diff --git a/src/demod/python/rtlsdr-tetra_demod_fft.py b/src/demod/python/rtlsdr-tetra_demod_fft.py index 49cf2a0..3930533 100755 --- a/src/demod/python/rtlsdr-tetra_demod_fft.py +++ b/src/demod/python/rtlsdr-tetra_demod_fft.py @@ -2,12 +2,14 @@ # Copyright 2012 Dimitri Stolnikov -# Call it with -# src$ ./demod/python/rtlsdr-tetra_demod_fft.py -s 1.8e6 -f 394.6e6 -g -1 -o /dev/stdout | ./float_to_bits /dev/stdin /dev/stdout | ./tetra-rx /dev/stdin +# Usage: +# src$ ./demod/python/rtlsdr-tetra_demod_fft.py -o /dev/stdout | ./float_to_bits /dev/stdin /dev/stdout | ./tetra-rx /dev/stdin # # Adjust the center frequency (-f) and gain (-g) according to your needs. -# Use left click in Full Spectrum window to roughly select a TETRA carrier. -# Use left click to fine tune the carrier by clicking on the left or right side of the spectrum. +# Use left click in Wideband Spectrum window to roughly select a TETRA carrier. +# In Wideband Spectrum you can also tune by 1/4 of the bandwidth by clicking on the rightmost/leftmost spectrum side. +# Use left click in Channel Spectrum windows to fine tune the carrier by clicking on the left or right side of the spectrum. + import sys import math @@ -15,6 +17,7 @@ from gnuradio import gr, gru, audio, eng_notation, blks2, optfir from gnuradio import audio from gnuradio.eng_option import eng_option from gnuradio.wxgui import fftsink2 +from gnuradio.wxgui import forms from grc_gnuradio import wxgui as grc_wxgui from optparse import OptionParser import osmosdr @@ -33,37 +36,42 @@ class top_block(grc_wxgui.top_block_gui): options = get_options() + self.ifreq = options.frequency + self.rfgain = options.gain + self.src = osmosdr.source_c() - self.src.set_center_freq(options.frequency) + self.src.set_center_freq(self.ifreq) self.src.set_sample_rate(int(options.sample_rate)) - if options.gain is None: + if self.rfgain is None: self.src.set_gain_mode(1) + self.iagc = 1 + self.rfgain = 0 else: + self.iagc = 0 self.src.set_gain_mode(0) - self.src.set_gain(options.gain) + self.src.set_gain(self.rfgain) # may differ from the requested rate sample_rate = self.src.get_sample_rate() symbol_rate = 18000 sps = 2 # output rate will be 36,000 - new_sample_rate = symbol_rate * sps + out_sample_rate = symbol_rate * sps options.low_pass = options.low_pass / 2.0 - taps = gr.firdes.low_pass(1.0, sample_rate, options.low_pass, options.low_pass * 0.2, gr.firdes.WIN_HANN) - first_decim = 10 self.offset = 0 + taps = gr.firdes.low_pass(1.0, sample_rate, options.low_pass, options.low_pass * 0.2, gr.firdes.WIN_HANN) self.tuner = gr.freq_xlating_fir_filter_ccf(first_decim, taps, self.offset, sample_rate) sys.stderr.write("sample rate: %d\n" % (sample_rate)) self.demod = cqpsk.cqpsk_demod( - samples_per_symbol = sps, + samples_per_symbol = sps, excess_bw=0.35, costas_alpha=0.03, gain_mu=0.05, @@ -74,29 +82,98 @@ class top_block(grc_wxgui.top_block_gui): self.output = gr.file_sink(gr.sizeof_float, options.output_file) - rerate = float(sample_rate / float(first_decim)) / float(new_sample_rate) + rerate = float(sample_rate / float(first_decim)) / float(out_sample_rate) sys.stderr.write("resampling factor: %f\n" % rerate) - #self.resamp = gr.fractional_interpolator_cc(0, rerate) - self.resamp = blks2.pfb_arb_resampler_ccf(1 / rerate) + if rerate.is_integer(): + sys.stderr.write("using pfb decimator\n") + self.resamp = blks2.pfb_decimator_ccf(int(rerate)) + else: + sys.stderr.write("using pfb resampler\n") + self.resamp = blks2.pfb_arb_resampler_ccf(1 / rerate) self.connect(self.src, self.tuner, self.resamp, self.demod, self.output) + def