Hi Tom,
I tried it out but its not working. I am always getting an S which means
overrun. I am attaching the all the files that I have used to make USRP2
work as receiver. I have made no changes to benchmark_tx.py as it is used
for USRP1 and its working correctly.
benchmark_rx.py:
#!/usr/bin/env python
#
# Copyright 2005,2006,2007 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 usrp2
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_usrp2 import receive_path
import fusb_options
#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.rxpath = receive_path(demodulator, rx_callback, options)
self.connect(self.rxpath)
#
/////////////////////////////////////////////////////////////////////////////
# 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()),))
receive_path.add_options(parser, expert_grp)
for mod in demods.values():
mod.add_options(expert_grp)
fusb_options.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
receive_path.py:
#!/usr/bin/env python
#
# Copyright 2005,2006,2007 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, blks2
from gnuradio import usrp2
from gnuradio import eng_notation
import copy
import sys
# from current dir
from pick_bitrate import pick_rx_bitrate
#
/////////////////////////////////////////////////////////////////////////////
# receive path
#
/////////////////////////////////////////////////////////////////////////////
class receive_path(gr.hier_block2):
def __init__(self, demod_class, rx_callback, options):
gr.hier_block2.__init__(self, "receive_path",
gr.io_signature(0, 0, 0), # Input signature
gr.io_signature(0, 0, 0)) # Output signature
options = copy.copy(options) # make a copy so we can
destructively modify
self._interface = options.interface # the USRP
board attached
self._mac_addr = options.mac_addr
self._verbose = options.verbose
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._bitrate = options.bitrate # desired bit
rate
self._decim = options.decim # Decimating rate
for the USRP (prelim)
self._samples_per_symbol = options.samples_per_symbol # desired
samples/symbol
self._fusb_block_size = options.fusb_block_size # usb info for
USRP
self._fusb_nblocks = options.fusb_nblocks # usb info for
USRP
self._rx_callback = rx_callback # this callback is fired when
there's a packet available
self._demod_class = demod_class # the demodulator_class we're
using
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; also adjusts decim, samples_per_symbol, and
bitrate
self._setup_usrp_source()
g = self.u.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 RF frequency
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)
# copy the final answers back into options for use by demodulator
options.samples_per_symbol = self._samples_per_symbol
options.bitrate = self._bitrate
options.decim = self._decim
# Get demod_kwargs
demod_kwargs =
self._demod_class.extract_kwargs_from_options(options)
# Fix USRP2 -> USRP1 scaling
self.scale = gr.multiply_const_cc(32768)
# Design filter to get actual channel we want
sw_decim = 1
chan_coeffs = gr.firdes.low_pass (1.0, # gain
sw_decim *
self._samples_per_symbol, # sampling rate
1.0, # midpoint
of trans. band
0.5, # width of
trans. band
gr.firdes.WIN_HANN) # filter
type
# Decimating channel filter
# complex in and out, float taps
self.chan_filt = gr.fft_filter_ccc(sw_decim, chan_coeffs)
#self.chan_filt = gr.fir_filter_ccf(sw_decim, chan_coeffs)
# receiver
self.packet_receiver = \
blks2.demod_pkts(self._demod_class(**demod_kwargs),
access_code=None,
callback=self._rx_callback,
threshold=-1)
# Carrier Sensing Blocks
alpha = 0.001
thresh = 30 # in dB, will have to adjust
if options.log_rx_power == True:
self.probe = gr.probe_avg_mag_sqrd_cf(thresh,alpha)
self.power_sink = gr.file_sink(gr.sizeof_float, "rxpower.dat")
self.connect(self.chan_filt, self.probe, self.power_sink)
else:
self.probe = gr.probe_avg_mag_sqrd_c(thresh,alpha)
self.connect(self.chan_filt, self.probe)
# Display some information about the setup
if self._verbose:
self._print_verbage()
self.connect(self.u, self.scale, self.chan_filt,
self.packet_receiver)
def _setup_usrp_source(self):
self.u = usrp2.source_32fc (self._interface, self._mac_addr)
adc_rate = self.u.adc_rate()
# derive values of bitrate, samples_per_symbol, and decim from
desired info
(self._bitrate, self._samples_per_symbol, self._decim) = \
pick_rx_bitrate(self._bitrate,
self._demod_class.bits_per_symbol(), \
self._samples_per_symbol, self._decim, adc_rate)
self.u.set_decim(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.set_center_freq(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.u.gain_range()
gain = (r[0] + r[1])/2 # set gain to midpoint
self.gain = gain
return self.u.set_gain(gain)
def set_auto_tr(self, enable):
#return self.u.set_auto_tr(enable)
return
def bitrate(self):
return self._bitrate
def samples_per_symbol(self):
return self._samples_per_symbol
def decim(self):
return self._decim
def carrier_sensed(self):
"""
Return True if we think carrier is present.
