Touchscreen + computer?

There's a thread under the Main forum called "Screen saver covers??" that discusses these.

Lou

 

Riskable,

I am interested in this too - wondering if there is a way to connect with the touchscreen digitally - for example LVDS coming off of a VIA motherboard. Even if that is possible - the trick might be lack of a driver.

Does anyone know if the TechToyota website provides detail information about the innards of the LCD unit?

Mark

 

That would be difficult. It would certainly involve a lot more work then just getting an aux video signal onto the screen.

The first trick is figuring out how the screen tells the dash board computer what was pressed. One would hope this is a simply x/y value that is then calculated by the computer.

Next problem is intercepting that signal, which involves figuring out *how* the signal is transmitted in the first place. It would certainly be nice if we could just splice in a USB cable and then treat it as a standard touch screen; but I doubt Toyota has off the shelf wiring between the screen and the dash board computer. :?

I suppose anything is possible, but it is just how far you are willing to go to make it happen. Unless you are willing to snip wires and track down the signals I don't think we will be seeing this level of integration anytime soon.

Riskable, where are you reading about the ability to interface a computer with a composite connection? I've not found any specs on putting something like that in... and am unwilling to crack open my intrument panel to figure out how. Do you know of a site that is pointing out how to go about this?

 

I know about the Computer -> Video part... I was checking in about the Video -> Prius part.

Your original post made it sound like you were already aware of how to install a component video input into the Prius. That's the part I'm trying to figure out this point... then I'd worry about integrating the screen with the computer.

 

Most GUI (Graphical User Interface) software nowadays establishes an object on the screen, and reports events that happen to that object, like clicking on it. Pressure on the screen in a given area will be reported back as an event to the object living there, and the 'click' action will be executed.

I'd say there's no chance that a device only sending the Prius a video signal would get a lot of use out of the touchscreen. This was one of the questions I had for CoastalDave about the DVD/MP3 player: how would it integrate with the screen?

Dave never replies, so I still don't know...

 

Just sending the Prius a video signal would absolutely not give you anything from the touch screen.

The touch screen itself will not send back an action event concerning the object that was clicked. The screen itself has absolutely no idea what is being displayed on itself. What is most likely returned in a x/y coordinate pair, which is then interpreted by the computer (in the dash board) to locate the proper UI object, which then fires an action event.

The goal here would be to intercept that x/y pair and send it to the laptop as a mouse movement event.

Dave's DVD player was, I believe, coming from the DVD player he plugged in. Since it is doubtful the DVD player has any form of input associated with the menu navigation it would not work for that.

 

I'm new here, hi everyone -- I'm looking for the explanation on how to get your external composite video up on the Prius LCD screen in the first place. It seems like everyone here already knows that, please point me to that info if it's on a different thread. Thanks!
sodium11

 

We know it is possible, but we don't know how yet.

Coastal Dave (http://www.coastaletech.com) is working on a modification to allow external video sources. It isn't complete yet for the 2004 model, so we are all waiting too.

 

I have been experimenting in preparation for installing a mini-ITX computer in the dash. Here's a trial screen shot:

This was done using a GrandTec Ultimate XP Pro video converter: http://www.grandtec.com/xppro.htm
I'll be ready with more details when I've done a little more work.

 

whoa that is neat! hmmm next is getting winamp to play some mp3s through the car speakers!

 

I think the holy grail of all of this is still the original focus of the topic. Figuring out how to intercept touchscreen signals and send them to a serial or usb port to be interpreted as a mouse. That would be really cool.

 

Does anyone know the native resolution of the Prius LCD? Is there a digital/DVI interface to the screen?

If we can get that (or composite video input failing the above) and touchscreen support, that would be awesome.

 

I wish I knew how to read wiring diagrams better, but I'll hopefully get some help this coming weekend when I'm visiting family who have more experience with cars and electrical wiring than myself. That being said, I'm not planning on experimenting on my car at all. However, if I can find which wires carry the video signal, that would make me very happy. Not counting on it though, but we'll see.

-m.