Friday, November 3, 2017

Turn "old tablet PC" into "LCD tablet"

Hi all.

I want to share my recent DIY work.

This post will show you how to turn old tablet PC into LCD tablet.

The example is HP's 2710p tablet PC.

2710p is quite old, so it has low resolution (1280*800) and low pressure sensitivity (256 level).
However, this model uses LED backlight which guarantees long life time, and it is confirmed that it can be turned into LCD tablet.
In addition, necessary parts are cheap.

The first guy modified this model is here-> http://forum.bongofish.co.uk/index.php?topic=2325.0
Every procedure is same with him.

Here are what you need:
-LCD : HV121WX5
-Wacom board: SU-12W18A-01X
(or 2710p LCD+digitizer assembly, grab it on ebay!)
-Teensy 2.0 board : you must use 2.0 https://www.pjrc.com/store/teensy.html
-3.3v regulator: https://www.pjrc.com/store/mcp1825.html
-VGA board: most of VGA boards work fine for the LCD
-14pin LVDS cable (optional): you can easily connect teensy board to the wacom board

Long time ago, I bought this LCD+digitizer assembly for 2710p.

This is the VGA board, and it has NOVATEK chip.
In my memory, I bought this from taobao.com, but cannot remember from which seller I bought it.

This is teensy 2.0 board.
I've used this board for several purposes, so the condition seems not ok....
Anyway it works fine luckly after some tricky work :)

This is important part.
9, 10, 13, and 14 pins (wacom board) will be connected to the teensy board as follows:

pin 9 -> D2
pin 10 -> D3
pin13 -> VCC
pin 14 -> GND

You can directly solder wires onto the pins, but I recommend to use 14 pin LVDS cable.


Connection is complete!

Now, you have to download Waxbee. 
https://github.com/popbee/waxbee/releases/tag/waxbee-0-16
Waxbee upload a program on teensy to drive the wacom board on your computer.
(You have to install JAVA to use Waxbee.)

Once the teensy is connected to your PC (by USB), follow the steps.

1. In Waxbee, click File-New from Template, and choose "Penenabled ISDV4 to Intuos2 12x18.tmpl.txt".

2. click File-Raw Config Editing, then edit some as follows



3. click Firmware-Program device, and reset your teensy.

4. unplug the USB cable, and re-plug.

5. Install a legacy wacom driver (Intuos 2 (XD) 6.2.0w5http://www.wacom.com/en-gb/support/intuos-pro-support

The wacome board will work if you followed the steps.



Once you have checked your wacom board, it's time to connect VGA board to your LCD.

If the VGA board is fine, you will have no problem.

Now, you have a cheap working LCD tablet!



Once everything is done, a housing depends on you.
In my case, I used the 2710p frame.





I hope you enjoyed this post. Thanks!