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Diffstat (limited to 'gr-pager/apps/usrp_flex.py')
| -rwxr-xr-x | gr-pager/apps/usrp_flex.py | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/gr-pager/apps/usrp_flex.py b/gr-pager/apps/usrp_flex.py new file mode 100755 index 000000000..f8d9d25b1 --- /dev/null +++ b/gr-pager/apps/usrp_flex.py @@ -0,0 +1,172 @@ +#!/usr/bin/env python +# +# Copyright 2006,2007,2009 Free Software Foundation, Inc. +# +# This file is part of GNU Radio +# +# 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. +# + +from gnuradio import gr, gru, usrp, optfir, eng_notation, pager +from gnuradio.eng_option import eng_option +from optparse import OptionParser +import time, os, sys + +""" +This example application demonstrates receiving and demodulating the +FLEX pager protocol. + +The following are required command line parameters: + +-f FREQ USRP receive frequency + +The following are optional command line parameters: + +-R SUBDEV Daughter board specification, defaults to first found +-F FILE Read samples from a file instead of USRP. +-c FREQ Calibration offset. Gets added to receive frequency. + Defaults to 0.0 Hz. +-g GAIN Daughterboard gain setting. Defaults to mid-range. +-l Log flow graph to files (LOTS of data) +-v Verbose output + +Once the program is running, ctrl-break (Ctrl-C) stops operation. +""" + +class app_top_block(gr.top_block): + def __init__(self, options, queue): + gr.top_block.__init__(self, "usrp_flex") + self.options = options + self.offset = 0.0 + self.adj_time = time.time() + self.verbose = options.verbose + + if options.from_file is None: + # Set up USRP source with specified RX daughterboard + self.src = usrp.source_c() + if options.rx_subdev_spec == None: + options.rx_subdev_spec = usrp.pick_rx_subdevice(self.src) + self.subdev = usrp.selected_subdev(self.src, options.rx_subdev_spec) + self.src.set_mux(usrp.determine_rx_mux_value(self.src, options.rx_subdev_spec)) + + # Grab 250 KHz of spectrum (sample rate becomes 250 ksps complex) + self.src.set_decim_rate(256) + + # If no gain specified, set to midrange + if options.gain is None: + g = self.subdev.gain_range() + options.gain = (g[0]+g[1])/2.0 + self.subdev.set_gain(options.gain) + + # Tune daughterboard + actual_frequency = options.frequency+options.calibration + tune_result = usrp.tune(self.src, 0, self.subdev, actual_frequency) + if not tune_result: + sys.stderr.write("Failed to set center frequency to "+`actual_frequency`+"\n") + sys.exit(1) + + if options.verbose: + print "Using RX daughterboard", self.subdev.side_and_name() + print "USRP gain is", options.gain + print "USRP tuned to", actual_frequency + + else: + # Use supplied file as source of samples + self.src = gr.file_source(gr.sizeof_gr_complex, options.from_file) + if options.verbose: + print "Reading samples from", options.from_file + + if options.log and not options.from_file: + usrp_sink = gr.file_sink(gr.sizeof_gr_complex, 'usrp.dat') + self.connect(self.src, usrp_sink) + + # Set up 22KHz-wide bandpass about center frequency. Decimate by 10 + # to get channel rate of 25Ksps + taps = optfir.low_pass(1.0, # Filter gain + 250e3, # Sample rate + 11000, # One-sided modulation bandwidth + 12500, # One-sided channel bandwidth + 0.1, # Passband ripple + 60) # Stopband attenuation + + if options.verbose: + print "Channel filter has", len(taps), "taps." + + self.chan = gr.freq_xlating_fir_filter_ccf(10, # Decimation rate + taps, # Filter taps + 0.0, # Offset frequency + 250e3) # Sample rate + + if options.log: + chan_sink = gr.file_sink(gr.sizeof_gr_complex, 'chan.dat') + self.connect(self.chan, chan_sink) + + # FLEX protocol demodulator + self.flex = pager.flex_demod(queue, options.frequency, options.verbose, options.log) + + self.connect(self.src, self.chan, self.flex) + + def freq_offset(self): + return self.flex.dc_offset()*1600 + + def adjust_freq(self): + if time.time() - self.adj_time > 1.6: # Only do it once per FLEX frame + self.adj_time = time.time() + self.offset -= self.freq_offset() + self.chan.set_center_freq(self.offset) + if self.verbose: + print "Channel frequency offset (Hz):", int(self.offset) + +def main(): + parser = OptionParser(option_class=eng_option) + parser.add_option("-f", "--frequency", type="eng_float", default=None, + help="set receive frequency to Hz", metavar="Hz") + parser.add_option("-R", "--rx-subdev-spec", type="subdev", + help="select USRP Rx side A or B", metavar="SUBDEV") + parser.add_option("-c", "--calibration", type="eng_float", default=0.0, + help="set frequency offset to Hz", metavar="Hz") + parser.add_option("-g", "--gain", type="int", default=None, + help="set RF gain", metavar="dB") + parser.add_option("-l", "--log", action="store_true", default=False, + help="log flowgraph to files (LOTS of data)") + parser.add_option("-v", "--verbose", action="store_true", default=False, + help="display debug output") + parser.add_option("-F", "--from-file", default=None, + help="read samples from file instead of USRP") + (options, args) = parser.parse_args() + + if len(args) > 0 or (options.frequency == None and options.from_file == None): + print "Run 'usrp_flex.py -h' for options." + sys.exit(1) + + if options.frequency == None: + options.frequency = 0.0 + + # Flow graph emits pages into message queue + queue = gr.msg_queue() + tb = app_top_block(options, queue) + runner = pager.queue_runner(queue) + + try: + tb.run() + except KeyboardInterrupt: + pass + + runner.end() + + +if __name__ == "__main__": + main() |