Tapping into touchscreen signal.

[scottb721]

Anyone seen any threads relating to picking off the touchscreen output for controlling other devices ?

My concept is to use the factory nav's touchscreen with a USB touchscreen kit that can then control a 2nd device like a car PC, smart phone etc.
Only issue I can think of is that in all other modes other than Aux Video the 2nd device would still be responding to the touchscreen interaction.

A 2nd touchscreen overlay is no good as I presume it would prevent the normal touchscreen from working.

Just thinking out aloud. Thanks

[mynameisdaniel]

Did think about doing this myself, although as I didn't already have the screen it wasn't worthwhile and worked out better to just mount a screen there. If you look into how the touch screens work there's basically a panel which is connected to a circuit board using a (usually) 4 or 5 pin ribbon cable. If you were to connect this to a suitable USB controller you could intercept all the signals and use it with your computer instead.

The problem is you'd need to dismantle the screen to find out what sort of connector it uses, then either extend the ribbon outside of the screen or mount a USB controller inside the screen (if it fits) and run the USB cable outside. Doing so you'd remove all touch screen capability of the sat nav itself (making it useless?). But theoretically it is possible.... A decent touch screen with AV, HDMI and VGA in doesn't cost much over $200 though...

[scottb721]

Theoretically I'd pick off the X+ X- Y+ Y- signals off the factory screen rather than using it solely for a USB controller.
I like my factory nav, and the other stuff it does, so wouldn't give that up for some hair brain idea.

[mynameisdaniel]

Theoretically I'd pick off the X+ X- Y+ Y- signals off the factory screen rather than using it solely for a USB controller.
I like my factory nav, and the other stuff it does, so wouldn't give that up for some hair brain idea.

Ahh I see what you're trying to do. If you can do that it should be pretty easy. Just have like a disable button or something on the computer software for the screen, or a keyboard combination that activates/disables the touch screen input to the computer.

What happens if you touch the screen while in AV mode? Do you get menus popping up and stuff? As that would kind of foil the idea

[scottb721]

When the screen is in Video In mode touching it doesn't bring up any car or nav menus.

I've got the screen's workshop manual so has only added to my what-if thinking that has plagued me my life. Mind you that thinking gave me aftermarket cruise operated by my washer stalk and having my phone connected to the stacker port on a Pioneer stereo in my old Impreza

[scottb721]

It occurred to me yesterday that I could try other input methods for the phone. Namely a mini trackball or Logitech Wireless Touchpad which is only $30 atm.

To test usability of a mouse type device I gave a standard mouse a try in car and was very satisfied with the results.
Some pics here http://imgur.com/a/ksmF8#0 show the mouse cursor on screen.

[bigBADbenny]

What's the setup there? Is the phone displayed on the factory nav screen via the aux video input?

[scottb721]

Yep, video in on the factory sat nav and audio going to the McIntosh.