Showing posts with label Reuse. Show all posts
Showing posts with label Reuse. Show all posts

Tuesday, 11 February 2014

Wacom Graphics Tablet from broken HP TX2000 tablet PC

Next Steps
  • LVDS to VGA boards have become more common since I originally did this project, I might get one and turn it into a complete external touchscreen monitor
Version 1
I acquired one of these laptops after it malfunctioned. Apparently this is a known issue of overheating.
I initially tried to fix it by reseating the graphics chip, which worked for a while, however it quickly began to malfunction again.

So I tore it apart to see if there was anything useful I could scavenge.

It's well documented that laptop screens are near-impossible to get working as standalone monitors, due to the differences in the way they communicate with the computer compared to regular screens, so instead I set about trying to make the touch screen work as a standalone tablet.

I was expecting this to be quite difficult. Turns it it's one of the easiest hacks I've ever done.

There's a 9 pin connector that connects the digitizer. In amongst those 9 pins, there's USB pins.

It's not a simple case of soldering on a full USB plug though, the tablet works at a lower voltage (3.3v) than the standard 5V.

To overcome this, putting 3 N4148 diodes on the voltage line was sufficient to drop the power to a usable level. This isn't an exact measurement, but it works.

A standard Fedora 16 desktop install comes with wacom drivers pre-installed, so the software side of things was basically plug-and-play. The only change I made was to change the pen mapping from absolute to relative, which was better suited to my monitor setup.