Re: [Discuss-gnuradio] IO types in GRC xml files

[Moritz Luca Schmid]

Hi Vipin,

> My application requires a custom GRC block. Everything seems to work 
> Ok except in the last stage where we are supposed to create the xml 
> file so that the block is visible in the GRC gui.
>
> When I instantiate the custom block in GRC GUI and double click on the 
> block, I see several errors such as "Type Complex is not a possible 
> type" in the dialog box that pops up.
>
> I thought Complex is one of the supported types in gnu radio. Why does 
> that warning show up?

you are not wrong, complex is a supported type in gr.

> Here is the small excerpt of the xml code:
>
>   <!-- Make one 'source' node per input. Sub-nodes:
>        * name (an identifier for the GUI)
>        * type
>        * vlen
>        * optional (set to 1 for optional inputs) -->
>   <source>
>     <name>EstimatedCh</name>
>     <type>Complex</type>
>   </source>

But be careful: XML files are case sensitive, so you should write 
'complex' instead of 'Complex'.

If you are not that familiar with XML files, you can let gr_modtool 
makexml do some work for you.

And if you are not sure about the XML syntax, simply 'use the source' 
and search for an existing gr block's xml file with the same 
parameter/input/output type and check out its use.


Regards
Luca