Problems with the examples

GNU Radio
1

Hello all!

I’m working on OFDM synchronization for GNURadio and we need a file to
simulate the OFDM. I thought it would be a good way use the
audio_to_file.py of the examples, but it doesn´t work. I speak to the
microphone but when I run audio_play.py nothing is listened. I think the
problem might be because when I push ENTER the execution of these
examples should finish and it doesn’t, it continue running until I kill
the process (ctrl+c). It occurs with all the examples and I don’t know
what can be the problem because I’ve checked the code on the website and
it is the same… The lines which should do it are:

if name == ‘main’:
try:
my_top_block().run()
except KeyboardInterrupt:
pass

I think that it is ok and with these lines the program should stop by
pushing ENTER but it doesn’t. The microphone problem must be other one
but i`m starting to suspect that the file doesn’t record fine because of
this mistake. Can be useful for you that when I run audio_to_play.py it
finishes when the file finishes(last a little of time) although it
doesn’t sound anything, and it doesn’t stop if pushing ENTER.

I know these are very elemental doubts and problems but are stopping us
of going on with our work and we are not able to solve it.

Thank you very much

2

On 2/11/08, Jose Emilio Gervilla R. [email protected] wrote:

if name == ‘main’:
try:
my_top_block().run()
except KeyboardInterrupt:
pass

I think that it is ok and with these lines the program should stop by
pushing ENTER but it doesn’t.

In Python, a KeyboardInterrupt is caused by Ctrl-C, not by hitting any
key. The above code snippet is acting as it should.

If you want the flowgraph to end with an Enter key:

if name == ‘main’:
tb.start()
raw_input(“Press Enter to stop.”)
tb.stop()
tb.wait()

–
Johnathan C.
Corgan Enterprises LLC
http://corganenterprises.com/

3

So, my problem must be with the microphone used in the notebook. I use
the integrated microphone and it doesn’t record anything, might be I
should use the command -I to let the program know that the source is the
microphone, but how is it called in Linux? I mean, the line to call the
program would be:

./audio_to_file.py -I (here how do I define the microphone in linux??)
test.dat

Might be also linux configuration for the microphone, can anyone tell me
what is the right one?

Thank you very much! > Date: Mon, 11 Feb 2008 10:16:47 -0800> From:
[email protected]> To: [email protected]> Subject: Re:
[Discuss-gnuradio] Problems with the examples> CC:
[email protected]> > On 2/11/08, Jose Emilio Gervilla R.
[email protected] wrote:> > > if name == ‘main’:> > try:> >
my_top_block().run()> > except KeyboardInterrupt:> > pass> >> > I think
that it is ok and with these lines the program should stop by> > pushing
ENTER but it doesn’t.> > In Python, a KeyboardInterrupt is caused by
Ctrl-C, not by hitting any> key. The above code snippet is acting as it
should.> > If you want the flowgraph to end with an Enter key:> > if
name == ‘main’:> tb.start()> raw_input(“Press Enter to stop.”)>
tb.stop()> tb.wait()> > – > Johnathan C.> Corgan Enterprises LLC>
http://corganenterprises.com/

4

To clarify, there was one missing line. Here is the snippet again,
with comments:

if name == ‘main’: # Execute if script invoked
as program
tb = my_top_block() # Create an instance
of a custom top block
tb.start() # Start
the flowgraph running in background thread
raw_input(“Press Enter to stop.”) # Wait for user to hit enter
in foreground thread
tb.stop() # Tell
flowgraph to gracefully exit
tb.wait() # Wait for
it to do so

–
Johnathan C.
Corgan Enterprises LLC
http://corganenterprises.com/