Converting Wacom UD-1212-R from Serial to USB

[Tymnus]

Hi folks. I am purchasing a "vintage" Wacom UD-1212-R from ebay. It will cost me about $10 plus shipping. Under direction of the Great Wizard Bernard, and his "waxbee project" I will be modifying this 12x12 board from a 12v serial version to a 5v USB interface.  

I will also be purchasing a Teensy USB Development Board ($16) to create the interface (http://www.pjrc.com/store/teensy.html) and an Axiotron Studio Pen - also from ebay - to replace the original pen. This pen will cost me between $10 - $30 depending on which model I go with.

This Wacom board can work off the USB 5V (power provided from the Teensy board). I can directly connect the (internal) serial signals to the Teensy 2.0. (TX/RX).  No extra electronics and circuitry required.

Estimated end cost for the board and supplies to modify, hopefully well under $100

I will document the experience here as the parts arrive and as I move through the modifications. I will include photos and any guidance and troubleshooting help I receive from Bernard or other folks wiser than myself!

[bernard]

peanut-butter-and-jam-sandwiches! Pof! USB plug magically sticking out!
Ok, I'll try to summarize electrical interface in this post.  

Warning: This mod will permanently disable the external serial & power connections. Playing with electronics is not without risks. You can break or burn anything including your fingers.  

It might look complex/intimidating, it isn't really. There are only 4 wires going to the Teensy and 2 others staying on the controller board. There is just a lot of text and explanation, that's all.

Please read it all before doing anything.

There are many ways of connecting the power and serial signals with varying levels of difficulty/cost/risk. This post only talk about the coolest/cheapest/riskier one. It permanently destroys the tablet external power & serial interfaces. (An "extreme" alternative solution wouldn't even need to open the Ultrapad case: it would be costly but also the safest for the tablet).   NOTE: such a solution exists and was done by Sicarus http://forum.bongofish.co.uk/index.php?topic=1993.msg17274#msg17274

Test
Like I said, this will break functionality. So if it does not work, you cannot "go back" to what it was before. It is thus important to know that stuff works (as much as possible) at every step.  For example, if you have the board in your hands try it to see that it works before.  If you do not have the pen, wait to get the pen before proceeding for the mod. You need to know it works before.

By trying I mean to (find a way to) power up the board and touch the tablet with the pen (both with the tip and eraser) and try the sideswitches. The "Led" should blink accordingly. If you see this, you are in pretty good shape.  If you do not have the power adapter to try this, then you have no choice but to skip this and try to hook the ground and power and do that test.

Test the Teensy alone
Simply connect it (with a usb cable) to the computer. You should see the led blink. This is the built-in software that paul programmed just before sending it to you. Of course, disconnect from computer before doing the soldering.

Multimeter
This can be done without a multimeter or continuity tester, but it is always better to have this type of tool around to check on every soldering. You can double-check if you connected to a nearby circuit by error or stuff like that.

Explanation of the mod

Serial Signals

There are 6 serial signals. They are not all needed. They go through a serial driver chip, the MC145406.  Here's the pinout of the chip (with the voltages while powered with no serial cable).




Table 1

Combined pinout of the serial cable up to the "TTL side" of the MC145406 (PC-DB9 is on the computer). The teensy understands the TTL signals. So we are essentially replacing all this.

------ Serial Cable ------   ----- MC145406 ---------- --Teensy-----
PC-DB9   Dir.   DB9-Tablet   RS (CP)    Dir TTL (CP)
-------- ---    ----------   ---------- --- ---------- -------------
 2-RXD   <--      2           7 (CP135) <-- 10           D2 (RXD)
 3-TXD   -->      3           6 (CP136) --> 11           D3 (TXD)
 8-CTS   <--      4           5         <-- 12 (CP145)
 7-RTS   -->      5           4         --> 13
 4-DTR   -->      6           2         --> 15
 5-GND            7          *** Ground Plane    
 9v..12v          8          *** Power
 6-DSR   <--      9           3         <-- 14 (CP148)

 Pins not listed are N.C. (Not Connected)


Table 2

Summarizes the modification:

                    MC145406 (removed)
Teensy      Board   Dir TTL side   signal
--------    ------  --- ---------- ------
D2 (RXD)            <-- 10         (RXD)
D3 (TXD)            --> 11         (TXD)
GND         Ground
            N.C.    <-- 12 (CP145) (CTS)
            Ground  --> 13         (RTS)
            Ground  --> 15         (DTR)
            N.C.    <-- 14 (CP148) (DSR)

VCC         IC102 left leg pad (near C106)


Overall view of the mod:



Note that in this case, the teensy is positioned for the picture, normally you have to find a secure spot that would fit in the case.  (BTW, I removed the switch because it would become irrelevant & actually confusing and to make space for the teensy board (removed by cutting the 3 legs then pulling it - it was glued to the PCB).

The fun part

#1: GND
The teensy GND (ground) signal needs to be connected to the "Ground plane". (lots of places to solder on the board).  NOTE: the board has a little coating and it might be required to scratch the surface a little to access the metal.  

#2: 5V
This is the IC102 black square component (TA7805F -- the 5V voltage regulator). Either you find a way to remove it or you just cut the left leg (the one near C106). This is where the 5V needs to be injected. Note that for soldering a wire, you could hook yourself anywhere that trace is going, and in particular on the right leg pad of C107 (near the + sign) or in one of the vias (i.e. the holes).



Teensy (viewed from the back):



#3: Test
At this stage it would be important to test your tablet, the next step is more delicate and thus it would be nice to know that (most of) the board works fine before digging into this.

Essentially with the GND and VCC plugged in (black & red wires in the pictures) plug the teensy USB cable. (start with the small connector on the teensy, then finish with the connector on the computer).  The first time you do this is called a "smoke test". If you see your computer powering down instantly, pull the plug right-away, something is badly connected.

#4: Remove the MC145406
Best is to use a Dremel to cut all the legs then carefully unsolder all dangling legs on the board without lifting/breaking the "pads" (the pad is the metalic thing on the board where the chip legs are soldered to). If a pad (that is required in the modification) is broken just follow the trace and find another place on the board to solder your wire on.  




The most important serial signals are RXD/TXD (pin 10 and pin 11). The others are either ignored (CTS/DSR) or must be grounded (DTR/RTS).

Detail soldering:


#5: Ground DTR and RTS
These are pin 13 and 15 -- the two bottom yellow wires in the pictures. Now that the MC145406 chip is gone, these are now "floating" (electrically), and should be grounded. This is also important because the UD board might decide to not send any serial data if the floating TTL value decides to go high. Follow the table 2 and the pictures to decide how you are going to do this.

When I say "grounded" I mean connect to the ground (or negative side often seen depicted with the color "black"). There is a lot of "ground" connections on the board -- we call this a ground "plane". It actually covers all the "unused" areas of the PCB.

There are a few holes (called vias) that are big enough to fit a bigger wire gauge. I picked two of them below.

Make sure the other pins (like 16, 14 and 12) are not touching the wires. This is probably one of the most delicate soldering part of this mod.

#5: RXD and TXD
These are pin 10 and 11 respectively. Use a longer wire for those as they must go to the Teensy. Check table 2 to know which goes where on the Teensy.

Notice that the MC145406 pads must not be stressed (or they will "lift") so the two wires are held securely by going through a hole at the top of the board (see pictures). You can do it anyway you like, but try to make sure there is (and will be) no stress on the MC145406 pads, these are fragile.  EDIT: you cannot use the same holes to secure the wires if you want to re-use the same case since a piece of the actually goes through those holes to "hold" the board.  If you remove the power switch there are 2 round holes hidden under it that could serve this purpose as well.

NOTE: if you have 28 gauge wires (smaller than the ones I used for this mod), you can fit the wire in tiny vias (holes) that connects to the pad and solder there. It would typically be more solid as a soldering point (using a smaller wire by itself is more fragile thought if you move it back and forth -- that is a tradeoff).

Soldering tip:  position the wire as shown and make sure it is held down in position on top of the pad. Then simply apply the soldering to the wire and it will "fall" to the pad and everything will solder. It does not take much to hold the wire. Make sure there is as little stress as possible on the wire and soldering joint. Plan the wire final shape and position beforehand.

