Get Started with UHD

// Receive samples from a USRP and write them to a binary file.
// Adapted from host/examples/rx_samples_to_file.cpp
#include <uhd/usrp/multi_usrp.hpp>
#include <uhd/types/tune_request.hpp>
#include <uhd/utils/safe_main.hpp>
#include <complex>
#include <fstream>
#include <iostream>
#include <vector>

int UHD_SAFE_MAIN(int argc, char* argv[])
{
    // --- Device parameters ---
    const std::string args   = "addr=192.168.10.2";
    const double      freq   = 2.45e9;   // Center frequency (Hz)
    const double      rate   = 1e6;      // Sample rate (sps)
    const double      gain   = 10.0;     // RX gain (dB)
    const size_t      n_samps = 1000000; // Samples to capture
    const std::string file   = "samples.dat";

    // --- Create device ---
    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
    std::cout << "Using Device: " << usrp->get_pp_string() << std::endl;

    // --- Configure radio ---
    usrp->set_rx_rate(rate);
    usrp->set_rx_freq(uhd::tune_request_t(freq));
    usrp->set_rx_gain(gain);

    std::cout << "Actual RX Rate: " << usrp->get_rx_rate() / 1e6
              << " Msps" << std::endl;

    // --- Create RX streamer (fc32 host / sc16 wire) ---
    uhd::stream_args_t stream_args("fc32", "sc16");
    stream_args.channels = {0};
    uhd::rx_streamer::sptr rx_stream = usrp->get_rx_stream(stream_args);

    // --- Issue stream command ---
    uhd::stream_cmd_t stream_cmd(
        uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
    stream_cmd.num_samps  = n_samps;
    stream_cmd.stream_now = true;
    rx_stream->issue_stream_cmd(stream_cmd);

    // --- Receive loop ---
    const size_t samps_per_buf = rx_stream->get_max_num_samps();
    std::vector<std::complex<float>> buf(samps_per_buf);
    uhd::rx_metadata_t md;
    std::ofstream outfile(file, std::ofstream::binary);

    size_t total = 0;
    while (total < n_samps) {
        size_t n = rx_stream->recv(&buf.front(), samps_per_buf, md, 3.0);
        if (md.error_code != uhd::rx_metadata_t::ERROR_CODE_NONE) {
            std::cerr << "Receiver error: " << md.strerror() << std::endl;
            break;
        }
        outfile.write(reinterpret_cast<const char*>(buf.data()),
                      n * sizeof(std::complex<float>));
        total += n;
    }

    outfile.close();
    std::cout << "Received " << total << " samples, saved to "
              << file << std::endl;
    return EXIT_SUCCESS;
}

# With pkg-config
g++ -std=c++14 rx_example.cpp $(pkg-config --cflags --libs uhd) -o rx_example

# Or with CMake — add to CMakeLists.txt:
# find_package(UHD REQUIRED)
# target_link_libraries(rx_example UHD::UHD)

./rx_example
# Or use the installed example binary:
rx_samples_to_file --args "addr=192.168.10.2" --freq 2.45e9 --rate 1e6 \
                   --duration 5 --file samples.dat