set_ifreq(ifreq): + self.ifreq = ifreq + self._ifreq_text_box.set_value(self.ifreq) + self.src.set_center_freq(self.ifreq) + + self._ifreq_text_box = forms.text_box( + parent=self.GetWin(), + value=self.ifreq, + callback=set_ifreq, + label="Center Frequency", + converter=forms.float_converter(), + ) + self.Add(self._ifreq_text_box) + + def set_iagc(iagc): + self.iagc = iagc + self._agc_check_box.set_value(self.iagc) + self.src.set_gain_mode(self.iagc, 0) + self.src.set_gain(0 if self.iagc == 1 else self.rfgain, 0) + + self._agc_check_box = forms.check_box( + parent=self.GetWin(), + value=self.iagc, + callback=set_iagc, + label="Automatic Gain", + true=1, + false=0, + ) + + self.Add(self._agc_check_box) + + def set_rfgain(rfgain): + self.rfgain = rfgain + self._rfgain_slider.set_value(self.rfgain) + self._rfgain_text_box.set_value(self.rfgain) + self.src.set_gain(0 if self.iagc == 1 else self.rfgain, 0) + + _rfgain_sizer = wx.BoxSizer(wx.VERTICAL) + self._rfgain_text_box = forms.text_box( + parent=self.GetWin(), + sizer=_rfgain_sizer, + value=self.rfgain, + callback=set_rfgain, + label="RF Gain", + converter=forms.float_converter(), + proportion=0, + ) + self._rfgain_slider = forms.slider( + parent=self.GetWin(), + sizer=_rfgain_sizer, + value=self.rfgain, + callback=set_rfgain, + minimum=0, + maximum=50, + num_steps=200, + style=wx.SL_HORIZONTAL, + cast=float, + proportion=1, + ) + + self.Add(_rfgain_sizer) + def fftsink2_callback(x, y): - sys.stderr.write("selected channel at offset: %d Hz\n" % x) - self.offset = -x - self.tuner.set_center_freq(self.offset) + if abs(x / (sample_rate / 2)) > 0.9: + set_ifreq(self.ifreq + x / 2) + else: + sys.stderr.write("coarse tuned to: %d Hz\n" % x) + self.offset = -x + self.tuner.set_center_freq(self.offset) self.scope = fftsink2.fft_sink_c(self.GetWin(), - title="Full Spectrum (click to coarse tune)", - fft_size=1024, - sample_rate=sample_rate, - ref_scale=2.0, - ref_level=-30, - y_divs=10, - fft_rate=10, - average=False, - avg_alpha=0.6) + title="Wideband Spectrum (click to coarse tune)", + fft_size=1024, + sample_rate=sample_rate, + ref_scale=2.0, + ref_level=0, + y_divs=10, + fft_rate=10, + average=False, + avg_alpha=0.6) self.Add(self.scope.win) self.scope.set_callback(fftsink2_callback) @@ -104,20 +181,20 @@ class top_block(grc_wxgui.top_block_gui): self.connect(self.src, self.scope) def fftsink2_callback2(x, y): - sys.stderr.write("fine tuning channel: %d Hz\n" % x) - self.offset = self.offset - (x / 10) + self.offset = self.offset - (x / 10) + sys.stderr.write("fine tuned to: %d Hz\n" % self.offset) self.tuner.set_center_freq(self.offset) self.scope2 = fftsink2.fft_sink_c(self.GetWin(), - title="Narrow Spectrum (click to fine tune)", - fft_size=1024, - sample_rate=new_sample_rate, #sample_rate / first_decim, - ref_scale=2.0, - ref_level=-30, - y_divs=10, - fft_rate=10, - average=False, - avg_alpha=0.6) + title="Channel Spectrum (click to fine tune)", + fft_size=1024, + sample_rate=out_sample_rate, + ref_scale=2.0, + ref_level=-20, + y_divs=10, + fft_rate=10, + average=False, + avg_alpha=0.6) self.Add(self.scope2.win) self.scope2.set_callback(fftsink2_callback2) @@ -129,7 +206,7 @@ def get_options(): parser.add_option("-s", "--sample-rate", type="eng_float", default=1800000, help="set receiver sample rate (default 1800000)") - parser.add_option("-f", "--frequency", type="eng_float", default=394.6e9, + parser.add_option("-f", "--frequency", type="eng_float", default=394.6e6, help="set receiver center frequency") parser.add_option("-g", "--gain", type="eng_float", default=None, help="set receiver gain")