"""
#return self.probe.level() > X
return self.probe.unmuted()
def carrier_threshold(self):
"""
Return current setting in dB.
"""
return self.probe.threshold()
def set_carrier_threshold(self, threshold_in_db):
"""
Set carrier threshold.
@param threshold_in_db: set detection threshold
@type threshold_in_db: float (dB)
"""
self.probe.set_threshold(threshold_in_db)
def add_options(normal, expert):
"""
Adds receiver-specific options to the Options Parser
"""
add_freq_option(normal)
if not normal.has_option("--bitrate"):
normal.add_option("-r", "--bitrate", type="eng_float",
default=None,
help="specify bitrate. samples-per-symbol and
interp/decim will be derived.")
normal.add_option("-e", "--interface", type="string",
default="eth0",
help="select Ethernet interface, default is eth0")
normal.add_option("-m", "--mac-addr", type="string", default="",
help="select USRP by MAC address, default is
auto-select")
#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("-S", "--samples-per-symbol", type="int",
default=None,
help="set samples/symbol [default=%default]")
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=None,
help="set fpga decimation rate to DECIM
[default=%default]")
expert.add_option("", "--log", action="store_true", default=False,
help="Log all parts of flow graph to files
(CAUTION: lots of data)")
expert.add_option("", "--log-rx-power", action="store_true",
default=False,
help="Log receive signal power to file (CAUTION:
lots of data)")
# Make a static method to call before instantiation
add_options = staticmethod(add_options)
def _print_verbage(self):
"""
Prints information about the receive path
"""
print "\nReceive Path:"
print "Using RX d'board %s" % (self.u.daughterboard_id(),)
print "Rx gain: %g" % (self.gain,)
print "modulation: %s" % (self._demod_class.__name__)
print "bitrate: %sb/s" %
(eng_notation.num_to_str(self._bitrate))
print "samples/symbol: %3d" % (self._samples_per_symbol)
print "decim: %3d" % (self._decim)
print "Rx Frequency: %s" %
(eng_notation.num_to_str(self._rx_freq))
# print "Rx Frequency: %f" % (self._rx_freq)
def __del__(self):
# Avoid weak reference error
#del self.subdev
return
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")
tunnel_usrp2.py:
#!/usr/bin/env python
#
# Copyright 2005,2006 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.
#
#
/////////////////////////////////////////////////////////////////////////////
#
# This code sets up up a virtual ethernet interface (typically gr0),
# and relays packets between the interface and the GNU Radio PHY+MAC
#
# What this means in plain language, is that if you've got a couple
# of USRPs on different machines, and if you run this code on those
# machines, you can talk between them using normal TCP/IP networking.
#
#
/////////////////////////////////////////////////////////////////////////////
from gnuradio import gr, gru, modulation_utils
from gnuradio import usrp2
from gnuradio import eng_notation
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import random
import time
import struct
import sys
import os
# from current dir
from transmit_path import transmit_path
from receive_path import receive_path
import fusb_options
#print os.getpid()
#raw_input('Attach and press enter')
