Dear all,
I’m trying to port the Douglas BBN 802.11b code on the USRP2 working
with the last version of GNU-Radio (3.2SVN)
The last version of Douglas bbn 802.11b already work with hier_blok2 but
not with USRP2, so,
in order to do this porting I followed the recommendations below :
http://www.opensubscriber.com/message/[email protected]/9944619.html
I just have modified the files “bbn_80211b_tx.py” and
“bbn_80211b_transmit_path.py” because
it should be by means of these ones that we can access to USRP2.
I obtain the following error:
Traceback (most recent call last):
File “bbn_80211b_tx.py”, line 108, in
main()
File “bbn_80211b_tx.py”, line 72, in main
tb = my_block(options.interp, options.spb, options.barker)
File “bbn_80211b_tx.py”, line 22, in init
self.txpath = bbn_80211b_transmit_path(interp_rate, spb, use_barker)
File
“/home/usrptest1/bbn_80211_doug/src/examples/bbn_80211b_transmit_path.py”,
line 44, in init
self.packet_transmitter = bbn_80211b_mod_pkts(tb, spb=spb,
NameError: global name ‘tb’ is not defined
I am not able to solve this error and debug the new code 
Any suggestion about this porting will be welcome
Best regards Andrea
Here below there are my two modified codes:
##################################################
bbn_802.11b_tx.py
##################################################
from gnuradio import gr, gru, blks2
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
# from current dir
from bbn_80211b_transmit_path import bbn_80211b_transmit_path
class my_block(gr.top_block):
def __init__(self, interp_rate, spb, use_barker):
gr.top_block.__init__(self)
self.txpath = bbn_80211b_transmit_path(interp_rate, spb,
use_barker)
#def init(self, tx_subdev_spec,
interp_rate, spb, use_barker):
# gr.flow_graph.init(self)
# self.txpath = bbn_80211b_transmit_path(tx_subdev_spec,
#interp_rate, spb,
use_barker)
#
/////////////////////////////////////////////////////////////////////////////
# main
/////////////////////////////////////////////////////////////////////////////
def main():
def send_pkt(payload=‘’, eof=False):
return tb.txpath.send_pkt(payload, eof)
def rx_callback(ok, payload):
print “ok = %r, payload = ‘%s’” % (ok, payload)
parser = OptionParser (option_class=eng_option)
#parser.add_option(“-T”, “–tx-subdev-spec”, type=“subdev”,
default=None,
# help=“select USRP Tx side A or B”)
parser.add_option(“-f”, “–freq”, type=“eng_float”,
default=2.4e9,
help=
“set Tx and Rx frequency to FREQ
[default=%default]”,
metavar=“FREQ”)
parser.add_option(“-S”, “–spb”, type=“int”, default=8,
help=“set samples/baud [default=%default]”)
parser.add_option(“-i”, “–interp”, type=“int”, default=32,
help=
“set fpga interpolation rate to INTERP
[default=%default]”)
parser.add_option(“-r”, “–reps”, type=“int”, default=20,
help=
“Number of packets to send
[default=%default]”)
parser.add_option(“-b”, “–barker”, action=“store_true”,
default=False,
help=“Use Barker Spreading
[default=%default]”)
(options, args) = parser.parse_args ()
if len(args) != 0:
parser.print_help()
sys.exit(1)
if options.freq < 1e6:
options.freq *= 1e6
# build the graph
tb = my_block(options.interp, options.spb, options.barker)
#print “bitrate: %sb/sec” %
(eng_notation.num_to_str(tb.txpath.bitrate()),)
print “spb: %3d” % (tb.txpath.spb(),)
print “interp: %3d” % (tb.txpath.interp(),)
ok = tb.txpath.set_freq(options.freq)
if not ok:
print “Failed to set Tx frequency to %s” %
(eng_notation.num_to_str(options.freq),)
raise SystemExit
tb.start() # start flow graph
# generate and send packets
n = 0
fp = open(‘getty.txt’)
lines = fp.readlines()
payload = “”
i = 0;
while i < len(lines):
payload = payload + lines[i]
i = i + 1
while n < options.reps:
send_pkt(payload, False);
n = n + 1
time.sleep(1)
send_pkt(eof=True)
tb.wait() # wait for it to finish
if name == ‘main’:
try:
main()
except KeyboardInterrupt:
pass
##################################################
bbn_802.11b_trasmit_path.py
################################################## from gnuradio import
gr, gru, blks2
from gnuradio import usrp2
from bbn_80211b_pkt import *
#
/////////////////////////////////////////////////////////////////////////////
# transmit path
#
/////////////////////////////////////////////////////////////////////////////
class bbn_80211b_transmit_path(gr.hier_block2):
def init(self, interp, spb, use_barker): #def
init(self, subdev_spec, interp, spb, use_barker):
self.normal_gain = 28000
self.u = usrp2.sink_32fc() #self.u = usrp.sink_c()
dac_rate = self.u.dac_rate();
self._spb = spb
self._interp=int(interp)
self.u.set_interp(self._interp) #
self.u.set_interp_rate(self._interp)
# determine the daughterboard subdevice we’re using
#if subdev_spec is None:
#subdev_spec = usrp.pick_tx_subdevice(self.u)
#self.u.set_mux(usrp.determine_tx_mux_value(self.u,
subdev_spec))
#self.subdev = usrp.selected_subdev(self.u, subdev_spec)
#print “Using TX d’board %s” %
(self.subdev.side_and_name(),)
transmitter******
"""self.packet_transmitter = bbn_80211b_mod_pkts(fg,
spb=spb,
alpha=0.5,
gain=self.normal_gain,
use_barker=use_barker)
fg.connect(self.packet_transmitter, self.u)
gr.hier_block.init(self, fg, None, None)
self.set_gain(self.subdev.gain_range()[1]) # set max Tx
gain
self.set_auto_tr(True) # enable Auto Transmit/Receive
switching"“”
self.packet_transmitter = bbn_80211b_mod_pkts(tb,
spb=spb,
alpha=0.5,
gain=self.normal_gain,
use_barker=use_barker)
tb.connect(self.packet_transmitter, self.u)
gr.hier_block.init(self, tb, None, None)
self.set_gain(self.usrp2.gain_range()[1])
self.set_auto_tr(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) # r =
self.u.tune(self.subdev.which(), self.subdev, target_freq)
if r:
# Could use residual_freq in s/w freq translator
return True
return False
def set_gain(self, gain):
self.gain = gain
self.usrp2.set_gain(gain) #self.subdev.set_gain(gain)
#def set_auto_tr(self, enable):
#return self.subdev.set_auto_tr(enable)
def send_pkt(self, payload=‘’, eof=False):
return self.packet_transmitter.send_pkt(payload, eof)
def spb(self):
return self._spb
def interp(self):
return self._interp