#6: Test
Do the same type of test just to be sure nothing major is broken. At this point, it is not expected that the mouse is moving (we need to do the firmware part for this), just that the led blinks when you operate the pen.

Next step is the software (WaxBee) -- see post below.

[Drewid]

Well - I have a spare UD1212 tablet, and I could really do with it running in Windows 7  so I'm going to have to give this a try.

[bernard]

Using waxbee config utility, pick (File->New from template), select the "UD-1212-R to Intuos2 XD-1218-U" template, then select Firmware -> Program device. Connect the teensy usb cable (if not already connected) and press the little button on the Teensy.  Once finished, unplug/replug the USB connection.  You should now have an Intuos2!



Get the distribution package here: http://code.google.com/p/waxbee/  

Note: if your system is not Windows 64 bit, the "program device" will not work (yet). The programming is done differently (please read the readme.html file in the distribution package).

[Tymnus]

Quick update: As of today, all of the necessary parts for this project have arrived! Now... to get my tools together and begin. I will do my best to photograph the process.

Thank you Bernard for the excellent guidance. I feel pretty confident to move forward.

Cheers!
Tymnus

[Tymnus]

Ok... jumping in tonight. It's finally cool enough on this hot summer's night to fire up the soldering system. I am fairly intimidated about "Dremeling" the legs off of the 'MC145406' so I think I will try to de-solder and remove without cutting.

(***After a long time***)


That took forever!!! I should have used the Dremel. However, all is well that ends well. I maged to desolder without damaging anything. (I think.)

Not to start attaching the wires.  

[bernard]

Cool!

Dremel:  Yeah, it is a bit scary. You have to carefully cut the legs "close" to the chip "box" to stay away from the PCB as much as possible. Unsoldering everything is very difficult because the chip won't lift until all is desoldered -- at least on one side.  Some might get away with a fine cutter or a sharp exacto knife.

I will add a few guidelines to the post for "testing as you go". It is always better to check stuff at each step (as much as possible) to not be stuck at the end wondering why the "whole" thing is not working. Since we are "destroying" stuff a little, you cannot "go back".

[bernard]

Here's a picture of how the UD-1212-R case could be modified to fit the Teensy:



1- I removed both the DB9 and power switch
2- there is no holes on the teensy for screws, so tie-wrap we use. It is very sturdy. I drilled holes for the tie wrap.
3- The led on the Teensy is visible (if needed in case of troubleshooting)
4- The reset button is accessible (to re-flash a new version)
5- I used a big, transparent heat shrink tube (2:1 shrink ratio, diameter 18). Did a hole for the button (else the shrink tube kept it pressed down!). Cutting this hole is difficult to do cleanly. **note on this below
6- The USB cable can be changed without opening the case
7- This is not perfect: I should have done a little groove at the bottom of the case for the tie wrap to be a bit more flush. I mean, without the special UD-1212-R angle "shims" installed, the tie-wrap creates a very subtle bump and the tablet does not sit super-straight on the desk.



**Just got an idea: I should have put a little ~1mm shim on the button while heating the heat shrink tube. In such a way to be able to pull it out afterwards.  That would essentially "reserve" the space for the button to stay "unpressed". Then when one needs to press it, you just press through the plastic.  No need to cut a little hole like I had to do.

[Tymnus]

My Fellow Bongoloids,

We have lift off!!! I followed all instructions posted here by Bernard... as best as I could with my rusty soldering skills. I did make a couple of boo-boos while soldering - but managed to make all of the necessary connections anyway.

Tested with my meter to be sure. After installing the latest Wacom Drivers, my Wacom UD-1212-R is powered though the USB and is recognized as an Intuos2!!!

Awesome!!! If anyone else wants to try this... I highly recommend!

~Tymnus

[Tymnus]

Update: A couple of issues.

1. There is an intermittent issue with the tablet becoming inactive at random intervals. I will be mid-stroke, and the pen will cease to move the cursor. I can regain control by clicking anywhere in the top row of numbered menu buttons on the UD-1212-R. Once touching anywhere in that region, control is regained over movement of the cursor.

It also seems that when this occurs, if I wait about 10 seconds control will return. This problem occurs in photoshop, corel, and within any regular windows 7 navigation. Seems indiscriminate of software.

