TIMESTAMP convert_time(uhd::time_spec_t ts, double rate)
{
TIMESTAMP ticks = ts.get_full_secs() * rate;
return ts.get_tick_count(rate) + ticks;
}
int UHD_SAFE_MAIN(int argc, char *argv[]){
uhd::set_thread_priority_safe();
//variables to be set by po
std::string args;
//setup the program options
po::options_description desc("Allowed options");
desc.add_options()
("help", "help message")
("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
;
po::variables_map vm;
po::store(po::parse_command_line(argc, argv, desc), vm);
po::notify(vm);
//print the help message
if (vm.count("help")){
std::cout << boost::format("UHD Test Timed Commands %s") % desc << std::endl;
return ~0;
}
//create a usrp device
std::cout << std::endl;
std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
//check if timed commands are supported
std::cout << std::endl;
std::cout << "Testing support for timed commands on this hardware... " << std::flush;
try{
usrp->set_command_time(uhd::time_spec_t(0.0));
usrp->clear_command_time();
}
catch (const std::exception &e){
std::cout << "fail" << std::endl;
std::cerr << "Got exception: " << e.what() << std::endl;
std::cerr << "Timed commands are not supported on this hardware." << std::endl;
return ~0;
}
std::cout << "pass" << std::endl;
//readback time really fast, time diff is small
std::cout << std::endl;
std::cout << "Perform fast readback of registers:" << std::endl;
uhd::time_spec_t total_time;
for (size_t i = 0; i < 100; i++){
const uhd::time_spec_t t0 = usrp->get_time_now();
const uhd::time_spec_t t1 = usrp->get_time_now();
total_time += (t1-t0);
}
std::cout << boost::format(
"Difference between paired reads: %f us"
) % (total_time.get_real_secs()/100*1e6) << std::endl;
//use a timed command to start a stream at a specific time
//this is not the right way start streaming at time x,
//but it should approximate it within control RTT/2
//setup streaming
std::cout << std::endl;
std::cout << "About to start streaming using timed command:" << std::endl;
//create a receive streamer
uhd::stream_args_t stream_args("fc32"); //complex floats
uhd::rx_streamer::sptr rx_stream = usrp->get_rx_stream(stream_args);
uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
stream_cmd.num_samps = 100;
stream_cmd.stream_now = true;
const uhd::time_spec_t stream_time = usrp->get_time_now() + uhd::time_spec_t(0.1);
usrp->set_command_time(stream_time);
rx_stream->issue_stream_cmd(stream_cmd);
usrp->clear_command_time();
//meta-data will be filled in by recv()
uhd::rx_metadata_t md;
//allocate buffer to receive with samples
std::vector<std::complex<float> > buff(stream_cmd.num_samps);
const size_t num_rx_samps = rx_stream->recv(&buff.front(), buff.size(), md, 1.0);
if (md.error_code != uhd::rx_metadata_t::ERROR_CODE_NONE){
throw std::runtime_error(str(boost::format(
"Unexpected error code 0x%x"
) % md.error_code));
}
std::cout << boost::format(
"Received packet: %u samples, %u full secs, %f frac secs"
) % num_rx_samps % md.time_spec.get_full_secs() % md.time_spec.get_frac_secs() << std::endl;
std::cout << boost::format(
"Stream time was: %u full secs, %f frac secs"
) % stream_time.get_full_secs() % stream_time.get_frac_secs() << std::endl;
std::cout << boost::format(
"Difference between stream time and first packet: %f us"
) % ((md.time_spec-stream_time).get_real_secs()/100*1e6) << std::endl;
//finished
std::cout << std::endl << "Done!" << std::endl << std::endl;
return EXIT_SUCCESS;
}