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/*
* Copyright 2011 Free Software Foundation, Inc.
*
* GNU Radio is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* GNU Radio is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
/*
* Simple GNU Radio C++ example for using the Funcube Dongle.
*
* Construct a simple narrow band FM receiver using the gr-fcd
* block as source.
*
* This example uses "hw:1" as FCD source device and the default
* audio device for output.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
// Include header files for each block used in flowgraph
#include <gr_top_block.h>
#include <gr_firdes.h>
#include <gr_fir_filter_ccf.h>
#include <gr_quadrature_demod_cf.h>
#include <gr_audio_sink.h>
#include <fcd_source_c.h>
// other includes
#include <iostream>
#include <boost/program_options.hpp>
namespace po = boost::program_options;
int main(int argc, char **argv)
{
int rate = 48000; // Audio card sample rate
float pi = 3.141592654;
//variables to be set by po
std::string device;
int freq;
float gain;
//setup the program options
po::options_description desc("Command line options");
desc.add_options()
("help", "This help message")
("device", po::value<std::string>(&device)->default_value("hw:1"), "Audio input device")
("freq", po::value<int>(&freq)->default_value(145500), "RF frequency in kHz")
("gain", po::value<float>(&gain)->default_value(20.0), "LNA gain in dB")
;
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 << "Narrow band FM receiver example" << std::endl << desc << std::endl;
return ~0;
}
// Construct a top block that will contain flowgraph blocks.
gr_top_block_sptr tb = gr_make_top_block("fcd_nfm_rx");
// FCD source
fcd_source_c_sptr fcd = fcd_make_source_c(device);
fcd->set_freq_khz(freq);
fcd->set_lna_gain(gain);
// Low pass filter
std::vector<float> taps = gr_firdes::low_pass(1.0, 96000, 5000.0, 1000.0);
gr_fir_filter_ccf_sptr filter = gr_make_fir_filter_ccf (2, taps);
// FM demodulator
// gain = sample_rate / (2*pi*max_dev)
gr_quadrature_demod_cf_sptr demod = gr_make_quadrature_demod_cf (rate/(2.0*pi*5000.0));
// Audio sink
audio_sink::sptr sink = audio_make_sink(rate);
// Connect blocks
tb->connect(fcd, 0, filter, 0);
tb->connect(filter, 0, demod, 0);
tb->connect(demod, 0, sink, 0);
// Tell GNU Radio runtime to start flowgraph threads; the foreground thread
// will block until either flowgraph exits (this example doesn't) or the
// application receives SIGINT (e.g., user hits CTRL-C).
//
// Real applications may use tb->start() which returns, allowing the foreground
// thread to proceed, then later use tb->stop(), followed by tb->wait(), to cleanup
// GNU Radio before exiting.
tb->run();
// Exit normally.
return 0;
}
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