[Discuss-gnuradio] Slow control external hardware

[Daniele Nicolodi]

Hello,

I need to control a RF synthesizer from within a GNURadio flowchart
updating some parameters on the base of some measurements obtained from
processing data collected by an USRP.

The synthesizer is connected through a RS232 serial port, thus is quite
slow, but the bandwidth of the control is also very small, < 1Hz. One of
the parameters that needs to be controlled is the output power, and it
can be adjusted only in discrete steps of 0.01 dB, therefore I need to
correctly take care of the discretization.

What is the best strategy to do that? Should I simply implement a sink
block? Would be better to implement the discretization in a sink block
that then sends messages to another block that handles the communication
with the synthesizer?

As far as my experimentation goes, there are no blocks using messages in
the standard GNURadio distribution (version 3.7.2), therefore I don't
really have examples of use cases for it.

Thanks. Cheers,
Daniele