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#!/usr/bin/env python
#
# Copyright 2005,2006,2007,2009 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.
#
from gnuradio import gr, gru, modulation_utils
from gnuradio import usrp
from gnuradio import eng_notation
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import random
import struct
import sys
# from current dir
from receive_path import receive_path
#import os
#print os.getpid()
#raw_input('Attach and press enter: ')
class my_top_block(gr.top_block):
def __init__(self, demodulator, rx_callback, options):
gr.top_block.__init__(self)
self._rx_freq = options.rx_freq # receiver's center frequency
self._rx_gain = options.rx_gain # receiver's gain
self._rx_subdev_spec = options.rx_subdev_spec # daughterboard to use
self._decim = options.decim # Decimating rate for the USRP (prelim)
if self._rx_freq is None:
sys.stderr.write("-f FREQ or --freq FREQ or --rx-freq FREQ must be specified\n")
raise SystemExit
# Set up USRP source
self._setup_usrp_source()
ok = self.set_freq(self._rx_freq)
if not ok:
print "Failed to set Rx frequency to %s" % (eng_notation.num_to_str(self._rx_freq))
raise ValueError, eng_notation.num_to_str(self._rx_freq)
g = self.subdev.gain_range()
if options.show_rx_gain_range:
print "Rx Gain Range: minimum = %g, maximum = %g, step size = %g" \
% (g[0], g[1], g[2])
self.set_gain(options.rx_gain)
self.set_auto_tr(True) # enable Auto Transmit/Receive switching
# Set up receive path
self.rxpath = receive_path(demodulator, rx_callback, options)
self.connect(self.u, self.rxpath)
def _setup_usrp_source(self):
self.u = usrp.source_c ()
adc_rate = self.u.adc_rate()
self.u.set_decim_rate(self._decim)
# determine the daughterboard subdevice we're using
if self._rx_subdev_spec is None:
self._rx_subdev_spec = usrp.pick_rx_subdevice(self.u)
self.subdev = usrp.selected_subdev(self.u, self._rx_subdev_spec)
self.u.set_mux(usrp.determine_rx_mux_value(self.u, self._rx_subdev_spec))
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.
"""
r = self.u.tune(0, self.subdev, target_freq)
if r:
return True
return False
def set_gain(self, gain):
"""
Sets the analog gain in the USRP
"""
if gain is None:
r = self.subdev.gain_range()
gain = (r[0] + r[1])/2 # set gain to midpoint
self.gain = gain
return self.subdev.set_gain(gain)
def set_auto_tr(self, enable):
return self.subdev.set_auto_tr(enable)
def decim(self):
return self._decim
def add_options(normal, expert):
"""
Adds usrp-specific options to the Options Parser
"""
add_freq_option(normal)
normal.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
help="select USRP Rx side A or B")
normal.add_option("", "--rx-gain", type="eng_float", default=None, metavar="GAIN",
help="set receiver gain in dB [default=midpoint]. See also --show-rx-gain-range")
normal.add_option("", "--show-rx-gain-range", action="store_true", default=False,
help="print min and max Rx gain available on selected daughterboard")
normal.add_option("-v", "--verbose", action="store_true", default=False)
expert.add_option("", "--rx-freq", type="eng_float", default=None,
help="set Rx frequency to FREQ [default=%default]", metavar="FREQ")
expert.add_option("-d", "--decim", type="intx", default=128,
help="set fpga decimation rate to DECIM [default=%default]")
expert.add_option("", "--snr", type="eng_float", default=30,
help="set the SNR of the channel in dB [default=%default]")
# Make a static method to call before instantiation
add_options = staticmethod(add_options)
def add_freq_option(parser):
"""
Hackery that has the -f / --freq option set both tx_freq and rx_freq
"""
def freq_callback(option, opt_str, value, parser):
parser.values.rx_freq = value
parser.values.tx_freq = value
if not parser.has_option('--freq'):
parser.add_option('-f', '--freq', type="eng_float",
action="callback", callback=freq_callback,
help="set Tx and/or Rx frequency to FREQ [default=%default]",
metavar="FREQ")
# /////////////////////////////////////////////////////////////////////////////
# main
# /////////////////////////////////////////////////////////////////////////////
global n_rcvd, n_right
def main():
global n_rcvd, n_right
n_rcvd = 0
n_right = 0
def rx_callback(ok, payload):
global n_rcvd, n_right
(pktno,) = struct.unpack('!H', payload[0:2])
n_rcvd += 1
if ok:
n_right += 1
print "ok = %5s pktno = %4d n_rcvd = %4d n_right = %4d" % (
ok, pktno, n_rcvd, n_right)
demods = modulation_utils.type_1_demods()
# Create Options Parser:
parser = OptionParser (option_class=eng_option, conflict_handler="resolve")
expert_grp = parser.add_option_group("Expert")
parser.add_option("-m", "--modulation", type="choice", choices=demods.keys(),
default='gmsk',
help="Select modulation from: %s [default=%%default]"
% (', '.join(demods.keys()),))
my_top_block.add_options(parser, expert_grp)
receive_path.add_options(parser, expert_grp)
for mod in demods.values():
mod.add_options(expert_grp)
(options, args) = parser.parse_args ()
if len(args) != 0:
parser.print_help(sys.stderr)
sys.exit(1)
if options.rx_freq is None:
sys.stderr.write("You must specify -f FREQ or --freq FREQ\n")
parser.print_help(sys.stderr)
sys.exit(1)
# build the graph
tb = my_top_block(demods[options.modulation], rx_callback, options)
r = gr.enable_realtime_scheduling()
if r != gr.RT_OK:
print "Warning: Failed to enable realtime scheduling."
tb.start() # start flow graph
tb.wait() # wait for it to finish
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
pass
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