New Build (with pictures) ### Digitizer II (UD1212-R) + Acer 15'' Laptop ###

[bernard]

btw, the recent post talking about a working serial - usb adapter is here:  http://forum.bongofish.co.uk/index.php?topic=1722.0

[Jodas]

thank you. is this the right one? http://www.usbmax.com/u232-p9_mct_u232-p9_db-9_serial__adapter_high_speed_230k_usb_serial_rs-232_.cfm
iam also following this thread too: http://forum.bongofish.co.uk/index.php?topic=1659.90
and iam searching an cheap notebook on ebay.
any suggestion to system configuration?
mine are: 1,5ghz 1gb ram 15,4'' winxp (maybe linux) -> painterX (gimp)

[bernard]

I just did a test run with the wacom board:  I was able to inject 5v into it ! yay!

As I suspected, the injection point is right out of the voltage regulator (left side of IC102, near C106, I hooked myself directly onto the regulator leg).  I also computed how much milliamp it was pulling on the 5v:  ~97.5mA  -- we can say 100mA.  Which seems to be within USB limits.

BTW, somehow the mA reading was also 100mA when connected through the normal 9v volt input power (same for 12v!) (the input power can be anything from 9v to 12v -- and it is true, below 9v it starts failing). That means the higher the voltage, the more "power" (watt) it is pulling. So feeding 5v is more economic than feeding 12v or 9v.

Now my test is not fully completed because I had no PC connected to it -- I only had the little led on the board to tell me that it is functioning and accepting the pen.  

I quickly looked at the RS-232 on the board -- and *I think I was wrong*:  it seems to use the 5v supply and not the 9-12v (!) -- The next thing to test would be to connect a PC to it (install drivers, blah, blah blah  ) and check if the serial port is functioning correctly with the 5v supply. That also means that the sparkplug FTDI breakout board might not be required (neither the hack to find the proper signals to bypass the serial port driver) and a standard usb-serial converted could work.  On the other hand, the FTDI breakout board solution might prove better in terms of energy efficiency (we would bypass/remove another chip from the equation).  Of course, most of the power is going to the LCD backlight, but hey, it is good to note our options here.

Note: If this setup is to be made permanent, I would remove the regulator or at least lift/cut its left leg -- so we disconnect everything on that side of the circuit -- not sure how the regulator likes it in the long run to be feed power from its output while nothing is coming in its input. Probably not that good.

Note2: when injecting the 5v it would be better to leave the main switch in the OFF position -- that isolates more of the circuits.

[Jodas]

Bernard, u're not a normal moderator. You must be a good friend of chuck norris!
Many, many thanks! U are a real powermember...
*Thumbs up*

[Jodas]

mini-update:

i found this about the IC102: http://www.datasheetcatalog.org/datasheet/toshiba/4143.pdf
this is about the rom M37702S4AFP: http://datasheet.octopart.com/M37702S4AFP-Mitsubishi-datasheet-104693.pdf
and this is about the Eprom: http://pdf1.alldatasheet.com/datasheet-pdf/view/74508/MCNIX/27C512-15.html
i don't know it's useful.

next step is testing the usb-output. i need steady 5V and not 4,7V or other.
at last i have to buy a usb-serial connector. when its done i can build a first test setup and start a build log.

[bernard]

Just to let you know: I am currently building a little project to convert ADB-based (and later Serial-based) wacom boards to *USB*.  The advantage is that your board will be seen on the Host machine as a USB device and thus you can use the native USB Wacom drivers.

I am using a board called Teensy (18$ US) which provide 5vcc output (from the USB of course) -- but you can program the stuff to tell the host how many mA you want (up to 500mA I think). You last post makes me wonder if this is really a precise 5V -- but I would suspect it should not be too far from it.

The Teensy has a serial port -- but at TTL levels --  (not RS-232 levels) -- but that only means you would need to hook "behind" the RS-232 line driver chip. -- unless you make the reverse-conversion  (TTL->RS232->TTL) with extra hardware.

This project is not finished but is making progress.  http://forum.bongofish.co.uk/index.php?topic=1738.msg12302#msg12302  (and I talk a bit about interfacing a serial board here: http://forum.bongofish.co.uk/index.php?topic=1738.msg12398#msg12398) -- Since I have the exact same board as you, I will definitely find a solution for it. (just not sure when exactly).

[Jodas]

It's a bit embarrassing but i lost the original power supply. It is fallen in a big black box full of supply's.  
I fished around and found one with 12v and 200mA. Is this the right one?
Bernard please help me. My Princess is in another castle!

[bernard]

I do not have it handy to compare mine -- but we can just compare the specs.

12v sounds like the good voltage and 200mA is good enough to feed the 100mA I was measuring (anything higher than 100mA is good).

Check if it is really *DC* output voltage _=_=_ (not AC output -- dial up modems used AC-AC adapters so some of old adapters in one's "geek attic" might have those!).

Check the wiring in case it is reversed. To do that, make sure the ground side connects to the ground on the board (ground is virtually everywhere on the PCB -- even on screws I think).   To know the ground on the adapter you have to connect it to the wall outlet (without the wacom connected) and using a multimeter check which side is the "negative" (COM) one. (the black test lead normally) -- you should be reading a positive DC voltage value (not negative) with the black (COM) lead connected to ground. Reverse the leads to see the negative voltage just to be sure.

Of course check the connector itself (unpowered) to fit if it is a mechanically fits first!!

Side note: If it does not read 12v do not worry, these adapters often works correctly only under a minimal "load" (something has to be connected at the other end).

When it works, make sure you take a marker and write "WACOM" or something similar on it for the next time around 

[bernard]

Princess: LOL!!!!   

[Drewid]

Do you want me to move this thread into the build logs?

[Teky]

Hi Guys

I have a problem with my WACOM UD-1212-R when i put pen on digitizer the light stays red no response i have checked the pen on another pad i works fine
so i guess its the pad any suggestions