/usr/bin/osmocom_spectrum_sense is in gr-osmosdr 0.1.4-14build1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 | #!/usr/bin/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.
#
import osmosdr
from gnuradio import gr, eng_notation
from gnuradio import blocks
from gnuradio import audio
from gnuradio import filter
from gnuradio import fft
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import sys
import math
import struct
import threading
from datetime import datetime
sys.stderr.write("Warning: this may have issues on some machines+Python version combinations to seg fault due to the callback in bin_statitics.\n\n")
class ThreadClass(threading.Thread):
def run(self):
return
class tune(gr.feval_dd):
"""
This class allows C++ code to callback into python.
"""
def __init__(self, tb):
gr.feval_dd.__init__(self)
self.tb = tb
def eval(self, ignore):
"""
This method is called from blocks.bin_statistics_f when it wants
to change the center frequency. This method tunes the front
end to the new center frequency, and returns the new frequency
as its result.
"""
try:
# We use this try block so that if something goes wrong
# from here down, at least we'll have a prayer of knowing
# what went wrong. Without this, you get a very
# mysterious:
#
# terminate called after throwing an instance of
# 'Swig::DirectorMethodException' Aborted
#
# message on stderr. Not exactly helpful ;)
new_freq = self.tb.set_next_freq()
# wait until msgq is empty before continuing
while(self.tb.msgq.full_p()):
#print "msgq full, holding.."
time.sleep(0.1)
return new_freq
except Exception, e:
print "tune: Exception: ", e
class parse_msg(object):
def __init__(self, msg):
self.center_freq = msg.arg1()
self.vlen = int(msg.arg2())
assert(msg.length() == self.vlen * gr.sizeof_float)
# FIXME consider using NumPy array
t = msg.to_string()
self.raw_data = t
self.data = struct.unpack('%df' % (self.vlen,), t)
class my_top_block(gr.top_block):
def __init__(self):
gr.top_block.__init__(self)
usage = "usage: %prog [options] min_freq max_freq"
parser = OptionParser(option_class=eng_option, usage=usage)
parser.add_option("-a", "--args", type="string", default="",
help="Device args [default=%default]")
parser.add_option("-A", "--antenna", type="string", default=None,
help="Select antenna where appropriate")
parser.add_option("-s", "--samp-rate", type="eng_float", default=None,
help="Set sample rate (bandwidth), minimum by default")
parser.add_option("-g", "--gain", type="eng_float", default=None,
help="Set gain in dB (default is midpoint)")
parser.add_option("", "--tune-delay", type="eng_float",
default=0.25, metavar="SECS",
help="Time to delay (in seconds) after changing frequency [default=%default]")
parser.add_option("", "--dwell-delay", type="eng_float",
default=0.25, metavar="SECS",
help="Time to dwell (in seconds) at a given frequency [default=%default]")
parser.add_option("-b", "--channel-bandwidth", type="eng_float",
default=6.25e3, metavar="Hz",
help="Channel bandwidth of fft bins in Hz [default=%default]")
parser.add_option("-q", "--squelch-threshold", type="eng_float",
default=None, metavar="dB",
help="Squelch threshold in dB [default=%default]")
parser.add_option("-F", "--fft-size", type="int", default=None,
help="Specify number of FFT bins [default=samp_rate/channel_bw]")
parser.add_option("", "--real-time", action="store_true", default=False,
help="Attempt to enable real-time scheduling")
(options, args) = parser.parse_args()
if len(args) != 2:
parser.print_help()
sys.exit(1)
self.channel_bandwidth = options.channel_bandwidth
self.min_freq = eng_notation.str_to_num(args[0])
self.max_freq = eng_notation.str_to_num(args[1])
if self.min_freq > self.max_freq:
# swap them
self.min_freq, self.max_freq = self.max_freq, self.min_freq
if not options.real_time:
realtime = False
else:
# Attempt to enable realtime scheduling
r = gr.enable_realtime_scheduling()
if r == gr.RT_OK:
realtime = True
else:
realtime = False
print "Note: failed to enable realtime scheduling"
# build graph
self.u = osmosdr.source(options.args)
try:
self.u.get_sample_rates().start()
except RuntimeError:
print "Source has no sample rates (wrong device arguments?)."
