I've developed a small interface board for the HAMWARe controller AT-502, AT-515 and AT-651U. This interface boards supports RS232 and CI-V communications and can be directly mounted into the controller chassis.
There are two DB9 connectors for RS-232 communication and two 3,5mm phone jacks for CI-V communications. You can find the circuit diagram in the user manual.
I can provide parts as well as the PCB at cost price. Details please check here.