprintf(stderr,"Ummm... this subdevice doesn't support commands\n");
}
exit(1);
}
ret = comedi_command_test(dev, cmd);
if(ret < 0){
comedi_perror("comedi_command_test");
exit(1);
}
fprintf(stderr,"second test returned %d (%s)\n", ret,
cmdtest_messages[ret]);
if(ret!=0){
fprintf(stderr, "Error preparing command\n");
exit(1);
}
/* start the command */
ret = comedi_command(dev, cmd);
if(ret < 0){
comedi_perror("comedi_command");
exit(1);
}
subdev_flags = comedi_get_subdevice_flags(dev, options.subdevice);
while(1){
ret = read(comedi_fileno(dev),buf,BUFSZ);
if(ret < 0){
/* some error occurred */
perror("read");
break;
}else if(ret == 0){
/* reached stop condition */
break;
}else{
static int col = 0;
int bytes_per_sample;
total += ret;
if(options.verbose)fprintf(stderr, "read %d %d\n", ret, total);
if(subdev_flags & SDF_LSAMPL)
bytes_per_sample = sizeof(lsampl_t);
else
bytes_per_sample = sizeof(sampl_t);
for(i = 0; i < ret / bytes_per_sample; i++){
if(subdev_flags & SDF_LSAMPL) {
raw = ((lsampl_t *)buf)[i];
} else {
raw = ((sampl_t *)buf)[i];
}
print_datum(raw, col);
col++;
if(col == options.n_chan){
printf("\n");
col=0;
}
}
}
}
return 0;
}
/*
* This prepares a command in a pretty generic way. We ask the
* library to create a stock command that supports periodic
* sampling of data, then modify the parts we want. */
int prepare_cmd_lib(comedi_t *dev, int subdevice, int n_scan, int n_chan, unsigned scan_period_nanosec, comedi_cmd *cmd)
{
int ret;
memset(cmd,0,sizeof(*cmd));
/* This comedilib function will get us a generic timed
* command for a particular board. If it returns -1,
* that's bad. */
ret = comedi_get_cmd_generic_timed(dev, subdevice, cmd, n_chan, scan_period_nanosec);
if(ret<0){
printf("comedi_get_cmd_generic_timed failed\n");
return ret;
}
/* Modify parts of the command */
cmd->chanlist = chanlist;
cmd->chanlist_len = n_chan;
if(cmd->stop_src == TRIG_COUNT) cmd->stop_arg = n_scan;
return 0;
}
void print_datum(lsampl_t raw, int channel_index) {
double physical_value;
physical_value = comedi_to_phys(raw, range_info[channel_index], maxdata[channel_index]);
printf("%#8.6g ",physical_value);
}