Re: [Discuss-gnuradio] DSP Block with internal variable output / monitor

[CEL]

Wow, that's a pretty old version GNU Radio! Might be worth updating
your Linux distro :)

Anyways, this is strange! 

You don't happen to implement a `check_topology` method, do you?

Best regards,
Marcus

On Wed, 2019-07-24 at 10:55 -0500, Alex Roberts wrote:
> Sure. FYI I'm running 3.7.10....here is the error:
> 
> Traceback (most recent call last):
>   File "/home/user/gnuradio/dvbt_tx_demo.py", line 384, in <module>
>     main()
>   File "/home/user/gnuradio/dvbt_tx_demo.py", line 372, in main
>     tb = top_block_cls()
>   File "/home/user/gnuradio/dvbt_tx_demo.py", line 307, in __init__
>     self.connect((self.custom_reed_solomon_dec_0, 1), 
> (self.qtgui_number_sink_0, 0))    
>   File "/usr/lib/python2.7/dist-packages/gnuradio/gr/hier_block2.py", line 
> 47, in wrapped
>     func(self, src, src_port, dst, dst_port)
>   File "/usr/lib/python2.7/dist-packages/gnuradio/gr/hier_block2.py", line 
> 110, in connect
>     self.primitive_connect(*args)
>   File "/usr/lib/python2.7/dist-packages/gnuradio/gr/runtime_swig.py", line 
> 5331, in primitive_connect
>     return _runtime_swig.top_block_sptr_primitive_connect(self, *args)
> ValueError: port number 1 exceeds max of 0
> 
> I connected the nerrors_corrected output (type int) to a qt number sink. If I 
> make the output optional and don't connect to it, I don't get the error.
> 
> 
> On Wed, Jul 24, 2019 at 10:38 AM Müller, Marcus (CEL) <address@hidden> wrote:
> > Hi Alex!
> > Hm, interesting. Would you happen to have the full verbatim error?
> > 
> > As a complete aside:
> > I know we're not doing any of that consistently in the tree, but
> > especially when handling things like polynomials "packed" into
> > integers, and amounts of bits, I always recommend people explicitly use
> > "unsigned int", or directly go for an explicitly sized integer type,
> > e.g. "uint64_t gfpoly" for their polynomial representations, so that
> > there's no arithmetic surprises – signed integer overflow, for example,
> > is way less well-defined than unsigned.
> > 
> > Best regards,
> > Marcus
> > 
> > On Wed, 2019-07-24 at 10:30 -0500, Alex Roberts wrote:
> > > So I tried re-implementing the gr-dtv Reed Solomon decoder with an 
> > > additional output so I could monitor/output the number of errors 
> > > corrected.
> > > I used gr-modtool, created new block with new name so it wouldn't 
> > > conflict with the existing and made sure to update the markup language 
> > > for the grc block. 
> > > 
> > > I get an error about Number of outputs 1 exceed max 0. I'm not sure why 
> > > that is.
> > > 
> > > Here is my impl declaration with io_signatures.
> > > 
> > > custom_reed_solomon_dec_impl::custom_reed_solomon_dec_impl(int p, int m, 
> > > int gfpoly, int n, int k, int t, int s, int blocks)
> > >       : block("custom_reed_solomon_dec",
> > >           io_signature::make(1, 1, sizeof(unsigned char) * blocks * (n - 
> > > s)),
> > >           io_signature::make2(1, 2, sizeof(unsigned char) * blocks * (k - 
> > > s), sizeof(int) )), // Change to make2 to support outputting 
> > > nerrors_corrected in the general_work() function
> > >       d_n(n), d_k(k), d_s(s), d_blocks(blocks)
> > > {
> > > ...
> > > }
> > > 
> > > 
> > > On Tue, Jul 23, 2019 at 3:44 PM Alex Roberts <address@hidden> wrote:
> > > > Marcus,
> > > > 
> > > > I think what you said makes sense. I was initially thinking I would 
> > > > have a synchronous block with a message port output, but if I can keep 
> > > > it as simple as a sync block with two outputs just with different 
> > > > sizes, then that is where I will start.
> > > > 
> > > > Thanks,
> > > > Alex.
> > > > 
> > > > On Tue, Jul 23, 2019 at 9:16 AM Müller, Marcus (CEL) <address@hidden> 
> > > > wrote:
> > > > > Hi Alex,
> > > > > 
> > > > > to get this straight: on your monitoring output, you get one item of
> > > > > output per item of input? (an input item being a vector, and a
> > > > > monitoring output item being a number)
> > > > > 
> > > > > Then, everything is well: The thing is still a sync block, just one
> > > > > where not all output item sizes are identical, and not all are
> > > > > identical to the input item sizes.
> > > > > 
> > > > > Even if that's not the case, the right way here would be to write a
> > > > > general block with streams, not an asynchronous messaging block, since
> > > > > the monitoring data is "synchronous" to the other data.
> > > > > 
> > > > > Best regards,
> > > > > Marcus
> > > > > 
> > > > > On Tue, 2019-07-23 at 09:10 -0500, Alex Roberts wrote:
> > > > > > I'd like to monitor an internal variable on a DSP block. have not 
> > > > > > made a custom block before but have read through some tutorials. 
> > > > > > 
> > > > > > Since the DSP inputs and outputs are vectors, and the variable is a 
> > > > > > single item whose value is dependent on the processing of the 
> > > > > > vector, the number of outputs does not match the number of inputs. 
> > > > > > The value is updated after each input vector is processed. Does 
> > > > > > this mean I should use the message port to asynchronously output 
> > > > > > the variable, or can I simply add another port and output the value 
> > > > > > as say a float or integer that is synchronously updated with the 
> > > > > > block?
> > > > > > 
> > > > > > For example, in a Reed-Solomon implementation, how could I add an 
> > > > > > output to monitor the number of errors corrected?
> > > > > > _______________________________________________
> > > > > > Discuss-gnuradio mailing list
> > > > > > address@hidden
> > > > > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> > > 
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> 
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