2. When using Artrage, the pen will not draw to the canvas. I will begin a stroke but it will remain fixed in a single position where I first touched the canvas, leaving an ever darkening spot until I lift the pen again.

I have checked my solder points and they all seem ok. I have also kept an eye on the device manager to see if the device disapears or something like that when this occurs. I see no changes there.

Interestingly, when I run the diagnose feature from the Wacom Tablet Properties interface I notice that I get the message "Proximity: Out" whenever the problem occurs. Strangely  - the tablet seems to see the pen as the light on the Wacom still changes color in response to the pen - even though there is no movement.

Thanks for tuning in... I will try to keep you posted. That's all for now. 

[bernard]

This might just be a bug in my software. We can certainly work that out. We can turn on the debugging features and I can work with you to try to pinpoint the issue.  I will try again myself here with my UD-1212-R to see if I have a similar problem. I am sure we can fix this relatively easily.

EDIT: mine appears to be rock-solid. (?)  I tried drawing in Art Rage for 15 minutes and it worked without a single glitch.

EDIT2: we found the issue. It was that the serial tablet reports only when the pen moves or something changed in the button/pressure status (which I is normal).  On the other hand, the wacom USB tablets continues to send packets even if nothing changed. The Wacom driver seems to not like it when no more packets are coming in -- it is interpreted as a "hum, no packets in the last 60 ms, it must be dead! So let's end the stroke right now".  So in version 0.8 I implemented an "idle time" protection that simply "repeats" the last packet that was sent when no activity occured "within a stroke". There is a new option to set the number of ms to wait before repeating the previous packet. That solved it wonderfully for Tymnus!

[Tymnus]

Well rub it in! 

Mine is still suffering with its random freezing issue. Thanks for the updates to the software, and working with me on the debugging! Sorry I have been absent a bit... I have been a bit distracted by life, work, and of course by the fact that I received a package from China with my controller kit from NYCtouch!!! I will post some photos of my little monster soon!!!

Anyhow... as for ArtRage, I realized that everything seems to work fine except for the airbrush tool. It just freezes in one location drawing an ever darkening dot as if I were staying in one location. But I am actually moving all around attempting to make lines. The other tools seems to work well.

More soon!
Tymn

[luxeomni]

i succesffully turn a ud1212r into a intuos 2 thanks to Bernard and waxbee !

Just did couple of tests in photoshop, no problem. I'll try to see if i get problems in long sessions.

The only issue is that the pen seems a little weak, i can't pull my hand very high without losing signal very quickly, i ll soon receive axiotron pens, so i ll test with them too.

[bernard]

Hey! Cool to know this is getting used more and more!  Was there any glitches you went through?  Or stuff you that was not clear enough the first time around?

[xuz]

Hi bernard and folks,

I have XD-0608-R intuos 2 serial version that I want to convert to USB.
I've used it since windows 98 to ME to XP to Vista to 7 x64, through about 5 computers. Installation since Vista has been on frustrating.
I've had it with these #!#$!%!#$ on this !$!#%!$! plane!!!



--- I do not want to hijack this thread. If I am, kindly let me know, and I'll start a new XD-0608-R thread ---

So I opened it up. Couple things to note.

1) The 5V regulator is the same, so that part is easy.

2) The communication chip on  UD-1212-R is MC145406
On XD-0608-R it is ADM202JRN.

I am not too sure but it seem likes it's taking internal TTLs and pumping it up to RS232 level.
Would you help me with wiring that'd make ADM202JRN be compatible with teensy?
Also, would the waxbee program work for XD-0608-R or may be it won't?

Another question is, I don't have teensy, but I do have a generic USB to UART Bridge.
(Silab CP2102) I usually use this to interface with my standard microcontroller (ATMEGA from atmel).
The interface is pretty similar to teensy. (6pins, RXD, TXD, GND, Reset, 5V, 3.3V)
Would this USB/UART bridge work just as well?
This was answered in http://forum.bongofish.co.uk/index.php?topic=1930.0;prev_next=next#new
Just sent in the order for teensy.

Thanks for any hint in advance. I have to say, I'm pretty encouraged by other folks' success with UD-1212.