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Diffstat (limited to 'gr-uhd/examples/python/fm_tx4.py')
| -rwxr-xr-x | gr-uhd/examples/python/fm_tx4.py | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/gr-uhd/examples/python/fm_tx4.py b/gr-uhd/examples/python/fm_tx4.py new file mode 100755 index 000000000..aecb35b54 --- /dev/null +++ b/gr-uhd/examples/python/fm_tx4.py @@ -0,0 +1,208 @@ +#!/usr/bin/env python +# +# Copyright 2005-2007,2011 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 GNU Radio; see the file COPYING. If not, write to +# the Free Software Foundation, Inc., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + +""" +Transmit N simultaneous narrow band FM signals. + +They will be centered at the frequency specified on the command line, +and will spaced at 25kHz steps from there. + +The program opens N files with names audio-N.dat where N is in [0,7]. +These files should contain floating point audio samples in the range [-1,1] +sampled at 32kS/sec. You can create files like this using +audio_to_file.py +""" + +from gnuradio import gr, eng_notation +from gnuradio import uhd +from gnuradio import blks2 +from gnuradio.eng_option import eng_option +from optparse import OptionParser +import math +import sys + +from gnuradio.wxgui import stdgui2, fftsink2 +import wx + + +######################################################## +# instantiate one transmit chain for each call + +class pipeline(gr.hier_block2): + def __init__(self, filename, lo_freq, audio_rate, if_rate): + + gr.hier_block2.__init__(self, "pipeline", + gr.io_signature(0, 0, 0), + gr.io_signature(1, 1, gr.sizeof_gr_complex)) + + try: + src = gr.file_source (gr.sizeof_float, filename, True) + except RuntimeError: + sys.stderr.write(("\nError: Could not open file '%s'\n\n" % \ + filename)) + sys.exit(1) + + print audio_rate, if_rate + fmtx = blks2.nbfm_tx (audio_rate, if_rate, max_dev=5e3, tau=75e-6) + + # Local oscillator + lo = gr.sig_source_c (if_rate, # sample rate + gr.GR_SIN_WAVE, # waveform type + lo_freq, #frequency + 1.0, # amplitude + 0) # DC Offset + mixer = gr.multiply_cc () + + self.connect (src, fmtx, (mixer, 0)) + self.connect (lo, (mixer, 1)) + self.connect (mixer, self) + +class fm_tx_block(stdgui2.std_top_block): + def __init__(self, frame, panel, vbox, argv): + MAX_CHANNELS = 7 + 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("-s", "--samp-rate", type="eng_float", default=400e3, + help="set sample rate (bandwidth) [default=%default]") + parser.add_option("-f", "--freq", type="eng_float", default=None, + 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("-n", "--nchannels", type="int", default=4, + help="number of Tx channels [1,4]") + #parser.add_option("","--debug", action="store_true", default=False, + # help="Launch Tx debugger") + (options, args) = parser.parse_args () + + if len(args) != 0: + parser.print_help() + sys.exit(1) + + if options.nchannels < 1 or options.nchannels > MAX_CHANNELS: + sys.stderr.write ("fm_tx4: nchannels out of range. Must be in [1,%d]\n" % MAX_CHANNELS) + sys.exit(1) + + if options.freq is None: + sys.stderr.write("fm_tx4: must specify frequency with -f FREQ\n") + parser.print_help() + sys.exit(1) + + # ---------------------------------------------------------------- + # Set up constants and parameters + + self.u = uhd.usrp_sink(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) + + self.usrp_rate = options.samp_rate + self.u.set_samp_rate(self.usrp_rate) + self.usrp_rate = self.u.get_samp_rate() + + self.sw_interp = 10 + self.audio_rate = self.usrp_rate / self.sw_interp # 32 kS/s + + 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 + + self.set_gain(options.gain) + self.set_freq(options.freq) + + self.sum = gr.add_cc () + + # Instantiate N NBFM channels + step = 25e3 + offset = (0 * step, 1 * step, -1 * step, + 2 * step, -2 * step, 3 * step, -3 * step) + + for i in range (options.nchannels): + t = pipeline("audio-%d.dat" % (i % 4), offset[i], + self.audio_rate, self.usrp_rate) + self.connect(t, (self.sum, i)) + + self.gain = gr.multiply_const_cc (1.0 / options.nchannels) + + # connect it all + self.connect (self.sum, self.gain) + self.connect (self.gain, self.u) + + # plot an FFT to verify we are sending what we want + if 1: + post_mod = fftsink2.fft_sink_c(panel, title="Post Modulation", + fft_size=512, + sample_rate=self.usrp_rate, + y_per_div=20, + ref_level=40) + self.connect (self.gain, post_mod) + vbox.Add (post_mod.win, 1, wx.EXPAND) + + + #if options.debug: + # self.debugger = tx_debug_gui.tx_debug_gui(self.subdev) + # self.debugger.Show(True) + + + 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 up converter. Finally, we feed + any residual_freq to the s/w freq translater. + """ + + r = self.u.set_center_freq(target_freq, 0) + if r: + print "Frequency =", eng_notation.num_to_str(self.u.get_center_freq()) + return True + + return False + + def set_gain(self, gain): + self.u.set_gain(gain, 0) + + +def main (): + app = stdgui2.stdapp(fm_tx_block, "Multichannel FM Tx", nstatus=1) + app.MainLoop () + +if __name__ == '__main__': + main () |