From ae30f247616b6229fb304e30fecf3f82ae09dbf6 Mon Sep 17 00:00:00 2001 From: Ben Reynwar <ben@reynwar.net> Date: Thu, 7 Mar 2013 23:27:44 -0700 Subject: analog: Enabling uninstalled python imports. --- gr-analog/python/analog/nbfm_tx.py | 93 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 gr-analog/python/analog/nbfm_tx.py (limited to 'gr-analog/python/analog/nbfm_tx.py') diff --git a/gr-analog/python/analog/nbfm_tx.py b/gr-analog/python/analog/nbfm_tx.py new file mode 100644 index 0000000000..62b56bae52 --- /dev/null +++ b/gr-analog/python/analog/nbfm_tx.py @@ -0,0 +1,93 @@ +# +# Copyright 2005,2012 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 GNU Radio; see the file COPYING. If not, write to +# the Free Software Foundation, Inc., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + +import math +from gnuradio import gr, filter +from fm_emph import fm_preemph + +try: + from gnuradio import analog +except ImportError: + import analog_swig as analog + +class nbfm_tx(gr.hier_block2): + def __init__(self, audio_rate, quad_rate, tau=75e-6, max_dev=5e3): + """ + Narrow Band FM Transmitter. + + Takes a single float input stream of audio samples in the range [-1,+1] + and produces a single FM modulated complex baseband output. + + Args: + audio_rate: sample rate of audio stream, >= 16k (integer) + quad_rate: sample rate of output stream (integer) + tau: preemphasis time constant (default 75e-6) (float) + max_dev: maximum deviation in Hz (default 5e3) (float) + + quad_rate must be an integer multiple of audio_rate. + """ + + gr.hier_block2.__init__(self, "nbfm_tx", + gr.io_signature(1, 1, gr.sizeof_float), # Input signature + gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature + + # FIXME audio_rate and quad_rate ought to be exact rationals + audio_rate = int(audio_rate) + quad_rate = int(quad_rate) + + if quad_rate % audio_rate != 0: + raise ValueError, "quad_rate is not an integer multiple of audio_rate" + + + do_interp = audio_rate != quad_rate + + if do_interp: + interp_factor = quad_rate / audio_rate + interp_taps = filter.optfir.low_pass(interp_factor, # gain + quad_rate, # Fs + 4500, # passband cutoff + 7000, # stopband cutoff + 0.1, # passband ripple dB + 40) # stopband atten dB + + #print "len(interp_taps) =", len(interp_taps) + self.interpolator = filter.interp_fir_filter_fff (interp_factor, interp_taps) + + self.preemph = fm_preemph(quad_rate, tau=tau) + + k = 2 * math.pi * max_dev / quad_rate + self.modulator = analog.frequency_modulator_fc(k) + + if do_interp: + self.connect(self, self.interpolator, self.preemph, self.modulator, self) + else: + self.connect(self, self.preemph, self.modulator, self) + + +class ctcss_gen_f(gr.hier_block2): + def __init__(self, sample_rate, tone_freq): + gr.hier_block2.__init__(self, "ctcss_gen_f", + gr.io_signature(0, 0, 0), # Input signature + gr.io_signature(1, 1, gr.sizeof_float)) # Output signature + + self.plgen = analog.sig_source_f(sample_rate, analog.GR_SIN_WAVE, + tone_freq, 0.1, 0.0) + self.connect(self.plgen, self) -- cgit v1.2.3