sys.exit(1)
# Set the antenna
if(options.antenna):
self.u.set_antenna(options.antenna, 0)
if options.samp_rate is None:
options.samp_rate = self.u.get_sample_rates().start()
self.u.set_sample_rate(options.samp_rate)
self.usrp_rate = usrp_rate = self.u.get_sample_rate()
if options.fft_size is None:
self.fft_size = int(self.usrp_rate/self.channel_bandwidth)
else:
self.fft_size = options.fft_size
self.squelch_threshold = options.squelch_threshold
s2v = blocks.stream_to_vector(gr.sizeof_gr_complex, self.fft_size)
mywindow = filter.window.blackmanharris(self.fft_size)
ffter = fft.fft_vcc(self.fft_size, True, mywindow, True)
power = 0
for tap in mywindow:
power += tap*tap
c2mag = blocks.complex_to_mag_squared(self.fft_size)
# FIXME the log10 primitive is dog slow
#log = blocks.nlog10_ff(10, self.fft_size,
# -20*math.log10(self.fft_size)-10*math.log10(power/self.fft_size))
# Set the freq_step to 75% of the actual data throughput.
# This allows us to discard the bins on both ends of the spectrum.
self.freq_step = self.nearest_freq((0.75 * self.usrp_rate), self.channel_bandwidth)
self.min_center_freq = self.min_freq + (self.freq_step/2)
nsteps = math.ceil((self.max_freq - self.min_freq) / self.freq_step)
self.max_center_freq = self.min_center_freq + (nsteps * self.freq_step)
self.next_freq = self.min_center_freq
tune_delay = max(0, int(round(options.tune_delay * usrp_rate / self.fft_size))) # in fft_frames
dwell_delay = max(1, int(round(options.dwell_delay * usrp_rate / self.fft_size))) # in fft_frames
self.msgq = gr.msg_queue(1)
self._tune_callback = tune(self) # hang on to this to keep it from being GC'd
stats = blocks.bin_statistics_f(self.fft_size, self.msgq,
self._tune_callback, tune_delay,
dwell_delay)
# FIXME leave out the log10 until we speed it up
#self.connect(self.u, s2v, ffter, c2mag, log, stats)
self.connect(self.u, s2v, ffter, c2mag, stats)
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())/2.0
self.set_gain(options.gain)
print "gain =", options.gain
def set_next_freq(self):
target_freq = self.next_freq
self.next_freq = self.next_freq + self.freq_step
if self.next_freq >= self.max_center_freq:
self.next_freq = self.min_center_freq
if not self.set_freq(target_freq):
print "Failed to set frequency to", target_freq
sys.exit(1)
return target_freq
def set_freq(self, target_freq):
"""
Set the center frequency we're interested in.
@param target_freq: frequency in Hz
@rypte: bool
"""
r = self.u.set_center_freq(target_freq)
if r:
return True
return False
def set_gain(self, gain):
self.u.set_gain(gain)
def nearest_freq(self, freq, channel_bandwidth):
freq = round(freq / channel_bandwidth, 0) * channel_bandwidth
return freq
def main_loop(tb):
def bin_freq(i_bin, center_freq):
#hz_per_bin = tb.usrp_rate / tb.fft_size
freq = center_freq - (tb.usrp_rate / 2) + (tb.channel_bandwidth * i_bin)
#print "freq original:",freq
#freq = nearest_freq(freq, tb.channel_bandwidth)
#print "freq rounded:",freq
return freq
bin_start = int(tb.fft_size * ((1 - 0.75) / 2))
bin_stop = int(tb.fft_size - bin_start)
while 1:
# Get the next message sent from the C++ code (blocking call).
# It contains the center frequency and the mag squared of the fft
m = parse_msg(tb.msgq.delete_head())
# m.center_freq is the center frequency at the time of capture
# m.data are the mag_squared of the fft output
# m.raw_data is a string that contains the binary floats.
# You could write this as binary to a file.
for i_bin in range(bin_start, bin_stop):
center_freq = m.center_freq
freq = bin_freq(i_bin, center_freq)
#noise_floor_db = -174 + 10*math.log10(tb.channel_bandwidth)
noise_floor_db = 10*math.log10(min(m.data)/tb.usrp_rate)
power_db = 10*math.log10(m.data[i_bin]/tb.usrp_rate) - noise_floor_db
if (power_db > tb.squelch_threshold) and (freq >= tb.min_freq) and (freq <= tb.max_freq):
print datetime.now(), "center_freq", center_freq, "freq", freq, "power_db", power_db, "noise_floor_db", noise_floor_db
if __name__ == '__main__':
t = ThreadClass()
t.start()
tb = my_top_block()
try:
tb.start()
main_loop(tb)
except KeyboardInterrupt:
pass
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