Lilliput loses calibration data

Spartan117 · 07-26-2007, 09:46 AM

Hi,

some searching revealed that similar problems have been brought up before, but I couldn't find any threads where someone actually figured it out

So, here goes:

When i first got my 8" lilliput touchscreen, before first calibration, it was almost as if the screen was upside down. Pressing the center top resulted in a click on center bottom. Pressing left bottom resulted in a click on left top. Center screen clicks worked fine.

So i calibrated it, and it worked fine, through several reboots/shutdowns and even short power outages. However, after longer periods without power (maybe an hour or so), the calibration was reset to "factory state" as described above.

The carputer and screen won't have power unless the ignition is on, and ofcourse I don't want to recalibrate every morning. So;

- Does anyone know why this happens?

- Is there any way to "programatically" calibrate it? (As in, calibrate it once, then "reinsert" those settings with a startup script or something?)

- Where are the settings stored? In the screen itself? In the registry?

tbird2340 · 10-29-2007, 02:44 PM

I have a similar problem. It seems to lose calibration randomly.. When I recalibrate it works perfect so that makes me think it's not a touchscreen / hardware issue. I would think the settings MUST be stored somewhere.

Would be nice to reload them each startup or even have a shortcut to manually force the settings.

Spartan117 · 10-30-2007, 06:28 AM

Old threads come to life again

First, yes, the calibration data is saved in the windows registry. I can't remember the exact key, but running sysinternal's regmon-utility while saving calibration data will tell you where it is.

Second, here's what my actual problem was.. :-) The loss of calibration wasn't as random as I thought, it actually happened whenever I connected or disconnected other USB devices before booting the computer up.
The thing is, all your usb devices will be enumerated and assigned an ID on computer startup. If the lilliput doesn't have the exact same ID (because something changed), it won't be able to locate the correct calibration data from the registry.

Don't know if this is why you're having problems as well, but hopefully it helped. If not, let me know.. Best of luck!

tbird2340 · 10-30-2007, 08:04 AM

Thanks for the reply.. I'm not disconnecting / reconnecting any USB devices so I don't think that applies to my problem.

Thanks again!

Spartan117 · 10-30-2007, 08:38 AM

Are you running EWF or any other tools for write protection?

tbird2340 · 10-30-2007, 08:42 AM

Nope.. The only thing that isn't standard about my install is that I enabled minlogon and have a bat file to go from it to winlogon but I doubt that has anything to do with it.

Spartan117 · 10-30-2007, 08:47 AM

.. Unless the calibration settings are tied to user profiles.
Grab regmon, run it while saving the calibration data, then browse that area in registry. If you have more than one similar set of keys, you know it's having problems finding the old data for whatever reason (different USB ID, different user profile, etc).

tbird2340 · 10-30-2007, 08:52 AM

Will try that out. Thanks