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Major fixes and added inline documentation. It's actually somewhat

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decent now.
This commit is contained in:
David Schleef 2001-07-14 00:50:15 +00:00
parent 494d76f823
commit 68e8bf7b0d
1 changed files with 188 additions and 144 deletions
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332
demo/cmd.c
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@ -2,7 +2,7 @@
* Example of using commands - asynchronous input
* Part of Comedilib
*
* Copyright (c) 1999,2000 David A. Schleef <ds@schleef.org>
* Copyright (c) 1999,2000,2001 David A. Schleef <ds@schleef.org>
*
* This file may be freely modified, distributed, and combined with
* other software, as long as proper attribution is given in the
@ -19,119 +19,135 @@
#include <comedilib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/time.h>
#include <errno.h>
#include <getopt.h>
#include <ctype.h>
#include <string.h>
#include "examples.h"
#define N_SCANS 10
#define N_CHANS 16
int n_chan = 4;
double freq = 1000;
#define BUFSZ 10000
char buf[BUFSZ];
#define N_CHANS 256
unsigned int chanlist[N_CHANS];
void prepare_cmd_1(comedi_t *dev,comedi_cmd *cmd);
void prepare_cmd_2(comedi_t *dev,comedi_cmd *cmd);
int prepare_cmd_lib(comedi_t *dev,int subdevice,comedi_cmd *cmd);
int prepare_cmd(comedi_t *dev,int subdevice,comedi_cmd *cmd);
void do_cmd(comedi_t *dev,comedi_cmd *cmd);
void dump_cmd(comedi_cmd *cmd);
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 cmd;
comedi_cmd c,*cmd=&c;
int ret;
int total=0;
int i;
struct timeval start,end;
parse_options(argc,argv);
/* The following global variables used in this demo are
* defined in main.c, and can be modified by command line
* options. When modifying this demo, you may want to
* change them here. */
//filename = "/dev/comedi0";
//subdevice = 0;
//channel = 0;
//range = 0;
//aref = AREF_GROUND;
//n_chan = 4;
//n_scan = 1000;
//freq = 1000.0;
/* open the device */
dev = comedi_open(filename);
if(!dev){
perror(filename);
comedi_perror(filename);
exit(1);
}
fcntl(comedi_fileno(dev),F_SETFL,O_NONBLOCK);
prepare_cmd_1(dev,&cmd);
do_cmd(dev,&cmd);
return 0;
}
void do_cmd(comedi_t *dev,comedi_cmd *cmd)
{
unsigned int *chanlist;
int n_chans;
int total=0;
int ret;
int go;
chanlist = cmd->chanlist;
n_chans = cmd->chanlist_len;
ret=comedi_command_test(dev,cmd);
printf("test ret=%d\n",ret);
if(ret<0){
printf("errno=%d\n",errno);
comedi_perror("comedi_command_test");
return;
/* Set up channel list */
for(i=0;i<n_chan;i++){
chanlist[i]=CR_PACK(channel+i,range,aref);
}
dump_cmd(cmd);
/* 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,subdevice,cmd);
prepare_cmd(dev,subdevice,cmd);
fprintf(stderr,"command before testing:\n");
dump_cmd(stderr,cmd);
#if 0
/* restoring the chanlist stuff in this way is only required
* for comedi versions before 0.7.56
*/
cmd->chanlist = chanlist;
cmd->chanlist_len = n_chans;
#endif
ret=comedi_command_test(dev,cmd);
printf("test ret=%d\n",ret);
/* 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){
printf("errno=%d\n",errno);
comedi_perror("comedi_command_test");
return;
if(errno==EIO){
fprintf(stderr,"Ummm... this subdevice doesn't support commands\n");
}
exit(1);
}
fprintf(stderr,"first test returned %d (%s)\n",ret,
cmdtest_messages[ret]);
dump_cmd(stderr,cmd);
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){
dump_cmd(stderr,cmd);
fprintf(stderr,"Error preparing command\n");
exit(1);
}
dump_cmd(cmd);
/* start the command */
ret=comedi_command(dev,cmd);
printf("ret=%d\n",ret);
if(ret<0){
printf("errno=%d\n",errno);