#
/////////////////////////////////////////////////////////////////////////////
#
# Use the Universal TUN/TAP device driver to move packets to/from kernel
#
# See /usr/src/linux/Documentation/networking/tuntap.txt
#
#
/////////////////////////////////////////////////////////////////////////////
# Linux specific...
# TUNSETIFF ifr flags from <linux/tun_if.h>
IFF_TUN = 0x0001 # tunnel IP packets
IFF_TAP = 0x0002 # tunnel ethernet frames
IFF_NO_PI = 0x1000 # don't pass extra packet info
IFF_ONE_QUEUE = 0x2000 # beats me ;)
def open_tun_interface(tun_device_filename):
from fcntl import ioctl
mode = IFF_TAP | IFF_NO_PI
TUNSETIFF = 0x400454ca
tun = os.open(tun_device_filename, os.O_RDWR)
ifs = ioctl(tun, TUNSETIFF, struct.pack("16sH", "gr%d", mode))
ifname = ifs[:16].strip("\x00")
return (tun, ifname)
#
/////////////////////////////////////////////////////////////////////////////
# the flow graph
#
/////////////////////////////////////////////////////////////////////////////
class my_top_block(gr.top_block):
def __init__(self, mod_class, demod_class,
rx_callback, options):
gr.top_block.__init__(self)
self.txpath = transmit_path(mod_class, options)
self.rxpath = receive_path(demod_class, rx_callback, options)
self.connect(self.txpath);
self.connect(self.rxpath);
def send_pkt(self, payload='', eof=False):
return self.txpath.send_pkt(payload, eof)
def carrier_sensed(self):
"""
Return True if the receive path thinks there's carrier
"""
return self.rxpath.carrier_sensed()
#
/////////////////////////////////////////////////////////////////////////////
# Carrier Sense MAC
#
/////////////////////////////////////////////////////////////////////////////
class cs_mac(object):
"""
Prototype carrier sense MAC
Reads packets from the TUN/TAP interface, and sends them to the PHY.
Receives packets from the PHY via phy_rx_callback, and sends them
into the TUN/TAP interface.
Of course, we're not restricted to getting packets via TUN/TAP, this
is just an example.
"""
def __init__(self, tun_fd, verbose=False):
self.tun_fd = tun_fd # file descriptor for TUN/TAP interface
self.verbose = verbose
self.tb = None # top block (access to PHY)
def set_top_block(self, tb):
self.tb = tb
def phy_rx_callback(self, ok, payload):
"""
Invoked by thread associated with PHY to pass received packet up.
@param ok: bool indicating whether payload CRC was OK
@param payload: contents of the packet (string)
"""
if self.verbose:
print "Rx: ok = %r len(payload) = %4d" % (ok, len(payload))
if ok:
os.write(self.tun_fd, payload)
def main_loop(self):
"""
Main loop for MAC.
Only returns if we get an error reading from TUN.
FIXME: may want to check for EINTR and EAGAIN and reissue read
"""
min_delay = 0.001 # seconds
while 1:
payload = os.read(self.tun_fd, 10*1024)
if not payload:
self.tb.send_pkt(eof=True)
break
if self.verbose:
print "Tx: len(payload) = %4d" % (len(payload),)
delay = min_delay
while self.tb.carrier_sensed():
sys.stderr.write('B')
time.sleep(delay)
if delay < 0.050:
delay = delay * 2 # exponential back-off
self.tb.send_pkt(payload)
#
/////////////////////////////////////////////////////////////////////////////
# main
#
/////////////////////////////////////////////////////////////////////////////
def main():
mods = modulation_utils.type_1_mods()
demods = modulation_utils.type_1_demods()
parser = OptionParser (option_class=eng_option,
conflict_handler="resolve")
expert_grp = parser.add_option_group("Expert")
parser.add_option("-m", "--modulation", type="choice",
choices=mods.keys(),
default='gmsk',
help="Select modulation from: %s [default=%%default]"
% (', '.join(mods.keys()),))
parser.add_option("-v","--verbose", action="store_true", default=False)
expert_grp.add_option("-c", "--carrier-threshold", type="eng_float",
default=30,
help="set carrier detect threshold (dB)
[default=%default]")
expert_grp.add_option("","--tun-device-filename",
default="/dev/net/tun",
help="path to tun device file [default=%default]")
transmit_path.add_options(parser, expert_grp)
receive_path.add_options(parser, expert_grp)
for mod in mods.values():
mod.add_options(expert_grp)
for demod in demods.values():
demod.add_options(expert_grp)
fusb_options.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 or options.tx_freq is None:
sys.stderr.write("You must specify -f FREQ or --freq FREQ\n")
parser.print_help(sys.stderr)
sys.exit(1)
# open the TUN/TAP interface
(tun_fd, tun_ifname) = open_tun_interface(options.tun_device_filename)
