Problems in locking and unlocking the flow-graph

GNU Radio
1

hi,
I am designing a transmitter which needs to transmit two different types
,
tone (of 1k frequency) and data (2k & 3k frequency).Both of them take
user
input, does processing and produce output on sound card of the laptop
(am
not using usrp).

I have implemented this all in a single flow graph and used lock and
unlock
to reconfigure the flow-graph.But it gets to a hanging state and looks
like
it is waiting for something in queue. I did try to use gr.message(1)
before
locking , which locked and unlocked the flow-graph but the problem is
that
after using gr.message(1), self.src does not get further data from the
queue and without using it, it is stucked.

plz find some way out for me to transmit tone and data as required.

class tx_graph(gr.top_block):

def __init__(self):
    gr.top_block.__init__(self)


    self.src = gr.message_source(gr.sizeof_char, msgq_limit)

#
#  tone_blocks                            // tone processing blocks

here
#

#
#  data_blocks                            // data processing blocks

here
#

self.sink = audio.sink(audio_rate,"plughw:0,0")
self.connect(self.src,//data_blocks//,self.sink)    # assume that

initially data is being transmitted

def tone_transmit(self):
self.lock()
self.disconnect(self.src,//data_blocks//,self.sink)
self.connect(self.src,//tone_blocks//,self.sink)
self.unlock()

def main():

fg=tx_graph()
fg.start()

while True :
    // assume first only data is being tranmitted


        try:




        message = raw_input("Enter a message to transmit (Ctrl-D to

exit): ")
msg64 = base64.standard_b64encode(message)
print “Encoding message= %s to base64= %s” %
(message,msg64)

                payload =

clock_sync+sync+encode_6b_8b(msg64)+stop_sync
pkt = struct.pack(‘%iB’ % (len(payload)),*payload)

                msg = gr.message_from_string(pkt)

                fg.src.msgq().insert_tail(msg)

        except EOFError:
            print "\nExiting."
            fg.src.msgq().insert_tail(gr.message(1))
            fg.wait()

// assume now only tone is being transmitted



        try:
        fg.tone_transmit()
                message = raw_input(" transmit a 5ms tone (Ctrl-D to

exit): ")
pkt = struct.pack(‘B’, 0xff)

                msg = gr.message_from_string(pkt)
                fg.src.msgq().insert_tail(msg)

        except EOFError:
            print "\nExiting."
            fg.src.msgq().insert_tail(gr.message(1))
            fg.wait()

if name == ‘main’: # main python entry here
try:
main()
except KeyboardInterrupt:
pass

–
Niaz A.

We are always more anxious to be distinguished for a talent which we do
not
possess, than to be praised for the fifteen which we do possess* :
Mark
Twain http://thinkexist.com/quotes/mark_twain/*