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#!/usr/bin/env python
#
# Copyright 2005-2007,2011 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, optfir, audio, blks2, uhd
from gnuradio import eng_notation
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import sys
class wfm_rx_block (gr.top_block):
def __init__(self):
gr.top_block.__init__(self)
parser=OptionParser(option_class=eng_option)
parser.add_option("-a", "--args", type="string", default="",
help="UHD device address args [default=%default]")
parser.add_option("", "--spec", type="string", default=None,
help="Subdevice of UHD device where appropriate")
parser.add_option("-A", "--antenna", type="string", default=None,
help="select Rx Antenna where appropriate")
parser.add_option("-f", "--freq", type="eng_float", default=100.1e6,
help="set frequency to FREQ", metavar="FREQ")
parser.add_option("-g", "--gain", type="eng_float", default=None,
help="set gain in dB (default is midpoint)")
parser.add_option("-V", "--volume", type="eng_float", default=None,
help="set volume (default is midpoint)")
parser.add_option("-O", "--audio-output", type="string", default="",
help="pcm device name. E.g., hw:0,0 or surround51 or /dev/dsp")
parser.add_option("", "--freq-min", type="eng_float", default=87.9e6,
help="Set a minimum frequency [default=%default]")
parser.add_option("", "--freq-max", type="eng_float", default=108.1e6,
help="Set a maximum frequency [default=%default]")
(options, args) = parser.parse_args()
if len(args) != 0:
parser.print_help()
sys.exit(1)
self.state = "FREQ"
self.freq = 0
self.fm_freq_min = options.freq_min
self.fm_freq_max = options.freq_max
# build graph
self.u = uhd.usrp_source(device_addr=options.args,
io_type=uhd.io_type.COMPLEX_FLOAT32,
num_channels=1)
usrp_rate = 320e3
demod_rate = 320e3
audio_rate = 32e3
audio_decim = int(demod_rate / audio_rate)
self.u.set_samp_rate(usrp_rate)
dev_rate = self.u.get_samp_rate()
nfilts = 32
chan_coeffs = optfir.low_pass (nfilts, # gain
nfilts*usrp_rate, # sampling rate
80e3, # passband cutoff
115e3, # stopband cutoff
0.1, # passband ripple
60) # stopband attenuation
rrate = usrp_rate / dev_rate
self.chan_filt = blks2.pfb_arb_resampler_ccf(rrate, chan_coeffs, nfilts)
self.guts = blks2.wfm_rcv (demod_rate, audio_decim)
self.volume_control = gr.multiply_const_ff(1)
# sound card as final sink
self.audio_sink = audio.sink(int(audio_rate),
options.audio_output,
False) # ok_to_block
# now wire it all together
self.connect (self.u, self.chan_filt, self.guts,
self.volume_control, self.audio_sink)
if options.gain is None:
# if no gain was specified, use the mid-point in dB
g = self.u.get_gain_range()
options.gain = float(g.start()+g.stop())/2.0
if options.volume is None:
g = self.volume_range()
options.volume = float(g[0]+g[1])/2
frange = self.u.get_freq_range()
if(frange.start() > self.fm_freq_max or frange.stop() < self.fm_freq_min):
sys.stderr.write("Radio does not support required frequency range.\n")
sys.exit(1)
if(options.freq < self.fm_freq_min or options.freq > self.fm_freq_max):
sys.stderr.write("Requested frequency is outside of required frequency range.\n")
sys.exit(1)
# set initial values
self.set_gain(options.gain)
self.set_vol(options.volume)
if not(self.set_freq(options.freq)):
self._set_status_msg("Failed to set initial frequency")
# Set the subdevice spec
if(options.spec):
self.u.set_subdev_spec(options.spec, 0)
# Set the antenna
if(options.antenna):
self.u.set_antenna(options.antenna, 0)
def set_vol (self, vol):
g = self.volume_range()
self.vol = max(g[0], min(g[1], vol))
self.volume_control.set_k(10**(self.vol/10))
self.update_status_bar ()
def set_freq(self, target_freq):
"""
Set the center frequency we're interested in.
@param target_freq: frequency in Hz
@rypte: bool
"""
r = self.u.set_center_freq(target_freq)
if r:
self.freq = target_freq
self.update_status_bar()
self._set_status_msg("OK", 0)
return True
self._set_status_msg("Failed", 0)
return False
def set_gain(self, gain):
self.u.set_gain(gain)
def update_status_bar (self):
msg = "Freq: %s Volume:%f Setting:%s" % (
eng_notation.num_to_str(self.freq), self.vol, self.state)
self._set_status_msg(msg, 1)
def _set_status_msg(self, msg, which=0):
print msg
def volume_range(self):
return (-20.0, 0.0, 0.5)
if __name__ == '__main__':
tb = wfm_rx_block()
try:
tb.run()
except KeyboardInterrupt:
pass
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