comedi_perror("comedi_command");
return;
exit(1);
}
go=1;
while(go){
/* this is only for informational purposes */
gettimeofday(&start,NULL);
fprintf(stderr,"start time: %ld.%06ld\n",start.tv_sec,start.tv_usec);
while(1){
ret=read(comedi_fileno(dev),buf,BUFSZ);
if(ret<0){
if(errno==EAGAIN){
usleep(10000);
}else{
go = 0;
perror("read");
}
/* some error occurred */
perror("read");
break;
}else if(ret==0){
go = 0;
/* reached stop condition */
break;
}else{
static int col = 0;
int i;
total+=ret;
//printf("read %d %d\n",ret,total);
#if 1
if(verbose)fprintf(stderr,"read %d %d\n",ret,total);
for(i=0;i<ret/2;i++){
printf("%d ",((sampl_t *)buf)[i]);
col++;
@ -140,18 +156,53 @@ void do_cmd(comedi_t *dev,comedi_cmd *cmd)
col=0;
}
}
#endif
}
}
/* this is only for informational purposes */
gettimeofday(&end,NULL);
fprintf(stderr,"end time: %ld.%06ld\n",end.tv_sec,end.tv_usec);
end.tv_sec-=start.tv_sec;
if(end.tv_usec<start.tv_usec){
end.tv_sec--;
end.tv_usec+=1000000;
}
end.tv_usec-=start.tv_usec;
fprintf(stderr,"time: %ld.%06ld\n",end.tv_sec,end.tv_usec);
return 0;
}
/*
* This part of the demo measures channels 1, 2, 3, 4 at a rate of
* 10 khz, with the inter-sample time at 10 us (100 khz). The number
* of scans measured is 10. This is analogous to the old mode2
* acquisition.
* 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,comedi_cmd *cmd)
{
int ret;
/* 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);
if(ret<0)return ret;
/* Modify parts of the command */
cmd->chanlist = chanlist;
cmd->chanlist_len = n_chan;
cmd->scan_end_arg = n_chan;
if(cmd->stop_src==TRIG_COUNT)cmd->stop_arg = n_scan;
return 0;
}
/*
* Set up a command by hand. This will not work on some devices.
* There is no single command that will work on all devices.
*/
void prepare_cmd_1(comedi_t *dev,comedi_cmd *cmd)
int prepare_cmd(comedi_t *dev,int subdevice,comedi_cmd *cmd)
{
memset(cmd,0,sizeof(cmd));
@ -159,36 +210,66 @@ void prepare_cmd_1(comedi_t *dev,comedi_cmd *cmd)
cmd->subdev = subdevice;
/* flags */
cmd->flags = TRIG_WAKE_EOS;
//cmd.flags = 0;
cmd->flags = 0;
/* Wake up at the end of every scan */
//cmd->flags |= TRIG_WAKE_EOS;
/* Use a real-time interrupt, if available */
//cmd->flags |= TRIG_RT;
/* each event requires a trigger, which is specified
by a source and an argument. For example, to specify
an external digital line 3 as a source, you would use
src=TRIG_EXT and arg=3. */
/* In this case, we specify using TRIG_NOW to start
* acquisition immediately when the command is issued.
* The argument of TRIG_NOW is "number of nsec after
* NOW", but no driver supports it yet. Also, no driver
* currently supports using a start_src other than
* TRIG_NOW. */
cmd->start_src = TRIG_NOW;
cmd->start_arg = 0;
/* The start of acquisition is controlled by start_src.
* TRIG_NOW: The start_src event occurs start_arg nanoseconds
* after comedi_command() is called. Currently,
* only start_arg=0 is supported.
* TRIG_FOLLOW: (For an output device.) The start_src event occurs
* when data is written to the buffer.
* TRIG_EXT: start event occurs when an external trigger
* signal occurs, e.g., a rising edge of a digital
* line. start_arg chooses the particular digital
* line.
* TRIG_INT: start event occurs on a Comedi internal signal,
* which is typically caused by an INSN_TRIG
* instruction.
*/
cmd->start_src = TRIG_NOW;
cmd->start_arg = 0;
/* The timing of the beginning of each scan is controlled
* by scan_begin. TRIG_TIMER specifies that scan_start
* events occur periodically at a rate of scan_begin_arg
* nanoseconds between scans. */
/* The timing of the beginning of each scan is controlled by
* scan_begin.
