#!/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 from usrpm import usrp_dbid 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("-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, io_type=uhd.io_type.COMPLEX_FLOAT32, num_channels=1) 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) if(options.antenna): self.u.set_antenna(options.antenna, 0) 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 ()