I have a T43 display connected to RGB and T sockets through the 37-pin d-sub connector.
I plan to connect display when its needed but the rest time the display will not be connected while operating.
I want to disable all display functions in case when display is not connected so I need a way to determine is a display connected or not (once time, on board startup only).
Is it possible to do this without additional wiring, I mean using only the RGBT sockets?
look on the schematic and see what you can use. I note that TCH_XL and TCH_YU (pins 5 and 4) are connected to ground via 10K resistors. Also SHDN is connected to 3.3v via a 1.5K resistor on the G socket.