Re: Touchscreen hardware hacking/driver hacking.

["Dmitry Torokhov" <dtor@insightbb.com>]

On 10/17/06, Greg.Chandler@wellsfargo.com <Greg.Chandler@wellsfargo.com> wrote:
>
> I'm working on a prototype Hitachi tablet, it uses a Fujitsu 4-wire
> resistive touchscreen. {10.4" I think}
> I've found that windows-xp embedded uses a generic ps/2 driver for the
> device.
>
> I've ripped this thing to pieces on several occasions looking for chips
> to help the porting, my problem is that I can not find the
> analog-digital converter for this thing.  The connector goes to a
> surface mount header on an 8 layer board.
> I loose the traces almost instantly.  Given that I can't find the
> converter anywhere what should I do next?
>
> I've done my homework and found that this HAS to be either serial or usb
> attached according to Fujitsu.
> Aparently it's neither.  There are no unknown USB devices {or known
> matching}, and there is no activity on the single serial port on the
> system.  Since the windows driver uses PS/2 as the interface I have a
> horrible feeling this thing has an interpretation layer that makes it a
> PS/2 mouse, and that may or may not royally be a nightmare.
>

The touchscreen might need a "magic knock" to activate. You might try
to see what data wondows driver sends to PS/2 port.

Also check of Lifebook touchscreen protocol will work for you. You
will need to adjust DMI table in drivers/input/mouse/lifebook.c/

> I would have posted this to a different group but there is no "input"
> mailing list.
>

linux-input@atrey.karlin.mff.cuni.cz

But you must be subscribed to post otherwise list just drops your
mails on the floor.

-- 
Dmitry