* TRIG_TIMER: scan_begin events occur periodically.
* The time between scan_begin events is
* convert_arg nanoseconds.
* TRIG_EXT: scan_begin events occur when an external trigger
* signal occurs, e.g., a rising edge of a digital
* line. scan_begin_arg chooses the particular digital
* line.
* TRIG_FOLLOW: scan_begin events occur immediately after a scan_end
* event occurs.
* The scan_begin_arg that we use here may not be supported exactly
* by the device, but it will be adjusted to the nearest supported
* value by comedi_command_test(). */
cmd->scan_begin_src = TRIG_TIMER;
cmd->scan_begin_arg = 10000000;
cmd->scan_begin_arg = 1e9/freq; /* in ns */
/* The timing between each sample in a scan is controlled
* by convert. Like above, TRIG_TIMER specifies that
* convert events occur periodically at a rate of convert_arg
* nanoseconds between scans. */
/* The timing between each sample in a scan is controlled by convert.
* TRIG_TIMER: Conversion events occur periodically.
* The time between convert events is
* convert_arg nanoseconds.
* TRIG_EXT: Conversion events occur when an external trigger
* signal occurs, e.g., a rising edge of a digital
* line. convert_arg chooses the particular digital
* line.
* TRIG_NOW: All conversion events in a scan occur simultaneously.
* Even though it is invalid, we specify 1 ns here. It will be
* adjusted later to a valid value by comedi_command_test() */
cmd->convert_src = TRIG_TIMER;
cmd->convert_arg = 10000; /* in ns */
cmd->convert_arg = 1; /* in ns */
/* The end of each scan is almost always specified using
* TRIG_COUNT, with the argument being the same as the
@ -199,13 +280,13 @@ void prepare_cmd_1(comedi_t *dev,comedi_cmd *cmd)
cmd->scan_end_arg = n_chan; /* number of channels */
/* The end of acquisition is controlled by stop_src and
* stop_arg. The src will typically be TRIG_COUNT or
* TRIG_NONE. Specifying TRIG_COUNT will stop acquisition
* after stop_arg number of scans, or TRIG_NONE will
* cause acquisition to continue until stopped using
* comedi_cancel(). */
* stop_arg.
* TRIG_COUNT: stop acquisition after stop_arg scans.
* TRIG_NONE: continuous acquisition, until stopped using
* comedi_cancel()
* */
cmd->stop_src = TRIG_COUNT;
cmd->stop_arg = 10000;
cmd->stop_arg = n_scan;
/* the channel list determined which channels are sampled.
In general, chanlist_len is the same as scan_end_arg. Most
@ -213,44 +294,7 @@ void prepare_cmd_1(comedi_t *dev,comedi_cmd *cmd)
cmd->chanlist = chanlist;
cmd->chanlist_len = n_chan;
chanlist[0]=CR_PACK(channel+0,range,aref);
chanlist[1]=CR_PACK(channel+1,range,aref);
chanlist[2]=CR_PACK(channel+2,range,aref);
chanlist[3]=CR_PACK(channel+3,range,aref);
return 0;
}
/*
*/
void prepare_cmd_2(comedi_t *dev,comedi_cmd *cmd)
{
memset(cmd,0,sizeof(cmd));
cmd->subdev = subdevice;
//cmd->flags = TRIG_RT|TRIG_WAKE_EOS;
cmd->flags = 0;
cmd->start_src = TRIG_NOW;
cmd->start_arg = 0;
cmd->scan_begin_src = TRIG_TIMER;
cmd->scan_begin_arg = 1;
cmd->convert_src = TRIG_TIMER;
cmd->convert_arg = 1000000;
cmd->scan_end_src = TRIG_COUNT;
cmd->scan_end_arg = n_chan;
cmd->stop_src = TRIG_NONE;
cmd->stop_arg = 0;
cmd->chanlist = chanlist;
cmd->chanlist_len = n_chan;
chanlist[0]=CR_PACK(channel+0,range,aref);
chanlist[1]=CR_PACK(channel+1,range,aref);
chanlist[2]=CR_PACK(channel+2,range,aref);
chanlist[3]=CR_PACK(channel+3,range,aref);
}