3 # Copyright 2005,2006,2007 Free Software Foundation, Inc.
5 # This file is part of GNU Radio
7 # GNU Radio is free software; you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation; either version 3, or (at your option)
12 # GNU Radio is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with GNU Radio; see the file COPYING. If not, write to
19 # the Free Software Foundation, Inc., 51 Franklin Street,
20 # Boston, MA 02110-1301, USA.
23 from gnuradio import gr, gru, eng_notation, optfir
24 from gnuradio import audio
25 from gnuradio import usrp
26 from gnuradio import blks2
27 from gnuradio.eng_option import eng_option
28 from optparse import OptionParser
29 from usrpm import usrp_dbid
33 def calc_dxc_freq(target_freq, baseband_freq, fs):
34 dxc_temp = (target_freq - baseband_freq) % fs
40 dxc_freq = fs - dxc_temp
43 return (dxc_freq, inverted)
45 def pick_subdevice(u):
47 The user didn't specify a subdevice on the command line.
48 Try for one of these, in order: TV_RX, BASIC_RX, whatever is on side A.
52 return usrp.pick_subdev(u, (usrp_dbid.TV_RX,
53 usrp_dbid.TV_RX_REV_2,
57 class wfm_rx_block (gr.top_block):
60 gr.top_block.__init__(self)
62 parser=OptionParser(option_class=eng_option)
63 parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
64 help="select USRP Rx side A or B (default=A)")
65 parser.add_option("", "--f1", type="eng_float", default=100.7e6,
66 help="set 1st station frequency to FREQ", metavar="FREQ")
67 parser.add_option("", "--f2", type="eng_float", default=102.5e6,
68 help="set 2nd station freq to FREQ", metavar="FREQ")
69 parser.add_option("-g", "--gain", type="eng_float", default=40,
70 help="set gain in dB (default is midpoint)")
71 parser.add_option("-O", "--audio-output", type="string", default="",
72 help="pcm device name. E.g., hw:0,0 or surround51 or /dev/dsp")
74 (options, args) = parser.parse_args()
79 if abs(options.f1) < 1e6:
82 if abs(options.f2) < 1e6:
85 if abs(options.f1 - options.f2) > 5.5e6:
86 print "Sorry, two stations must be within 5.5MHz of each other"
89 f = (options.f1, options.f2)
96 self.u = usrp.source_c(0, nchan=2) # usrp is data source
98 adc_rate = self.u.adc_rate() # 64 MS/s
100 self.u.set_decim_rate(usrp_decim)
101 usrp_rate = adc_rate / usrp_decim # 320 kS/s
103 demod_rate = usrp_rate / chanfilt_decim
104 audio_decimation = 10
105 audio_rate = demod_rate / audio_decimation # 32 kHz
108 if options.rx_subdev_spec is None:
109 options.rx_subdev_spec = pick_subdevice(self.u)
111 mv = usrp.determine_rx_mux_value(self.u, options.rx_subdev_spec)
112 mv |= (mv << 8) & 0xff00 # both DDC inputs setup same way
114 self.subdev = usrp.selected_subdev(self.u, options.rx_subdev_spec)
115 print "Using RX d'board %s" % (self.subdev.side_and_name(),)
118 # deinterleave two channels from FPGA
119 di = gr.deinterleave(gr.sizeof_gr_complex)
121 # wire up the head of the chain
122 self.connect(self.u, di)
124 # sound card as final sink
125 audio_sink = audio.sink(int(audio_rate), options.audio_output)
127 # taps for channel filter
128 chan_filt_coeffs = optfir.low_pass (1, # gain
129 usrp_rate, # sampling rate
130 80e3, # passband cutoff
131 115e3, # stopband cutoff
132 0.1, # passband ripple
133 60) # stopband attenuation
134 #print len(chan_filt_coeffs)
136 mid_freq = (f[0] + f[1]) / 2
137 # set front end PLL to middle frequency
138 tune_result = self.subdev.set_freq(mid_freq)
141 chan_filt = gr.fir_filter_ccf (chanfilt_decim, chan_filt_coeffs)
142 guts = blks2.wfm_rcv (demod_rate, audio_decimation)
143 volume_control = gr.multiply_const_ff(self.vol)
144 self.connect((di, n), chan_filt)
145 self.connect(chan_filt, guts, volume_control)
146 self.connect(volume_control, (audio_sink, n))
147 dxc_freq, inverted = calc_dxc_freq(f[n], tune_result.baseband_freq,
148 self.u.converter_rate())
149 self.u.set_rx_freq(n, dxc_freq)
152 if options.gain is None:
153 # if no gain was specified, use the mid-point in dB
154 g = self.subdev.gain_range()
155 options.gain = float(g[0]+g[1])/2
159 self.set_gain(options.gain)
162 def set_vol (self, vol):
164 self.volume_control.set_k(self.vol)
167 def set_gain(self, gain):
168 self.subdev.set_gain(gain)
171 # Avoid weak-reference error
174 if __name__ == '__main__':
178 except KeyboardInterrupt: