Dear all
I’m trying to get samples from two USRP2s connected via MIMO cable and
the Gigabit ethernet cable is connected with the PC with only one USRP2.
What I couldn’t figure out is only one of the USRP2s getting the samples
and the other is not. I am testing this by using one of the examples
from the uhd i.e. rx_multi_samples.cpp. The code is executed from the
terminal as
$ ./rx_multi_samples --args=“addr0=192.168.10.2, addr1=192.168.10.3”
–sync=mimo.
If anyone has any suggestion I really appreciate it.
#include <uhd/utils/thread_priority.hpp>
#include <uhd/utils/safe_main.hpp>
#include <uhd/usrp/multi_usrp.hpp>
#include <boost/program_options.hpp>
#include <boost/format.hpp>
#include <boost/thread.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/algorithm/string.hpp>
#include
#include
namespace po = boost::program_options;
using namespace std;
int UHD_SAFE_MAIN(int argc, char *argv[]){
uhd::set_thread_priority_safe();
//variables to be set by po
std::string args, sync, subdev, channel_list;
double seconds_in_future;
size_t total_num_samps;
double rate;
//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”)
(“secs”,
po::value(&seconds_in_future)->default_value(1.5), “number of
seconds in the future to receive”)
(“nsamps”,
po::value<size_t>(&total_num_samps)->default_value(10000), “total number
of samples to receive”)
(“rate”, po::value(&rate)->default_value(100e6/16),
“rate of incoming samples”)
(“sync”, po::valuestd::string(&sync)->default_value(“now”),
“synchronization method: now, pps, mimo”)
(“subdev”, po::valuestd::string(&subdev), “subdev spec
(homogeneous across motherboards)”)
(“dilv”, “specify to disable inner-loop verbose”)
(“channels”,
po::valuestd::string(&channel_list)->default_value(“0”), “which
channel(s) to use (specify “0”, “1”, “0,1”, etc)”)
;
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 RX Multi Samples %s") % desc <<
std::endl;
std::cout <<
" This is a demonstration of how to receive aligned data from
multiple channels.\n"
" This example can receive from multiple DSPs, multiple
motherboards, or both.\n"
" The MIMO cable or PPS can be used to synchronize the
configuration. See --sync\n"
“\n”
" Specify --subdev to select multiple channels per
motherboard.\n"
" Ex: --subdev=“0:A 0:B” to get 2 channels on a Basic
RX.\n"
“\n”
" Specify --args to select multiple motherboards in a
configuration.\n"
" Ex: --args=“addr0=192.168.10.2, addr1=192.168.10.3”\n"
<< std::endl;
return ~0;
}
bool verbose = vm.count("dilv") == 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);
//always select the subdevice first, the channel mapping affects the
other settings
if (vm.count(“subdev”)) usrp->set_rx_subdev_spec(subdev); //sets
across all mboards
if (vm.count(“subdev1”)) usrp->set_rx_subdev_spec(subdev1); //sets
across all mboards
std::cout << boost::format("Using Device: %s") %
usrp->get_pp_string() << std::endl;
//set the rx sample rate (sets across all channels)
std::cout << boost::format("Setting RX Rate: %f Msps...") %
(rate/1e6) << std::endl;
usrp->set_rx_rate(rate);
std::cout << boost::format(“Actual RX Rate: %f Msps…”) %
(usrp->get_rx_rate()/1e6) << std::endl << std::endl;
std::cout << boost::format("Setting device timestamp to 0...") <<
std::endl;
if (sync == “now”){
//This is not a true time lock, the devices will be off by a few
RTT.
