Originally Posted by tejesh83

what scan converter did you use?

Originally Posted by met152

thanks Zax,
Yeah, it was a decent amount of work. First I had to build a small module that would allow me to switch between the stock function and the usb controller. This required some guesswork as to the right size connectors and cables to order from digikey.

The touchscreen uses a 4-wire resistive panel that goes into the touchscreen display board (board behind the lcd screen). This goes out on a flat flexible cable (FFC). My module takes in that signal in through a FFC conector, and passes it through the NC contacts of a 4PDT relay, and then back out to the stock display board. The NO contacts of the board are fed into a USB touchscreen controller. When the relay is de-energized, the screen acts like it does from the factory. When the relay is energized, the touchscreen coordinates are only sent to the USB controller.

The only physical modification that I made to the stock hardware, was some cutting of the metal cover on the back of the display unit. This allowed the FFC from the touchscreen to reach my module. I can remove this module and return everything to stock, of course minus the cutting. It would be possible to do this without cutting, but you'd need to extend the flat cable to reach the module (I didn't have the ability to do this at the time and I didn't mind cutting)
This shows where I cut.


To answer your other question zax, I am going to get video on the screen using a scan converter that will convert VGA to RGBs at the 15kHz frequency required by the navi lcd. I will be doing this using a piece of hardware made by Communications Specialists (I think that's their name). It's the "Scan DO 800"
This conversion should give me the best possible display on the stock screen. It won't be great due to the low resolution of the lcd, but it will be better than using the RCA input on the Dom's unit.

I don't have the PC that I'll be using yet, but it will probably be based on a VIA mini-itx mainboard in an enclosure in the trunk. I already have a usb gps receiver to use with Iguidance or some other pc based navigation software. I might look into feeding data from the Acura gps receiver, but I'm not sure how difficult this would be.

Here are all the pictures I took. Looking back, I should have taken more.

















Please let me know if you have any questions whatsoever. If anyone is interested in doing this themself, please let me know if I can help. I can send you a list of all the parts (and the $$ of all) that you'll need.
I thought about making a module to sell, but I doubt many would be comfortable doing this. And if they were comfortable doing this, then they'd be able to make their own just as easy.
You can email me at: mike at mtatko dot com

Originally Posted by KN_TL

If you want to maintain the factory nav system then this is the only way to go. I am going to be doing this eventually pretty much like the OP did. The only thing you have to be concerned with is add resistance to the circuit since it is a 4 wire resistive touch screen.

Originally Posted by Roger555

Factory Nav I dont care about because google nav is 5 million time better. I do still need the trip computer and the integration wit the stereo though.

Originally Posted by dwb993

I am actually very close to doing this. I have the CarPC powered up and installed in the trunk using a BT Logitech keyboard for control. I have made the relay unit following Roger555's great schematic. Its all just waiting for a nice weekend with no kids to pull the dash apart and install it.
My question is about the "add resistance to the circuit since it is a 4 wire resistive touch screen." Can someone elaborate? I have seen nothing about this in either Met152 or wrxyboy's threads on this interface.

Originally Posted by csmeance

You could instead do what I suggested a while back and take out the factory LCD screen (only the LCD) and put in a much better high res display. You can buy a converter to convert the navi signal into a regular RCA video ouput and plug that into your new screen and use the joystick to control the navi/trip computer/audio. No loss of any functions either!




I used a touch-screen controller with a relay just like met152 did and there wasn't an issue for a while until the controllers kept on breaking. I think KN_TL meant there reverse and meant to say that you don't ADD resistance to the system otherwise the controller won't work

Originally Posted by Roger555

Also does the relay your using have a protection diode installed? Some relays come with them inside but some do not. Without a diode going across from (-) to (+) terminal of the relay each time the relay is activated/deactivated there is a huge voltage spike that will damage sensitive components.