Need help detecting on/off state for indash display, and switch to touch cont.
I have been searching all over the place (almost reached the end of ) and I still can not find a way to do the following. Please keep in mind that the extent of my electronics knowledge only goes as far as tying to wires together.
I have a 2006 Subaru with navigation, rear seat DVD, and in dash Multi-function-display (MFD) that can accept a reverse camera input. I have managed to install a carpc under the driver side seat and have the audio/video integrate with the factory MFD and stereo through the rear seat DVD/AUX lines (I have a multi-input==>multi-output AV switch and have the rear seat DVD, carpc, and AUX plug as input, and have the rear seat DVD and front MFD as outputs.) Additionally, I have attached an additional touch screen controller and tapped it to the touch screen of the factory MFD (switching from factory to new touch controller though a 4-point magnetic relay). In order to display audio/video from carpc, I switch to the right input on the AV switch, and then click the "Audio" button of the factory system twice to activate video, and click on "Rear ent/AUX" bottom on factory stereo to activate sound from carpc. then I switch toggle the touch screen controller to activate the one attached to the carpc, and all is ready.
When I want to switch from NAV touch controller (factory) to carpc touch controller (new), I have to flip a switch one way or the other. I was wondering if it is at all possible to have something detect whether the display is showing the input from the PC/NAV and accordingly have this something switch to the appropriate touch screen controller? There must be something that can sense changes in the RCA line carrying the video signal and detect whether the monitor is switch to PC or NAV.
Many thanks and advance
If you are using a mechanical switch, you can get a DPDT switch. One side will switch the video signal and the other side will switch the LED as your indicator. A bi-color LED would be interesting.