git.gag.com Git - debian/gnuradio/blob - gnuradio-examples/python/usrp/usrp_wfm_rcv2_nogui.py

   1 #!/usr/bin/env python
   2
   3 from gnuradio import gr, gru, eng_notation, optfir
   4 from gnuradio import audio
   5 from gnuradio import usrp
   6 from gnuradio import blks
   7 from gnuradio.eng_option import eng_option
   8 from optparse import OptionParser
   9 import usrp_dbid
  10 import sys
  11 import math
  12
  13 def pick_subdevice(u):
  14     """
  15     The user didn't specify a subdevice on the command line.
  16     Try for one of these, in order: TV_RX, BASIC_RX, whatever is on side A.
  17
  18     @return a subdev_spec
  19     """
  20     return usrp.pick_subdev(u, (usrp_dbid.TV_RX,
  21                                 usrp_dbid.TV_RX_REV_2,
  22                                 usrp_dbid.BASIC_RX))
  23
  24
  25 class wfm_rx_graph (gr.flow_graph):
  26
  27     def __init__(self):
  28         gr.flow_graph.__init__(self)
  29
  30         parser=OptionParser(option_class=eng_option)
  31         parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
  32                           help="select USRP Rx side A or B (default=A)")
  33         parser.add_option("", "--f1", type="eng_float", default=100.7e6,
  34                           help="set 1st station frequency to FREQ", metavar="FREQ")
  35         parser.add_option("", "--f2", type="eng_float", default=102.5e6,
  36                           help="set 2nd station freq to FREQ", metavar="FREQ")
  37         parser.add_option("-g", "--gain", type="eng_float", default=40,
  38                           help="set gain in dB (default is midpoint)")
  39         parser.add_option("-O", "--audio-output", type="string", default="",
  40                           help="pcm device name.  E.g., hw:0,0 or surround51 or /dev/dsp")
  41
  42         (options, args) = parser.parse_args()
  43         if len(args) != 0:
  44             parser.print_help()
  45             sys.exit(1)
  46
  47         if abs(options.f1) < 1e6:
  48             options.f1 *= 1e6
  49
  50         if abs(options.f2) < 1e6:
  51             options.f2 *= 1e6
  52
  53         if abs(options.f1 - options.f2) > 5.5e6:
  54             print "Sorry, two stations must be within 5.5MHz of each other"
  55             raise SystemExit
  56
  57         f = (options.f1, options.f2)
  58
  59         self.vol = .1
  60         self.state = "FREQ"
  61
  62         # build graph
  63
  64         self.u = usrp.source_c(0, nchan=2)          # usrp is data source
  65
  66         adc_rate = self.u.adc_rate()                # 64 MS/s
  67         usrp_decim = 200
  68         self.u.set_decim_rate(usrp_decim)
  69         usrp_rate = adc_rate / usrp_decim           # 320 kS/s
  70         chanfilt_decim = 1
  71         demod_rate = usrp_rate / chanfilt_decim
  72         audio_decimation = 10
  73         audio_rate = demod_rate / audio_decimation  # 32 kHz
  74
  75
  76         if options.rx_subdev_spec is None:
  77             options.rx_subdev_spec = pick_subdevice(self.u)
  78
  79         mv = usrp.determine_rx_mux_value(self.u, options.rx_subdev_spec)
  80         mv |= (mv << 8) & 0xff00   # both DDC inputs setup same way
  81         self.u.set_mux(mv)
  82         self.subdev = usrp.selected_subdev(self.u, options.rx_subdev_spec)
  83         print "Using RX d'board %s" % (self.subdev.side_and_name(),)
  84
  85
  86         # deinterleave two channels from FPGA
  87         di = gr.deinterleave(gr.sizeof_gr_complex)
  88
  89         # wire up the head of the chain
  90         self.connect(self.u, di)
  91
  92         # sound card as final sink
  93         audio_sink = audio.sink(int(audio_rate), options.audio_output)
  94
  95         # taps for channel filter
  96         chan_filt_coeffs = optfir.low_pass (1,           # gain
  97                                             usrp_rate,   # sampling rate
  98                                             80e3,        # passband cutoff
  99                                             115e3,       # stopband cutoff
 100                                             0.1,         # passband ripple
 101                                             60)          # stopband attenuation
 102         #print len(chan_filt_coeffs)
 103
 104         mid_freq = (f[0] + f[1]) / 2
 105         # set front end PLL to middle frequency
 106         ok, baseband_freq = self.subdev.set_freq(mid_freq)
 107
 108         for n in range(2):
 109             chan_filt = gr.fir_filter_ccf (chanfilt_decim, chan_filt_coeffs)
 110             guts = blks.wfm_rcv (self, demod_rate, audio_decimation)
 111             volume_control = gr.multiply_const_ff(self.vol)
 112             self.connect((di, n), chan_filt)
 113             self.connect(chan_filt, guts, volume_control)
 114             self.connect(volume_control, (audio_sink, n))
 115             dxc_freq, inverted = usrp.calc_dxc_freq(f[n], baseband_freq,
 116                                                     self.u.converter_rate())
 117             self.u.set_rx_freq(n, dxc_freq)
 118
 119
 120         if options.gain is None:
 121             # if no gain was specified, use the mid-point in dB
 122             g = self.subdev.gain_range()
 123             options.gain = float(g[0]+g[1])/2
 124
 125
 126         # set initial values
 127         self.set_gain(options.gain)
 128
 129
 130     def set_vol (self, vol):
 131         self.vol = vol
 132         self.volume_control.set_k(self.vol)
 133
 134
 135     def set_gain(self, gain):
 136         self.subdev.set_gain(gain)
 137
 138
 139 if __name__ == '__main__':
 140     fg = wfm_rx_graph()
 141     try:
 142         fg.run()
 143     except KeyboardInterrupt:
 144         pass