comedilib/demo/mmap.c
Frank Mori Hess c1082cee65 Fixed comedi_get_cmd_generic_timed() by adding a chanlist_len
parameter.  Old version is still available in library, thanks to the
magic of the version_script.
2007-08-02 19:46:44 +00:00

170 lines
3.7 KiB
C

/*
* Example of using commands - asynchronous input
* Part of Comedilib
*
* Copyright (c) 1999,2000 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
* source code.
*/
/*
* An example for directly using Comedi commands. Comedi commands
* are used for asynchronous acquisition, with the timing controlled
* by on-board timers or external events.
*/
#include <stdio.h>
#include <comedilib.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <sys/mman.h>
#include <string.h>
#include "examples.h"
unsigned int chanlist[256];
void *map;
int prepare_cmd_lib(comedi_t *dev, int subdevice, int n_scan, int n_chan, unsigned period_nanosec, comedi_cmd *cmd);
int prepare_cmd(comedi_t *dev, int subdevice, int n_scan, int n_chan, unsigned period_nanosec, comedi_cmd *cmd);
int main(int argc, char *argv[])
{
comedi_t *dev;
comedi_cmd c,*cmd=&c;
int size;
int front, back;
int ret;
int i;
struct parsed_options options;
init_parsed_options(&options);
parse_options(&options, argc, argv);
dev = comedi_open(options.filename);
if(!dev){
comedi_perror(options.filename);
exit(1);
}
size = comedi_get_buffer_size(dev, options.subdevice);
fprintf(stderr,"buffer size is %d\n", size);
map = mmap(NULL,size,PROT_READ,MAP_SHARED, comedi_fileno(dev), 0);
fprintf(stderr, "map=%p\n", map);
if( map == MAP_FAILED ){
perror( "mmap" );
exit(1);
}
for(i = 0; i < options.n_chan; i++){
chanlist[i] = CR_PACK(options.channel + i, options.range, options.aref);
}
//prepare_cmd_lib(dev, options.subdevice, options.n_scan, options.n_chan, 1e9 / options.freq, cmd);
prepare_cmd(dev, options.subdevice, options.n_scan, options.n_chan, 1e9 / options.freq, cmd);
ret = comedi_command_test(dev, cmd);
ret = comedi_command_test(dev, cmd);
if(ret != 0){
fprintf(stderr,"command_test failed\n");
exit(1);
}
dump_cmd(stderr, cmd);
ret = comedi_command(dev, cmd);
if(ret < 0){
comedi_perror("comedi_command");
exit(1);
}
front = 0;
back = 0;
while(1){
front += comedi_get_buffer_contents(dev, options.subdevice);
if(options.verbose) fprintf(stderr, "front = %d, back = %d\n", front, back);
if(front < back) break;
if(front == back){
//comedi_poll(dev, options.subdevice);
usleep(10000);
continue;
}
for(i = back; i < front; i += sizeof(sampl_t)){
static int col = 0;
printf("%d ",*(sampl_t *)(map + (i % size)));
col++;
if(col == options.n_chan){
printf("\n");
col = 0;
}
}
ret = comedi_mark_buffer_read(dev, options.subdevice, front - back);
if(ret < 0){
comedi_perror("comedi_mark_buffer_read");
break;
}
back = front;
}
return 0;
}
int prepare_cmd_lib(comedi_t *dev, int subdevice, int n_scan, int n_chan, unsigned scan_period_nanosec, comedi_cmd *cmd)
{
int ret;
ret = comedi_get_cmd_generic_timed(dev, subdevice, cmd, n_chan, scan_period_nanosec);
if(ret<0){
comedi_perror("comedi_get_cmd_generic_timed\n");
return ret;
}
cmd->chanlist = chanlist;
cmd->chanlist_len = n_chan;
if(cmd->stop_src == TRIG_COUNT) cmd->stop_arg = n_scan;
return 0;
}
int prepare_cmd(comedi_t *dev, int subdevice, int n_scan, int n_chan, unsigned period_nanosec, comedi_cmd *cmd)
{
memset(cmd,0,sizeof(*cmd));
cmd->subdev = subdevice;
cmd->flags = 0;
cmd->start_src = TRIG_NOW;
cmd->start_arg = 0;
cmd->scan_begin_src = TRIG_TIMER;
cmd->scan_begin_arg = period_nanosec;
cmd->convert_src = TRIG_TIMER;
cmd->convert_arg = 1;
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;
return 0;
}