/**
* Start the the ADC sampling, unless the external trigger command
* is set it will begin sampling as soon as the usbdux device has been
* initialized.
* The final three arguments are very important to get right
* as the recorder thread will use them to determine where to write it's samples and
* when it's reached end of the buffer. It doesn't care about the c_buffer class
* at all.
* @param arg_device name of the comedi device e.g., 'comedi0'
* @param arg_sample_rate the rate the usb_dux should sample with in hertz (max=3[Mhz]})
* @param arg_start_address the start address of the circle buffer sample should be loading into
* @param arg_end_address the end address of the cicle buffer.
* @param arg_buffer_size byte size of the buffer.
*/
int start_Sampling(char* arg_device, uint32_t arg_sample_rate,
char* arg_start_address, char* arg_end_address, int arg_buffer_size){
_channel_amount = 16;
_sample_rate = arg_sample_rate;
unsigned int chanlist[_channel_amount];
unsigned int convert_arg = 1e9 / _sample_rate;
int ret;
comedi_cmd *cmd = (comedi_cmd *) calloc(1, sizeof(comedi_cmd));
_device = comedi_open(arg_device);
int buffer = 1048576*40;
buffer = (buffer * 4096)/4096;
if(comedi_set_max_buffer_size(_device, 0, buffer) < 0 ){
printf("Failed to set max buffer size to %i bytes\n", buffer);
return -1;
} else printf("Maximum buffer size set to %i bytes\n", comedi_get_max_buffer_size(_device,0));
if(comedi_set_buffer_size(_device, 0, buffer) < 0){
printf("Failed to set buffer size to %iBytes\n", buffer);
return -1;
} else printf("Buffer size set to %iBytes\n", comedi_get_buffer_size(_device,0));
if(!_device){
errx(1, "unable to open device");
comedi_perror("/dev/comedi0");
return -1;
}
for(int i = 0; i < _channel_amount; i++)
chanlist[i] = i;
comedi_set_global_oor_behavior(COMEDI_OOR_NUMBER);
if((ret = comedi_get_cmd_generic_timed(_device, 0, cmd, _channel_amount,0)) < 0){
printf("comedi_get_cmd_generic_timed failed\n");
return ret;
}
cmd->chanlist = chanlist;
cmd->stop_src = TRIG_NONE;
cmd->stop_arg = 0;
cmd->convert_arg = convert_arg;
//setup the sampling to start from the trigger.
//cmd->start_src = TRIG_EXT
//cmd->start_arg = 1;
/* call test twice because different things are tested?
* if tests are successful run sampling command */
if((ret = comedi_command_test(_device, cmd)) != 0
|| (ret = comedi_command_test(_device, cmd)) != 0
|| (ret = comedi_command(_device, cmd)) < 0){
fprintf(stderr, "err: %d\n", ret);
return -1;
}
FILE* dux_fp;
if((dux_fp = fdopen(comedi_fileno(_device), "r")) <= 0)
comedi_perror("fdopen");
char* write_address = arg_start_address;
Utility::SNAP_SAMPLE = 0;
Utility::LAST_SAMPLE = 0;
uint64_t active_sample = 0;
uint32_t tmp_block = 0;
int samples_pr_block = 4096/sizeof(Type);
while((ret = fread(write_address, 1, 4096,dux_fp)) >= 0){
write_address += 4096;
tmp_block += 1;
active_sample += samples_pr_block;
Utility::LAST_SAMPLE += samples_pr_block;
if(tmp_block >= Utility::SNAPSHOT_BLOCK_SIZE){
//printf("signalling serial snapshotter\n");
tmp_block = 0;
Utility::SNAP_SAMPLE = active_sample;
Utility::SNAP_READY = true;
Utility::CV.notify_one();
}
if(write_address == arg_end_address){
write_address -= arg_buffer_size;
//printf("resetting to beginning of buffer\n");
}
if(_stop == true)
break;
}
if(ret < 0)
perror("read");
comedi_cancel(_device, 0);
return 0;
}
int _comedi_get_buffer_size(comedi_t *it, unsigned int subdev)
{
return comedi_set_buffer_size(it, subdev, 0);
}
