diff options
Diffstat (limited to 'gr-uhd/examples/python/usrp_wfm_rcv_sca.py')
| -rwxr-xr-x | gr-uhd/examples/python/usrp_wfm_rcv_sca.py | 403 |
1 files changed, 0 insertions, 403 deletions
diff --git a/gr-uhd/examples/python/usrp_wfm_rcv_sca.py b/gr-uhd/examples/python/usrp_wfm_rcv_sca.py deleted file mode 100755 index 4c6aec23f..000000000 --- a/gr-uhd/examples/python/usrp_wfm_rcv_sca.py +++ /dev/null @@ -1,403 +0,0 @@ -#!/usr/bin/env python -# -# Copyright 2006,2007,2011 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 this program; if not, write to the Free Software Foundation, Inc., -# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. -# - -""" -Here is a bit of code that will receive SCA analog subcarriers of FM -Broadcast Stations using the USRP. It is a modified version of -usrp_wfm_rcv.py. - -Common SCA frequencies are 67 kHz and 92 kHz. SCA is used for Reading -Services for the Blind, Background Music, Foreign Language Services, and -other services. Remember you may hear static when tuned to a FM station -because this code only outputs SCA audio. - -The USRP gain is critical for good decoding. Adjust for minimum noise. - I use the Post FM Demod FFT to check for SCA subcarriers and to adjust -the USRP gain for the lowest noise floor. The stereo pilot at 19 KHz, -the stereo difference signal around 38 KHz, and RDS at 57 KHz are also -displayed on the Post FM Demod FFT if present. - -The range below 67 kHz is used for SCA only when Stereo is not used. - -The SCA recieve range is not as far as the main FM carrier receive range -so tune in strong local stations first. - -I tried to comment the code with the various parameters. There seems to -be several choices for a couple of them. I coded the common ones I see -here. - -In the local area there are a couple of stations using digital SCA. -These look similar to narrow DRM signals and I wonder if they are using -OFDM. -""" - - -from gnuradio import gr, optfir, audio, blks2, uhd -from gnuradio.eng_option import eng_option -from gnuradio.wxgui import slider, powermate -from gnuradio.wxgui import stdgui2, fftsink2, form -from optparse import OptionParser -import sys -import math -import wx - -class wfm_rx_sca_block (stdgui2.std_top_block): - def __init__(self,frame,panel,vbox,argv): - stdgui2.std_top_block.__init__ (self,frame,panel,vbox,argv) - - 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="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.frame = frame - self.panel = panel - - self.vol = 0 - 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, stream_args=uhd.stream_args('fc32')) - - # 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) - - usrp_rate = 320e3 - demod_rate = 320e3 - audio_rate = 32e3 - sca_demod_rate = 64e3 - audio_decim = int(demod_rate / audio_rate) - sca_chanfilt_decim = int(demod_rate / sca_demod_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 - 100e3, # passband cutoff - 140e3, # 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) - - #Create demodulator block for Main FM Channel - max_dev = 75e3 - fm_demod_gain = demod_rate/(2*math.pi*max_dev) - self.fm_demod = gr.quadrature_demod_cf (fm_demod_gain) - - # Note - deemphasis is not applied to the Main FM Channel as - # main audio is not decoded - - # SCA Devation is 10% of carrier but some references say 20% - # if mono with one SCA (6 KHz seems typical) - max_sca_dev = 6e3 - - # Create filter to get SCA channel we want - sca_chan_coeffs = gr.firdes.low_pass (1.0, # gain - demod_rate, # sampling rate - max_sca_dev, # cutoff freq - max_sca_dev/3, # trans. band - gr.firdes.WIN_HANN) # filter type - - self.ddc = gr.freq_xlating_fir_filter_fcf(sca_chanfilt_decim, # decim rate - sca_chan_coeffs, # taps - 0, # freq translation amount (Gets set by the UI) - demod_rate) # input sample rate - - #Create demodulator block for SCA Channel - sca_demod_gain = sca_demod_rate/(2*math.pi*max_sca_dev) - self.fm_demod_sca = gr.quadrature_demod_cf (sca_demod_gain) - - - # SCA analog audio is bandwidth limited to 5 KHz - max_sca_audio_freq = 5.0e3 - - # SCA analog deephasis is 150 uS (75 uS may be used) - sca_tau = 150e-6 - - # compute FIR filter taps for SCA audio filter - audio_coeffs = gr.firdes.low_pass (1.0, # gain - sca_demod_rate, # sampling rate - max_sca_audio_freq, # cutoff freq - max_sca_audio_freq/2.5, # trans. band - gr.firdes.WIN_HAMMING) - - # input: float; output: float - self.audio_filter = gr.fir_filter_fff (audio_decim, audio_coeffs) - - # Create deemphasis block that is applied after SCA demodulation - self.deemph = blks2.fm_deemph (audio_rate, sca_tau) - - self.volume_control = gr.multiply_const_ff(self.vol) - - # 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.fm_demod, - self.ddc, self.fm_demod_sca) - self.connect (self.fm_demod_sca, self.audio_filter, - self.deemph, self.volume_control, - self.audio_sink) - - self._build_gui(vbox, usrp_rate, demod_rate, sca_demod_rate, audio_rate) - - 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 - - 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") - self.set_sca_freq(67000) # A common SCA Frequency - - def _set_status_msg(self, msg, which=0): - self.frame.GetStatusBar().SetStatusText(msg, which) - - - def _build_gui(self, vbox, usrp_rate, demod_rate, sca_demod_rate, audio_rate): - - def _form_set_freq(kv): - return self.set_freq(kv['freq']) - - def _form_set_sca_freq(kv): - return self.set_sca_freq(kv['sca_freq']) - - if 1: - self.src_fft = fftsink2.fft_sink_c(self.panel, title="Data from USRP", - fft_size=512, sample_rate=usrp_rate, - ref_scale=32768.0, ref_level=0, y_divs=12) - self.connect (self.u, self.src_fft) - vbox.Add (self.src_fft.win, 4, wx.EXPAND) - - if 1: - post_demod_fft = fftsink2.fft_sink_f(self.panel, title="Post FM Demod", - fft_size=2048, sample_rate=demod_rate, - y_per_div=10, ref_level=0) - self.connect (self.fm_demod, post_demod_fft) - vbox.Add (post_demod_fft.win, 4, wx.EXPAND) - - if 0: - post_demod_sca_fft = fftsink2.fft_sink_f(self.panel, title="Post SCA Demod", - fft_size=1024, sample_rate=sca_demod_rate, - y_per_div=10, ref_level=0) - self.connect (self.fm_demod_sca, post_demod_sca_fft) - vbox.Add (post_demod_sca_fft.win, 4, wx.EXPAND) - - if 0: - post_deemph_fft = fftsink2.fft_sink_f (self.panel, title="Post SCA Deemph", - fft_size=512, sample_rate=audio_rate, - y_per_div=10, ref_level=-20) - self.connect (self.deemph, post_deemph_fft) - vbox.Add (post_deemph_fft.win, 4, wx.EXPAND) - - - # control area form at bottom - self.myform = myform = form.form() - - hbox = wx.BoxSizer(wx.HORIZONTAL) - hbox.Add((5,0), 0) - myform['freq'] = form.float_field( - parent=self.panel, sizer=hbox, label="Freq", weight=1, - callback=myform.check_input_and_call(_form_set_freq, self._set_status_msg)) - - hbox.Add((5,0), 0) - myform['freq_slider'] = \ - form.quantized_slider_field(parent=self.panel, sizer=hbox, weight=3, - range=(self.fm_freq_min, self.fm_freq_max, 