Thanks Marcus,
You are right I misunderstood the concept, I thought that they where
absolute seconds...
After correcting that plus a little other detail it seems to be working....
Thanks for your help.
>From Android Device
El mar., abr. 23, 2019 12:23, Marcus D. Leech <patchvonbr...@gmail.com>
escribió:
> On 04/23/2019 07:35 AM, Guillermo Gancio wrote:
> > Thanks Marcus for the answer and your time,
> >
> > This is the part of the code with all the configurations....the rest
> > is too messy to share I think..and its based in rx_samples_c.c
> > The UHD version is...
> > linux; GNU C++ version 4.8.4; Boost_105400;
> UHD_003.010.003.HEAD-0-gef157678
> >
> > Thanks!
> I would update to a newer UHD, but also I think you have a logic error
> in your code that causes the start time to be in the past--
> you sleep for 1.5 seconds after setting the USRP time to zero, which
> means that there's some possibility that when you ask for
> an absolute time of 2 on the stream command, that time has already
> passed.
>
>
> >
> > // Set up of the B2xx
> > board---------------------------------------------------------
> > // Create USRP
> > uhd_usrp_handle usrp;
> > fprintf(stderr, "Creating USRP with args \"%s\"...\n", device_args);
> > EXECUTE_OR_GOTO(free_option_strings,
> > uhd_usrp_make(&usrp, device_args)
> > )
> >
> > // Create RX streamer
> > uhd_rx_streamer_handle rx_streamer;
> > EXECUTE_OR_GOTO(free_usrp,
> > uhd_rx_streamer_make(&rx_streamer)
> > )
> >
> > // Create RX metadata
> > uhd_rx_metadata_handle md;
> > EXECUTE_OR_GOTO(free_rx_streamer,
> > uhd_rx_metadata_make(&md)
> > )
> >
> > // Create other necessary structs
> > uhd_tune_request_t tune_request = {
> > .target_freq = freq,
> > .rf_freq_policy = UHD_TUNE_REQUEST_POLICY_AUTO,
> > .dsp_freq_policy = UHD_TUNE_REQUEST_POLICY_AUTO,
> > };
> > uhd_tune_result_t tune_result;
> > uhd_stream_args_t stream_args = {
> > .cpu_format = "sc16", //sc16
> > .otw_format = "sc8", //sc8
> > .args = "",
> > .channel_list = &channel,
> > .n_channels = 0
> > };
> > // Set rate
> > fprintf(stderr, "Setting RX Rate: %f...\n", rate);
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_set_rx_rate(usrp, rate, channel)
> > )
> >
> > // See what rate actually is
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_get_rx_rate(usrp, channel, &rate)
> > )
> > fprintf(stderr, "Actual RX Rate: %f...\n", rate);
> >
> > // Set gain
> > fprintf(stderr, "Setting RX Gain: %f dB...\n", gain);
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_set_rx_gain(usrp, gain, channel, "")
> > )
> >
> > // See what gain actually is
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_get_rx_gain(usrp, channel, "", &gain)
> > )
> > fprintf(stderr, "Actual RX Gain: %f...\n", gain);
> >
> >
> > // Set frequency
> > fprintf(stderr, "Setting RX frequency: %f MHz...\n", freq/1e6);
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_set_rx_freq(usrp, &tune_request, channel, &tune_result)
> > )
> >
> > // See what frequency actually is
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_get_rx_freq(usrp, channel, &freq)
> > )
> > int64_t aux_secs=0,aux_secs_loop=0;
> > double aux_frac_secs=0.0;
> > uhd_rx_metadata_error_code_t error_code;
> > if(use_PPS)
> > {
> > printf("Using PPS\n");
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_set_time_source(usrp, "external",channel)
> > )
> > sleep(0.25);
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_set_clock_source(usrp, "internal",channel)
> > )
> > sleep(1.5);
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_get_time_last_pps(usrp, channel,
> > &aux_secs,&aux_frac_secs)
> > )
> > printf("Get Last PPS.....%d -
> > %f\n",(int)aux_secs,aux_frac_secs);
> > do{
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_get_time_last_pps(usrp, channel,
> > &aux_secs_loop,&aux_frac_secs)
> > )
> > sleep(0.25);
> > }while(aux_secs==aux_secs_loop);
> > sleep(1.5);
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_set_time_next_pps(usrp,0,0.0,channel)
> > )
> > sleep(1.5);
> > }
> > EXECUTE_OR_GOTO(free_rx_metadata,
> > uhd_usrp_get_time_now(usrp, channel,
> > &aux_secs_loop,&aux_frac_secs)
> > )
> > printf("Get Time NOW.....%d -
> > %f\n",(int)aux_secs_loop,aux_frac_secs);
> > // Set up buffer
> > samps_per_buff_2=samps_per_buff;
> > EXECUTE_OR_GOTO(free_rx_streamer,
> > uhd_rx_streamer_max_num_samps(rx_streamer, &samps_per_buff_2)
> > )
> >
> > uhd_stream_cmd_t stream_cmd = {
> > .stream_mode = UHD_STREAM_MODE_START_CONTINUOUS,
> > .num_samps = 0,
> > .stream_now = false,
> > .time_spec_full_secs = 2
> > };
> >
> > EXECUTE_OR_GOTO(free_rx_streamer,
> > uhd_usrp_get_rx_stream(usrp, &stream_args, rx_streamer)
> > )
> >
> > EXECUTE_OR_GOTO(free_buffer,
> > uhd_rx_streamer_issue_stream_cmd(rx_streamer, &stream_cmd)
> > )
> > // Ettus B2xx Read loop
> > for(loop_samps=0;loop_samps<tot_samps;loop_samps++)
> > {
> > num_rx_samps = 0;
> > EXECUTE_OR_GOTO(close_file,
> > uhd_rx_streamer_recv(rx_streamer, buffs_ptr,
> > samps_per_buff, &md, 3.0, false, &num_rx_samps) //Actual reading.
