The conversion of all the example code and blks code on the trunk to the new
3.1 flow graph code is nearly complete.
This is being done in the jcorgan/t162 developer branch if you want to take a
look.
Once this is merged into the trunk, you'll be able to restore GRC functionality.
Sent via BlackBerry by AT&T
-----Original Message-----
From: Josh Blum <[EMAIL PROTECTED]>
Date: Fri, 14 Sep 2007 20:34:40
To:Dev Ramudit <[EMAIL PROTECTED]>
Cc:discuss-gnuradio@gnu.org
Subject: Re: [Discuss-gnuradio] OFDM GRC block attempt
In short, the GRC code for the packet modulator was no good after the
"incompatible trunk check in". So, I just deleted the packet mod/demod
code in GRC.
To restore the functionality of the packet mod/demod (in grc), i would
have to cannibalize the current blks.pkt code. I will be glad to do
this, especially if someone is using the blocks.
The only thing about the packet mod/demod blocks is that they are
implemented poorly. For example, to implement a packet modulation block,
you have to sample the gnuradio stream with a message sink and a thread,
the error coding/packetizing is done in python with packet utils, and
then the data is pushed back into the gnuradio stream with a message
source. Not too efficient. Any suggestions before I go ahead with the
message source/sink idea?
Anyway, it would be great to get ofdm working with GRC.
-Josh
Dev Ramudit wrote:
> Hello all,
>
> I'm trying to write an OFDM mod/demod for the gnuradio companion and
> I'm running into a problem. I'm following the (now deprecated?) packet
> modulator code that was in GRC very closely. I have an OFDMDemod block
> which creates the following class when its used:
>
> ---
>
> class OFDMDemodHelper(gr.hier_block2):
> """Forward data from ofdm demod to the gr data stream."""
> def __init__(self, item_size, options):
> #create hier block
> gr.hier_block2.__init__(
> self, 'ofdm_demod',
> gr.io_signature(1, 1, Complex().get_num_bytes()),
> gr.io_signature(1, 1, item_size)
> )
> #the message source (handles the output data stream)
> msg_source = gr.message_source(item_size, DEFAULT_QUEUE_LIMIT)
> msgq = msg_source.msgq()
> def callback(ok, payload):
> if ok: msgq.insert_tail(gr.message_from_string(payload,
> 0, item_size,
> len(payload)/item_size))
> ofdm_demod = blks.ofdm_demod(
> fg=self,
> options=options,
> callback=callback,
> )
> #connections
> self.connect(msg_source, self)
> self.connect(self, ofdm_demod.head)
>
> ---
>
> This is basically the same as the old packet demod code, with a few
> small changes for OFDM. Unfortunately, I get the following error:
>
> ---
>
> File "/home/dramudit/work/gnuradio/grc/src/SignalBlockDefs/Packet.py",
> line 337, in __init__
> callback=callback,
> File
> "/usr/local/lib/python2.4/site-packages/gnuradio/blksimpl/ofdm.py", line
> 218, in __init__
> options.log)
> File
> "/usr/local/lib/python2.4/site-packages/gnuradio/blksimpl/ofdm_receiver.py",
> line 56, in __init__
> self.fg.connect(self.chan_filt, self.ofdm_sync)
> File
> "/usr/local/lib/python2.4/site-packages/gnuradio/gr/hier_block2.py",
> line 46, in connect
> self._connect(points[i-1], points[i])
> File
> "/usr/local/lib/python2.4/site-packages/gnuradio/gr/hier_block2.py",
> line 50, in _connect
> (dst_block, dst_port) = self._coerce_endpoint(dst)
> File
> "/usr/local/lib/python2.4/site-packages/gnuradio/gr/hier_block2.py",
> line 61, in _coerce_endpoint
> raise ValueError("unable to coerce endpoint")
> ValueError: unable to coerce endpoint
>
> ---
>
> Any suggestions as far as fixing this error, or another approach?
>
> Thanks,
> Dev
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> Discuss-gnuradio@gnu.org
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
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