plz help

[ashishbathini]

Guys I need your help ....
In this code I have to change the value of the frequency ...
the code takes the values of frequency and bit rate as inputs but i have to enter the value of freq manually ...
Plz help as i'm unable to understand this high level code


PROGRAM A

#!/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.
#

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, time, struct, sys

# from current dir
from transmit_path import transmit_path
import fusb_options

#import os
#print os.getpid()
#raw_input('Attach and press enter')


class my_graph(gr.flow_graph):
def __init__(self, modulator_class, options):
gr.flow_graph.__init__(self)
self.txpath = transmit_path(self, modulator_class, options)


# /////////////////////////////////////////////////////////////////////////////
# main
# /////////////////////////////////////////////////////////////////////////////

def main():

def send_pkt(payload='', eof=False):
return fg.txpath.send_pkt(payload, eof)

def rx_callback(ok, payload):
print "ok = %r, payload = '%s'" % (ok, payload)

mods = modulation_utils.type_1_mods()

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("-s", "--size", type="eng_float", default=1500,
help="set packet size [default=%default]")
parser.add_option("-M", "--megabytes", type="eng_float", default=1.0,
help="set megabytes to transmit [default=%default]")
parser.add_option("","--discontinuous", action="store_true", default=False,
help="enable discontinous transmission (bursts of 5 packets)")

transmit_path.add_options(parser, expert_grp)

for mod in mods.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.exit(1)

if 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)

# build the graph
fg = my_graph(mods[options.modulation], options)

r = gr.enable_realtime_scheduling()
if r != gr.RT_OK:
print "Warning: failed to enable realtime scheduling"

fg.start() # start flow graph


# generate and send packets
nbytes = int(1e6 * options.megabytes)
n = 0
pktno = 0
pkt_size = int(options.size)

while n < nbytes:
send_pkt(struct.pack('!H', pktno) + (pkt_size - 2) * chr(pktno & 0xff))
n += pkt_size
sys.stderr.write('.')
if options.discontinuous and pktno % 5 == 4:
time.sleep(1)
pktno += 1

send_pkt(eof=True)
fg.wait() # wait for it to finish

if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
pass