diff options
| author | jcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5> | 2006-08-03 04:51:51 +0000 |
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| committer | jcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5> | 2006-08-03 04:51:51 +0000 |
| commit | 5d69a524f81f234b3fbc41d49ba18d6f6886baba (patch) | |
| tree | b71312bf7f1e8d10fef0f3ac6f28784065e73e72 /gnuradio-examples/python/mc4020 | |
Houston, we have a trunk.
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@3122 221aa14e-8319-0410-a670-987f0aec2ac5
Diffstat (limited to 'gnuradio-examples/python/mc4020')
| -rw-r--r-- | gnuradio-examples/python/mc4020/Makefile.am | 28 | ||||
| -rwxr-xr-x | gnuradio-examples/python/mc4020/fm_demod.py | 150 | ||||
| -rwxr-xr-x | gnuradio-examples/python/mc4020/mc4020_fft.py | 53 |
3 files changed, 231 insertions, 0 deletions
diff --git a/gnuradio-examples/python/mc4020/Makefile.am b/gnuradio-examples/python/mc4020/Makefile.am new file mode 100644 index 0000000000..21bed3e469 --- /dev/null +++ b/gnuradio-examples/python/mc4020/Makefile.am @@ -0,0 +1,28 @@ +# +# Copyright 2004 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 2, 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., 59 Temple Place - Suite 330, +# Boston, MA 02111-1307, USA. +# + +EXTRA_DIST = \ + fm_demod.py \ + mc4020_fft.py + + + + diff --git a/gnuradio-examples/python/mc4020/fm_demod.py b/gnuradio-examples/python/mc4020/fm_demod.py new file mode 100755 index 0000000000..e58407f738 --- /dev/null +++ b/gnuradio-examples/python/mc4020/fm_demod.py @@ -0,0 +1,150 @@ +#!/usr/bin/env python + +from gnuradio import gr +from gnuradio import audio +from gnuradio import mc4020 +import sys + +def high_speed_adc (fg, input_rate): + # return gr.file_source (gr.sizeof_short, "dummy.dat", False) + return mc4020.source (input_rate, mc4020.MCC_CH3_EN | mc4020.MCC_ALL_1V) + +# +# return a gr.flow_graph +# +def build_graph (freq1, freq2): + input_rate = 20e6 + cfir_decimation = 125 + audio_decimation = 5 + + quad_rate = input_rate / cfir_decimation + audio_rate = quad_rate / audio_decimation + + fg = gr.flow_graph () + + # use high speed ADC as input source + src = high_speed_adc (fg, input_rate) + + # compute FIR filter taps for channel selection + channel_coeffs = \ + gr.firdes.low_pass (1.0, # gain + input_rate, # sampling rate + 250e3, # low pass cutoff freq + 8*100e3, # width of trans. band + gr.firdes.WIN_HAMMING) + + # input: short; output: complex + chan_filter1 = \ + gr.freq_xlating_fir_filter_scf (cfir_decimation, + channel_coeffs, + freq1, # 1st station freq + input_rate) + + (head1, tail1) = build_pipeline (fg, quad_rate, audio_decimation) + + # sound card as final sink + audio_sink = audio.sink (int (audio_rate)) + + # now wire it all together + fg.connect (src, chan_filter1) + fg.connect (chan_filter1, head1) + fg.connect (tail1, (audio_sink, 0)) + + # two stations at once? + if freq2: + # Extract the second station and connect + # it to a second pipeline... + + # input: short; output: complex + chan_filter2 = \ + gr.freq_xlating_fir_filter_scf (cfir_decimation, + channel_coeffs, + freq2, # 2nd station freq + input_rate) + + (head2, tail2) = build_pipeline (fg, quad_rate, audio_decimation) + + fg.connect (src, chan_filter2) + fg.connect (chan_filter2, head2) + fg.connect (tail2, (audio_sink, 1)) + + return fg + +def build_pipeline (fg, quad_rate, audio_decimation): + '''Given a flow_graph, fg, construct a pipeline + for demodulating a broadcast FM signal. The + input is the downconverteed complex baseband + signal. The output is the demodulated audio. + + build_pipeline returns a two element tuple + containing the input and output endpoints. + ''' + fm_demod_gain = 2200.0/32768.0 + audio_rate = quad_rate / audio_decimation + volume = 1.0 + + # input: complex; output: float + fm_demod = gr.quadrature_demod_cf (volume*fm_demod_gain) + + # compute FIR filter taps for audio filter + width_of_transition_band = audio_rate / 32 + audio_coeffs = gr.firdes.low_pass (1.0, # gain + quad_rate, # sampling rate + audio_rate/2 - width_of_transition_band, + width_of_transition_band, + gr.firdes.WIN_HAMMING) + + # input: float; output: float + audio_filter = gr.fir_filter_fff (audio_decimation, audio_coeffs) + + fg.connect (fm_demod, audio_filter) + return ((fm_demod, 0), (audio_filter, 0)) + + +def main (args): + nargs = len (args) + if nargs == 1: + freq1 = float (args[0]) * 1e6 + freq2 = None + elif nargs == 2: + freq1 = float (args[0]) * 1e6 + freq2 = float (args[1]) * 1e6 + else: + sys.stderr.write ('usage: fm_demod freq1 [freq2]\n') + sys.exit (1) + + # connect to RF front end + rf_front_end = gr.microtune_4937_eval_board () + if not rf_front_end.board_present_p (): + raise IOError, 'RF front end not found' + + # set front end gain + rf_front_end.set_AGC (300) + IF_freq = rf_front_end.get_output_freq () + IF_freq = 5.75e6 + + if not freq2: # one station + + rf_front_end.set_RF_freq (freq1) + fg = build_graph (IF_freq, None) + + else: # two stations + + if abs (freq1 - freq2) > 5.5e6: + raise IOError, 'freqs too far apart' + + target_freq = (freq1 + freq2) / 2 + actual_freq = rf_front_end.set_RF_freq (target_freq) + #actual_freq = target_freq + + fg = build_graph (IF_freq + freq1 - actual_freq, + IF_freq + freq2 - actual_freq) + + fg.start () # fork thread(s) and return + raw_input ('Press Enter to quit: ') + fg.stop () + +if __name__ == '__main__': + main (sys.argv[1:]) + + diff --git a/gnuradio-examples/python/mc4020/mc4020_fft.py b/gnuradio-examples/python/mc4020/mc4020_fft.py new file mode 100755 index 0000000000..3348ad4f6b --- /dev/null +++ b/gnuradio-examples/python/mc4020/mc4020_fft.py @@ -0,0 +1,53 @@ +#!/usr/bin/env python +# +# Copyright 2004 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 2, 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., 59 Temple Place - Suite 330, +# Boston, MA 02111-1307, USA. +# + +from gnuradio import gr +from gnuradio import mc4020 +from gnuradio.eng_option import eng_option +from gnuradio.wxgui import stdgui, fftsink +from optparse import OptionParser +import wx + +class app_flow_graph (stdgui.gui_flow_graph): + def __init__(self, frame, panel, vbox, argv): + stdgui.gui_flow_graph.__init__ (self, frame, panel, vbox, argv) + + + parser = OptionParser (option_class=eng_option) + (options, args) = parser.parse_args () + + input_rate = 20e6 + src = mc4020.source (input_rate, mc4020.MCC_CH3_EN | mc4020.MCC_ALL_1V) + cvt = gr.short_to_float () + block, fft_win = fftsink.make_fft_sink_f (self, panel, "Rx Data", 512, input_rate) + + self.connect (src, cvt) + self.connect (cvt, block) + vbox.Add (fft_win, 1, wx.EXPAND) + + +def main (): + app = stdgui.stdapp (app_flow_graph, "USRP FFT") + app.MainLoop () + +if __name__ == '__main__': + main () |