//Rather, this is just to allow for demonstration of the code
below.
usrp->set_time_now(uhd::time_spec_t(0.0));
}
else if (sync == “pps”){
usrp->set_time_source(“external”);
usrp->set_time_unknown_pps(uhd::time_spec_t(0.0));
boost::this_thread::sleep(boost::posix_time::seconds(1)); //wait
for pps sync pulse
}
else if (sync == “mimo”){
UHD_ASSERT_THROW(usrp->get_num_mboards() == 2);
//make mboard 1 a slave over the MIMO Cable
usrp->set_clock_source("mimo", 1);
usrp->set_time_source("mimo", 1);
//set time on the master (mboard 0)
usrp->set_time_now(uhd::time_spec_t(0.0), 0);
//sleep a bit while the slave locks its time to the master
boost::this_thread::sleep(boost::posix_time::milliseconds(1000));
}
//detect which channels to use
std::vector<std::string> channel_strings;
std::vector<size_t> channel_nums;
boost::split(channel_strings, channel_list,
boost::is_any_of(""’,"));
for(size_t ch = 0; ch < channel_strings.size(); ch++){
size_t chan = boost::lexical_cast(channel_strings[ch]);
if(chan >= usrp->get_rx_num_channels()){
throw std::runtime_error(“Invalid channel(s) specified.”);
}
else
channel_nums.push_back(boost::lexical_cast(channel_strings[ch]));
}
//create a receive streamer
//linearly map channels (index0 = channel0, index1 = channel1, ...)
uhd::stream_args_t stream_args("fc32"); //complex floats
stream_args.channels = channel_nums;
uhd::rx_streamer::sptr rx_stream = usrp->get_rx_stream(stream_args);
//setup streaming
std::cout << std::endl;
std::cout << boost::format(
"Begin streaming %u samples, %f seconds in the future..."
) % total_num_samps % seconds_in_future << std::endl;
uhd::stream_cmd_t
stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
stream_cmd.num_samps = total_num_samps;
stream_cmd.stream_now = false;
stream_cmd.time_spec = uhd::time_spec_t(seconds_in_future);
rx_stream->issue_stream_cmd(stream_cmd); //tells all channels to
stream
//meta-data will be filled in by recv()
uhd::rx_metadata_t md;
//allocate buffers to receive with samples (one buffer per channel)
const size_t samps_per_buff = rx_stream->get_max_num_samps();
std::vector<std::vector<std::complex<float> > > buffs(
usrp->get_rx_num_channels(), std::vector<std::complex<float>
(samps_per_buff)
);
//create a vector of pointers to point to each of the channel
buffers
std::vector<std::complex *> buff_ptrs;
for (size_t i = 0; i < buffs.size(); i++)
buff_ptrs.push_back(&buffs[i].front());
//the first call to recv() will block this many seconds before
receiving
double timeout = seconds_in_future + 0.1; //timeout (delay before
receive + padding)
vector<std::complex >::iterator it1 = buffs[0].begin();
vector<std::complex >::iterator it2 = buffs[1].begin();
size_t num_acc_samps = 0; //number of accumulated samples
while(num_acc_samps < total_num_samps){
//receive a single packet
size_t num_rx_samps = rx_stream->recv(
buff_ptrs, samps_per_buff, md, timeout
);
//use a small timeout for subsequent packets
timeout = 0.1;
//handle the error code
if (md.error_code == uhd::rx_metadata_t::ERROR_CODE_TIMEOUT)
break;
if (md.error_code != uhd::rx_metadata_t::ERROR_CODE_NONE){
throw std::runtime_error(str(boost::format(
“Receiver error %s”
) % md.strerror()));
}
if(verbose) 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;
num_acc_samps += num_rx_samps;
for (size_t i = 0; i < 363; i++)
{
cout << "
buffs[1].front()<<<<<<<<<<<<<<<<<<<<<" << it2[i] << endl;
cout << “buffs[0].front()>>>>>>>>>>>>>>>>>>>>>” << it1[i] << endl;
}
}
if (num_acc_samps < total_num_samps) std::cerr << "Receive timeout
before all samples received…" << std::endl;
//finished
std::cout << std::endl << “Done!” << std::endl << std::endl;
return EXIT_SUCCESS;
}