# 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"
# If the user hasn't set the fusb_* parameters on the command line,
# pick some values that will reduce latency.
if options.fusb_block_size == 0 and options.fusb_nblocks == 0:
if realtime: # be more aggressive
options.fusb_block_size = gr.prefs().get_long('fusb',
'rt_block_size', 1024)
options.fusb_nblocks = gr.prefs().get_long('fusb',
'rt_nblocks', 16)
else:
options.fusb_block_size = gr.prefs().get_long('fusb',
'block_size', 4096)
options.fusb_nblocks = gr.prefs().get_long('fusb', 'nblocks',
16)
#print "fusb_block_size =", options.fusb_block_size
#print "fusb_nblocks =", options.fusb_nblocks
# instantiate the MAC
mac = cs_mac(tun_fd, verbose=True)
# build the graph (PHY)
tb = my_top_block(mods[options.modulation],
demods[options.modulation],
mac.phy_rx_callback,
options)
mac.set_top_block(tb) # give the MAC a handle for the PHY
if tb.txpath.bitrate() != tb.rxpath.bitrate():
print "WARNING: Transmit bitrate = %sb/sec, Receive bitrate =
%sb/sec" % (
eng_notation.num_to_str(tb.txpath.bitrate()),
eng_notation.num_to_str(tb.rxpath.bitrate()))
print "modulation: %s" % (options.modulation,)
print "freq: %s" %
(eng_notation.num_to_str(options.tx_freq))
print "bitrate: %sb/sec" %
(eng_notation.num_to_str(tb.txpath.bitrate()),)
print "samples/symbol: %3d" % (tb.txpath.samples_per_symbol(),)
#print "interp: %3d" % (tb.txpath.interp(),)
#print "decim: %3d" % (tb.rxpath.decim(),)
tb.rxpath.set_carrier_threshold(options.carrier_threshold)
print "Carrier sense threshold:", options.carrier_threshold, "dB"
print
print "Allocated virtual ethernet interface: %s" % (tun_ifname,)
print "You must now use ifconfig to set its IP address. E.g.,"
print
print " $ sudo ifconfig %s 192.168.200.1" % (tun_ifname,)
print
print "Be sure to use a different address in the same subnet for each
machine."
print
tb.start() # Start executing the flow graph (runs in separate
threads)
mac.main_loop() # don't expect this to return...
tb.stop() # but if it does, tell flow graph to stop.
tb.wait() # wait for it to finish
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
pass
Please let me know if I am missing out something in the code. Also can you
let me know where am I suppose to use blks2.rational_resampler_ccf in the
code. Thanks in advance.
With regards,
Smith
Tom Rondeau wrote:
>
> Smith L. wrote:
>> Hi,
>>
>> I have been trying to use USRP2 as a receiver and USRP1 as a transmitter.
>> The benchmark_tx.py file is working well for USRP1 but I did some
>> modifications to benchmark_rx.py so that it can work on USRP2. But it
>> didnt
>> worked out. Can anyone help me with this modifcations so that I can
>> establish communication between USRP1 and USRP2. Thanks in advance.
>>
>
> You have to watch out for the different sample rates. When you set the
> sample rate in benchmark_tx/rx, it finds the closest sampling rate it
> can get through the interpolation/decimation factor in the USRP. Since
> the USRP and USRP2 have different speed DACs/ADCs, the exact values are
> going to be different.
>
> Run both with the -v option to see what the actual sample rate both the
> tx and rx side are using. To fix this, either try to find a rate that
> works for both USRP and USRP2, or, and this is a better solution, use a
> blks2.rational_resampler_ccf to resample to achieve closer sampling
> rates in both tx and rx.
>
> Tom
>
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> Discuss-gnuradio@gnu.org
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>
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