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#!/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 ()
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