This is an ongoing project I'm working on which started as a circuit that I decided was necessary to be able to neatly interface the nNovia QC120 A2D2 recorder to a Sony DXC-325P camera with CA-325P studio back.
This interface deals with translating VTR start/stop signals from the camera into GPI signals to pause and resume the recorder when it is in record mode.
In addition to the device control, there will also be XLR Balanced line input to be converted to unbalanced line level.
There is also the possibility of getting it to communicate with the nNovia RS-422 port and using this protocol to control the device.
I'm still working on the final design. I have built the PIC 16f872 based circuit that controlls the nNovia via the GPI control lines and this seems to work very well.
The next step with the PIC interface is to try controlling the RS232 port on the nNovia to start and stop the deck and get its status.
I will be prototyping the Preamp shortly. I have a plan to use the A2D interfaces on the PIC to drive an LED PPM or VU meter on the front panel of the case.
Here's the schematic of the current prototype.