[Discuss-gnuradio] GRC - wrapping a GNU Radio block that uses message_sink

[Richard Clarke]

Hi,

I have a 3rd party GNU Radio block of signal processing code that I would like to wrap for use within GRC. This block uses a message sink (i.e a pointer to a gnu radio message queue is passed into the block which appears to then utilise the queue for inserting 'send frequency correction' values to another process. I have read that GRC currently supports users creating block wrappers for blocks with message queue IO. In the xml file I write, is the message queue a second 'sink', i.e in addition to the standard float stream of samples it outputs, or should it be handled in the parameter section of the xml code? I've searched all existing standard blocks and haven't found an example to work from. Does anyone have an example they could share?

Or have I also got my source and sink perspectives confused and this block should instead be a msg source? Even so, my questions above remain.

Many thanks.

Cheers
Richard