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#!/usr/bin/env python
#
# Copyright 2006,2007,2009,2011 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, uhd, optfir, eng_notation, pager
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import time, os, sys
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
self.u = uhd.usrp_source(device_addr=options.address, stream_args=uhd.stream_args('fc32'))
# Grab 250 KHz of spectrum
# (A UHD facility to get sample rate range and granularity would be useful)
self.u.set_samp_rate(250e3)
rate = self.u.get_samp_rate()
if rate != 250e3:
print "Unable to set required sample rate of 250 Ksps (got %f)" % rate
sys.exit(1)
# Tune daughterboard
r = self.u.set_center_freq(options.freq+options.calibration, 0)
if not r:
frange = self.u.get_freq_range()
sys.stderr.write(("\nRequested frequency (%f) out or range [%f, %f]\n") % \
(freq, frange.start(), frange.stop()))
sys.exit(1)
# if no gain was specified, use the mid-point in dB
if options.rx_gain is None:
grange = self.u.get_gain_range()
options.rx_gain = float(grange.start()+grange.stop())/2.0
print "\nNo gain specified."
print "Setting gain to %f (from [%f, %f])" % \
(options.rx_gain, grange.start(), grange.stop())
self.u.set_gain(options.rx_gain, 0)
else:
# Use supplied file as source of samples
self.u = 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.u, 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.freq, options.verbose, options.log)
self.connect(self.u, 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 get_options():
parser = OptionParser(option_class=eng_option)
parser.add_option('-f', '--freq', type="eng_float", default=None,
help="Set receive frequency to FREQ [default=%default]",
metavar="FREQ")
parser.add_option("-a", "--address", type="string", default="addr=192.168.10.2",
help="Address of UHD device, [default=%default]")
parser.add_option("-A", "--antenna", type="string", default=None,
help="select Rx Antenna where appropriate")
parser.add_option("", "--rx-gain", type="eng_float", default=None,
help="set receive gain in dB (default is midpoint)")
parser.add_option("-c", "--calibration", type="eng_float", default=0.0,
help="set frequency offset to Hz", metavar="Hz")
parser.add_option("-v", "--verbose", action="store_true", default=False)
parser.add_option("-l", "--log", action="store_true", default=False,
help="log flowgraph to files (LOTS of data)")
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:
print "Run 'usrp_flex.py -h' for options."
sys.exit(1)
if (options.freq is None):
sys.stderr.write("You must specify -f FREQ or --freq FREQ\n")
sys.exit(1)
return (options, args)
if __name__ == "__main__":
(options, args) = get_options()
# 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()
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