Re: [Discuss-gnuradio] Passing the payload to the application level

[Michael Ford]

Actually, I just realized - that's the only copy of gmsk2_pkt.py that exists for me. I'm not in the lab right now, but I remember doing searches for that file and having it only show up in the root directory. Is that a problem?

On 9/21/06, Michael Ford <address@hidden> wrote:

Eric,

I've been editing /usr/local/lib/python2.4/site-packages/gnuradio/blksimpl/gmsk2_pkt.py

From what I'm reading, it sounds like this is incorrect. I'm going to edit the file that you suggest before I explore your other options.

-Michael Ford-

On 9/21/06, Eric Blossom < address@hidden> wrote:

On Thu, Sep 21, 2006 at 01:05:58AM -0500, Michael Ford wrote:
> Packet reception is great, no problems there at all.
>
> The prblem is that since the rx_callback function is called within the
> _queue_watcher_thread class, I figured I could return the payload to
> benchmark_gmsk2_tx.py from there (as opposed to simply printing the
> payload). However, when I create a member variable in the
> _queue_watcher_thread class called self.thepayload, and return the payload
> from the rx_callback function into said member variable, and then try to
> pass it back to the app layer, I get errors saying that the
> _queue_watcher_thread class has no such member. Also, when I try to directly
> print the payload obtained from the calls
>
> def run(self):
>        while self.keep_running:
>            msg = self.rcvd_pktq.delete_head()
>            ok, payload = packet_utils.unmake_packet( msg.to_string())
>            print payload                 #added by me
>            if self.callback:
>               self.callback(ok, payload)
>
> nothing happens.

Perhaps you're neglecting to do a "make install" after editing in gnuradio-core?
Are you editing in the build tree?  That is
.../gnuradio-core/src/python/gnuradio/blksimpl/gmsk2_pkt.py ?

That would be correct, but you'll need to be sure to perform a

$ make install

To get it put in the place that it'll be seen when you run the
example.


FWIW, when I'm messing with this and the stuff in gnuradio-examples at
the same time, I usually have my current directory in
gnuradio-examples/python/gmsk2, but after I edit something in
gnuradio-core/.../blksimpl I execute

  $ (cd <path-to-top>/gnuradio-core/src/python; make install)

Then run my test code

  $ ./benchmark_rx.py ...

> But perhaps the most baffling thing is that no matter what I do to the
> _queue_watcher_thread class, even totally comment it out, rx_callback still
> runs. Also, printing the payload from within the rx_callback function works,
> and that is the only place it works. I am under the impression that
> rx_callback is passed down to the _queue_watcher_thread class and is called
> from there. Why would it still output to the screen if I comment out the
> class?
>
>
> I am basically trying to use the contents of the payload as a conditional,
> but I can't pass the payload back up to benchmark_gmsk_rx.py to save my
> life.
>
> Sorry if I'm not clear.

No, this is clear.  Please let me know if this solved the problem of
not seeing your changes.


However, I still don't understand why you want to mess with the code
in gmsk2_pkt.py.  It fires the callback which is provided in
benchmark_gmsk2_rx.  You have complete control of what happens from
there.

E.g., in benchmark_gmsk2_rx, instead of passing the existing callback
like this:

    # build the graph
    fg = my_graph(blks.gmsk2_demod,
                  options.rx_subdev_spec, options.bitrate ,
                  options.decim, options.spb, rx_callback,
                  options, demod_kwargs)


You could either redefine the existing callback, or compose the
existing callback with a function that performs the conditional.
E.g.,

def filter_based_on_payload(callback):
    def wrapped_callback(ok, payload):
        if my_conditional(ok, payload):         # whatever you want here
            callback(ok, payload)               # fire callback passed in
         else:
           pass # ignore the payload, or whatever

    return wrapped_callback          # return the closure


Then,

    # build the graph
    fg = my_graph(blks.gmsk2_demod ,
                  options.rx_subdev_spec, options.bitrate,
                  options.decim, options.spb, filter_based_on_callback(rx_callback),
                  options, demod_kwargs)


Eric