Definitely CAN. All new engines (Rotax, ULP etc) use CAN. Many EFIS’es use CAN to communicate with boxes (they have to, or they won’t get any engine data).
I’ve added CAN 
So now I have CAN, RS232, RS422, RS485 and ARINC429 on the same box.
When will you test it ?
Which ADSBIN/FLARM box will you choose as input ?
The product this is being done for is nothing to do with aviation.
Once it is done, I will look for opportunities for converters for various purposes
