Re: [Discuss-gnuradio] Updating old 802.15.4 code to latest release

[Dimitris Symeonidis]

Hi Leslie,

I have encountered the same problem in my RDS code
(https://www.cgran.org/wiki/RDS)
The error comes up because I have a top_block that creates a msg_queue
and passes it (as an argument) to a hier_block2.
This hier_block2 then outputs to the queue. I am receiving the same
error message (try running rds_scope_pll_test.py under src/python,
which calls rds_rx.py).
I haven't yet had the time to look into this, because I resolved it by
integrating the hier_block2 functionality inside the top_block (look
at usrp_rds_scope_pll.py)

If you do find the source of the problem, I would appreciate it if you
pass it on to me

Kind regards, and good luck


Dimitris Symeonidis
"If you think you're too small to make a difference, try sleeping with
a mosquito!" - Amnesty International



On Wed, Oct 29, 2008 at 03:34, Leslie Choong <address@hidden> wrote:
> Hi everyone,
> I'm currently updating Thomas Schmid's old 802.15.4 demodulation code.
> It has been tested and works with at least revision 7596 of the
> gnuradio trunk. I've been trying to update the code to work with the
> latest release of Gnuradio (3.1). I've looked at examples converting
> from hier_block to hier_block2 and flow_graph to top_block. I've
> implemented those changes but still run into this error:
>
> python: /usr/include/boost/shared_ptr.hpp:375: T*
> boost::shared_ptr<T>::operator->() const [with T = gr_basic_block]:
> Assertion `px != 0' failed.
>
> Searches for this error on the list did not turn up much. I was
> wondering if there was anything else that I missed. I've been banging
> my head on the wall about this trying to figure out a fix. I jumped
> into gdb and found that the code was crashing when trying to flatten
> the flow_graph. I turned on debugging messages for
> gr_hier_block2_detail.cc and here is the result of that:
>
> connecting: ieee802_15_4_demod(3):0 -> sos_packet_sink(8):0
> connect: src is hierarchical, setting parent to 0x89e3d00
> connecting: usrp1_source_c(1):0 -> pwr_squelch_cc(9):0
> connecting: pwr_squelch_cc(9):0 -> ieee802_15_4_demod_pkts(2):0
> connect: dst is hierarchical, setting parent to 0x88bc270
> start: entered
> flattening top_block
> Flattening edge usrp1_source_c(1):0->pwr_squelch_cc(9):0
> Flattening edge pwr_squelch_cc(9):0->ieee802_15_4_demod_pkts(2):0
> Resolving endpoint ieee802_15_4_demod_pkts(2):0 as an input, recursing
> Resolving port 0 as an input of ieee802_15_4_demod_pkts
> python: /usr/include/boost/shared_ptr.hpp:375: T*
> boost::shared_ptr<T>::operator->() const [with T = gr_basic_block]:
> Assertion `px != 0' failed.
> Aborted
>
> I have attached a patch for anyone who wants to look further. If you'd
> like to see all the code you can follow these steps to try it out
> yourself:
> svn checkout svn://acert.ir.bbn.com/svn/gr-ucla
> cd gr-ucla/trunk
> (copy changes.diff to this directory)
> patch -p0 -i changes.diff
>
> Then build it all:
> ./bootstrap && ./configure && make
> sudo make install
>
> then:
> cd src/examples
> ./cc2420_rxtest.py
>
>
> If you have any comments or leads on something else that I should look
> into I would really appreciate hearing it. Thanks for all your help!
> -Leslie Choong
>
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