> > )
> >
> > EXECUTE_OR_GOTO(close_file,
> > uhd_rx_metadata_error_code(md, &error_code)
> > )
> > if(error_code != UHD_RX_METADATA_ERROR_CODE_NONE){ // If there
> > is an error in the reading it will breake the loop and jump to close
> > the file.
> > fprintf(stderr, "Error code 0x%x was returned during
> > streaming. Aborting.\n", return_code);
> > goto close_file;
> > }
> > num_rx_samps2=num_rx_samps;
> >
> > if(fork_start==1){ //Wait for child process to finish, only
> > after first run..
> > sem_wait(fft_done);}
> > memcpy(glob_var,buff,(samps_per_buff * 2 * sizeof(d_type)));
> > sem_post(fft_start); // realse the child process for the FFT
> > and kept reading.
> > fork_start=1;
> > if (verbose) {
> > time_t full_secs;
> > double frac_secs;
> > uhd_rx_metadata_time_spec(md, &full_secs, &frac_secs);
> > fprintf(stderr, "Received packet: %zu samps request
> > %zu samples recieved, %d full secs, %f frac secs\n",
> > samps_per_buff,
> > num_rx_samps,
> > (int)full_secs,
> > frac_secs);
> > }
> > if(*fft_go==5)
> > goto close_file;
> > num_acc_samps += num_rx_samps;
> > }
> >
> >
> >
> >
> > El lun., 22 abr. 2019 a las 23:16, Marcus D. Leech via USRP-users
> > (<usrp-users@lists.ettus.com>) escribió:
> >> On 04/22/2019 09:36 PM, Guillermo Gancio via USRP-users wrote:
> >>> Hi all,
> >>>
> >>> I have a question trying to sync the start of data burst with a PPS
> signal.
> >>> With the options....
> >>> .stream_mode = UHD_STREAM_MODE_START_CONTINUOUS,
> >>> .num_samps = 0,
> >>> .stream_now = true
> >>>
> >>> the code works ok, but when I change to....
> >>> .stream_now = false,
> >>> .time_spec_full_secs = 2
> >>> The code gives...
> >>> UHD Error:
> >>> The receive packet handler caught a value exception.
> >>> ValueError: bad vrt header or packet fragment
> >>> Error code 0x0 was returned during streaming. Aborting.
> >>>
> >>> Before this I set the time_source to external and set the next PPS to
> 0 with...
> >> You might need to share more of your code, and also, what version of UHD
> >> are you using?
> >>
> >>
> >>> EXECUTE_OR_GOTO(free_rx_metadata,uhd_usrp_get_time_last_pps(usrp,
> >>> channel, &aux_secs,&aux_frac_secs) )
> >>> do{
> >>> sleep(0.25);
> >>> EXECUTE_OR_GOTO(free_rx_metadata,
> >>> uhd_usrp_get_time_last_pps(usrp, channel,
> >>> &aux_secs_loop,&aux_frac_secs) )
> >>> }while(aux_secs==aux_secs_loop);
> >>> sleep(0.25);
> >>> EXECUTE_OR_GOTO(free_rx_metadata,
> >>> uhd_usrp_set_time_next_pps(usrp, 0, 0.0,channel))
> >>>
> >>>
> >>> Any help will be very appreciated!
> >>>
> >>> Thanks!
> >>>
> >>> _______________________________________________
> >>> USRP-users mailing list
> >>> USRP-users@lists.ettus.com
> >>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
> >>
> >> _______________________________________________
> >> USRP-users mailing list
> >> USRP-users@lists.ettus.com
> >> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
> >
> >
>
>
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