0.1e6), - callback=self.set_freq) - hbox.Add((5,0), 0) - vbox.Add(hbox, 0, wx.EXPAND) - - hbox = wx.BoxSizer(wx.HORIZONTAL) - hbox.Add((5,0), 0) - myform['sca_freq'] = form.float_field( - parent=self.panel, sizer=hbox, label="SCA", weight=1, - callback=myform.check_input_and_call(_form_set_sca_freq, self._set_status_msg)) - - hbox.Add((5,0), 0) - myform['sca_freq_slider'] = \ - form.quantized_slider_field(parent=self.panel, sizer=hbox, weight=3, - range=(38e3, 100e3, 1.0e3), - callback=self.set_sca_freq) - hbox.Add((5,0), 0) - vbox.Add(hbox, 0, wx.EXPAND) - - hbox = wx.BoxSizer(wx.HORIZONTAL) - hbox.Add((5,0), 0) - - myform['volume'] = \ - form.quantized_slider_field(parent=self.panel, sizer=hbox, label="Volume", - weight=3, range=self.volume_range(), - callback=self.set_vol) - hbox.Add((5,0), 1) - - g = self.u.get_gain_range() - myform['gain'] = \ - form.quantized_slider_field(parent=self.panel, sizer=hbox, label="Gain", - weight=3, range=(g.start(), g.stop(), g.step()), - callback=self.set_gain) - hbox.Add((5,0), 0) - vbox.Add(hbox, 0, wx.EXPAND) - - try: - self.knob = powermate.powermate(self.frame) - self.rot = 0 - powermate.EVT_POWERMATE_ROTATE (self.frame, self.on_rotate) - powermate.EVT_POWERMATE_BUTTON (self.frame, self.on_button) - except: - print "FYI: No Powermate or Contour Knob found" - - - def on_rotate (self, event): - self.rot += event.delta - if (self.state == "FREQ"): - if self.rot >= 3: - self.set_freq(self.freq + .1e6) - self.rot -= 3 - elif self.rot <=-3: - self.set_freq(self.freq - .1e6) - self.rot += 3 - else: - step = self.volume_range()[2] - if self.rot >= 3: - self.set_vol(self.vol + step) - self.rot -= 3 - elif self.rot <=-3: - self.set_vol(self.vol - step) - self.rot += 3 - - def on_button (self, event): - if event.value == 0: # button up - return - self.rot = 0 - if self.state == "FREQ": - self.state = "VOL" - else: - self.state = "FREQ" - self.update_status_bar () - - - 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.myform['volume'].set_value(self.vol) - 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 - - Tuning is a two step process. First we ask the front-end to - tune as close to the desired frequency as it can. Then we use - the result of that operation and our target_frequency to - determine the value for the digital down converter. - """ - r = self.u.set_center_freq(target_freq) - if r: - self.freq = target_freq - self.myform['freq'].set_value(target_freq) # update displayed value - self.myform['freq_slider'].set_value(target_freq) # update displayed value - self.update_status_bar() - self._set_status_msg("OK", 0) - return True - self._set_status_msg("Failed", 0) - return False - - def set_sca_freq(self, target_sca_freq): - - self.ddc.set_center_freq(-target_sca_freq) - self.myform['sca_freq'].set_value(target_sca_freq) # update displayed value - self.myform['sca_freq_slider'].set_value(target_sca_freq) # update displayed value - self.update_status_bar() - self._set_status_msg("OK", 0) - return True - - def set_gain(self, gain): - self.myform['gain'].set_value(gain) # update displayed value - self.u.set_gain(gain) - - def update_status_bar (self): - msg = "Volume:%r Setting:%s" % (self.vol, self.state) - self._set_status_msg(msg, 1) - self.src_fft.set_baseband_freq(self.freq) - - def volume_range(self): - return (-20.0, 0.0, 0.5) - - -if __name__ == '__main__': - app = stdgui2.stdapp (wfm_rx_sca_block, "USRP WFM SCA RX") - app.MainLoop () |