--- /dev/null
+#!/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()
projects / debian / gnuradio / blobdiff