@DV52 I retrofitted my RVC and it took me couple weeks before finding the right one. The thing is that I had this modification in mind and I knew that I would need RVC HIGH, not RVC LOW, to make this work. If you look closely: my car is stationary, gearbox is in PARKED at all times. I just use the Parktronic button.
RVC LOW is controlled as you said: camera, mechanism and MIB use trigger signal from the reverse light (camera and mechanism directly, MIB via CAN-BUS message from BCM). As soon as the signal is gone, camera will shut down, mechanism will go to 10s timeout and close, MIB will go back to previous screen.
However, RVC HIGH is controlled differently, which gives me more options.
First of all camera is not triggered by reverse gear. It's triggered by "camera image is needed" message send via CAN-BUS from BCM, from Parktronic, from ABS, or from MIB. This message can be send when:
- reverse gear is selected,
- Parktronic button is pressed,
- car is rolling backwards,
- camera button on MIB GUI is pressed (that's actually for 360 AreaView and maybe for cameras in trucks with different parameterization - not sure 100%).
The mechanism is not controlled by the same signal as the camera. Mechanism is controlled directly from the camera itself when the camera needs it. It's the camera module that opens the mechanism when it's needed. You can open the mechanism with module 0x6C output test "emblem motor (0998)".
Now, turning the camera off. RVC LOW image will disappear as soon as you disengage reverse gear.
However, RVC HIGH will stay active until you reach ~15km/h. That's true even if you are moving forward. Something that is not possible with RVC LOW. This means that will have the video feed active while moving forward.
Now the big thing. Custom control module that has one job - power the relay based on the logic from the car.
I need to tap into couple signals:
- reverse gear status (DSG indicators will give me this),
- parktronic status (orange indicator in button will give me that).
If parktronic indicator is on, I know that the RVC is active (more or less, there's one exception but I will ignore it now).
If parktronic is on and reverse is not engaged, I know that I need to power the relay.
I mentioned a custom button to override this logic. Here's how it will work.
If custom button is pressed, control module needs check if parktronic is active.
If it is active, it just needs to toggle the relay.
If it is not active, it needs to press the Parktronic button for me (override the OEM button) and power the relay.