[Hamlib-developer] Adding a backend to hamlib

[<man...@sa...>]

Hi,

I'm looking into implementing a backend for Hamlib to interface with  
Primetec's Primesat Controller, and I have a couple of questions about  
the integration of the controller with Hamlib that I couldn't find  
answers for in the docs. Hope that this mailing list is the correct  
place to ask for help.

This controller is a simple hardware interface module that allows the  
user to control a radio and/or a rotator via a serial connection. It  
supports Yaesu G5400 and G5500 rotors, and ICOM IC821, IC910, and  
IC706, Kenwood TS790, TS2000, and TS850, and Yaesu FT736, FT847, and  
FT857/897 radios.

Currently, I have the following questions:

- I understand that Hamlib already has backends for these rigs when  
connected to the computer using their native interfaces. Still, would  
the maintainers accept merging a backend for this interface device?

- The controller receives radio and rotator commands through a single  
serial port. From my understanding of Hamlib's architecture and source  
code, this means that it is not possible to use both rigctl and rotctl  
at the same time as the first to be launched would lock the serial  
port and stop the other from issuing commands to the module. It this  
correct? Or is there another way of sending both types of commands via  
the same serial port?

- When filling out the rig_caps or rot_caps structure, what is the  
correct way to fill the members corresponding to unsupported  
capabilities? Should the member still point to a function returning an  
error? RIG_ENAVAIL? Or should these members point to NULL?

- The controller is a very simple device with no internal state, and  
it does not send any data out. It only receives messages via the  
serial port. The only confirmation that the commands are successfully  
being received is through a display on the front panel of the device.  
Do you recommend that I implement some get functions using rig_state  
or priv_data? Or should I implement only the set functions since that  
is the functionality the hardware actually supports?

Best regards,

Manuel Santos