Category Archives: Wacom 24HD repair project

Wacom 24HD repair project

backlight driver problem finally solved and applied

5 Comments

Sorry about the wait, ive been busy with uni, so, so, so, soooooo busy, but i have been researching.

let me recap the final step of the backlight monitor driver issue, taking the signal from the monitor and having the microcontroller read that;

the cintiq generates a negative voltage analog signal, i have no clue why, but it does, possibly for safety reasons since this signal influences an oscillator circuit that generates high voltages, so little blips of high voltage will trend towards zero and short rather than overload the oscillator. maybe. anyway, reading a negative voltage isnt a simple thing, the first and most obvious solution was to find a negative voltage supply to run the microcontroller off of, if the input and output of a boost converter are totally isolated then ground is whatever pin you decide is ground, but finding negative regulators is hard and they come with some drama to boot.

Next solution which i had to learn about before trying to apply in uni, was voltage dividers with a pull down. the negative voltage signal would be used as the ground refference, so, id use the 0 – -5v signal, once divided, to pull the signal up and down by 2.5v. but there was issued with stability, and i had to protect the microcontroller from the negative voltage, there were too many unknowns and a lot of instability, and in the end i found out too the ADC of an ESP is not totally suited to this task to begin with, without some modifications.

ADS1015 12-Bit ADC- 4 Channel with Programmable Gain Amplifier

But finally i found a solution which is just totally perfect. I will be using an external ADC, the ADS1015. its a VERY high resolution analog voltage sensor essentially, costs about $3, but it has 4 channels which is the important part. ADCs cant read negative, thats a given, but what you CAN do, is rather than comparing ADC-ground, you can compare the difference between ADC1 and ADC3. this can be used to safely read the signal as-is, with high stability to the extent no software “smoothing”. just for refference, even averaging out 3 seconds of signal input on an ESP8266 resulted in oscillations which would cause the backlight to flicker. But using an external ADC chip none is required, aside from a capacitor on the actual signal itself. This solution is one that either did not exist when the project begin, or took some time for the pricing dropped before it was viable, or perhaps i was simply not educated enough to know to look for it, im not sure, but i found it now, and its very much plug and play, and essentially infallible. Im currently away on holiday until around the 13th of jan, when i get back i will be resuming and finishing the project before my semester break ends, to finish this once and for all.

After the 24HD backlight driver is done, i have a 22HD i obtained cheaply which will then receive my attention (inverter is fine but its LEDs are blown, so will be doing an attempted fix of the LED strip, or, replacing entirely), as well as some really cool other projects which i will post about in the next week or so.

Some have asked if i will be making and selling the backlight drivers premade, plug n play, the answer is yes, i have actually been prepairing for that among other things, thinking about and learning circuit fab. In the end an ESP is the ideal microcontroller for this just for the singular reason that, i can make 2 sets of code, one for a full featured board, either my kit, or a self-build of it, and then the other will be for an “open loop” version, which does not attempt to sense the backlight signal and instead relies on a web interface if you want to change how bright the screen is, so you just log into the ESPs own little wifi, go to its home page, enter the % brightness and thats that. taking the “on” signal of the monitor is a no brainer so this, unlike how my monitor is right now, would still turn off when turned off, it will just have less convenient brightness control, but it doesnt require anything more than the ESP microcontroller, stepdown and LEDs, plus a little wire, very simple and graspable for anyone.

I was considering initially to use an STM based microcontroller since for voltage sensing and, basically everything this project needed it was perfect, however, the silicon shortage hit hard and caused even the $2 bluepill pricing to skyrocket, and consequently, the STlinks also went up, meaning the buy in price for just one STM microcontroller will be something like $20-30 depending on where in the world you are, for something which last year cost $2-5.

My goal is to finalize this project once and for all before the end of Jan. finalizing the project consists of the following milestones:

  1. build (or rather, technically just assemble at this point) and install a fully functional backlight driver into my 24HD cintiq
  2. document the construction of the final driver which includes some more detailed dissasembly footage with VERY thorough photography.
  3. produce a final build instruction set for remaking it yourself, a parts list, and code
  4. publish code for a “lite” version where you change brightness through wifi instead of reading the signal generated by the monitor.

before the end of feburary, ideally, i want to do the following, i dont know the timeline so, im uncertain if i could, since a lot of things will be done for the first time like;

  • design a PCB schematic file for the replacement driver
  • self-etch or have the the PCB manufacturered (timeline for either is uncertain, iv never sent schematics to be manufactured before)
  • find the name of the cable connector the wacom uses internaly so nobody needs to do DIY cable splicing and can literally just go plug n play in the most literal sense . finding these is very difficult.
  • I will begin reselling self-made cables with labels attached if it turns out i can only bulk buy or only get un-wired connectors, or at very least just providing them at-cost to anyone who asks me for them, besides of course providing its name/part number for anyone to attempt to self-source.
  • finally, i will attempt to list the first batch of complete drivers for sale, bearing in mind though they are first batch/for testing. revision 0. I dont forsee how they could fail since the PCB will essentially be a sort of shield, or just mounting board rather than wiring all the bits together, but who knows. all it is is just a circuitboard to replace a wiring loom, but still, the first batch will be sold conditionally like a sort of beta testing.

In march ill see what improvements, if any, can be made, then if all looks good, ill make a bulk-order of the driver PCBs and assemble, as well as just start selling the circuit board with self-assembly kits (including the female connector so no wire-cutting is needed).

this timeline i think is fairly reasonable, as of now, besides the fact im not at home for the next 2 weeks, i have everything that will be needed already sitting and waiting. but the 2nd stage, things to be done in February, will be dependent upon transit and processing times of entities other than myself, ive been told it can be quick, and done locally, but, its something im unfamiliar with. If time ends up being an issue i do have the capacity to self-etch a few of my own boards too, but thats all extra stuff for consumer products. If this doesnt go as fast as id like, i do have the ability to make semi-assembled plug n play connectors for the kits that will be a little messy but, will be essentially impossible to muck up yourself, because for this project, not to downplay the competency of the end users, we are talking about artists, people who for a living have mastered art, which is arguably the polar opposite of electrical engineering, working on their, usually irreplaceable $2000 art monitor which is sometimes the center of their income. even i myself felt very unnerved when i first cracked open the monitor, so imagine how it must feel for someone who probably doesnt even know what they are doing, but NEEDS to do it. with those people in mind i plan to make the repair as simple as possible with the smallest margins for error that i can manage.

So thats that.

Later ill also be posting some updates on other projects i have going or planned. Im currently visiting the fam up north, and half the time im bored as heck, storming up SOOOO many ideas i want to do once i get home again. Among them will include beginning the official Ronox engineering youtube channel. the final documentation/ dissasembly and backlight construction and installation/reassembly video will be posted on the new channel, to kind of christen it, and while your subscription would be appreciated, for now theres no need. In case anyone is wondering why im changing channels/accounts, its because my account is, in a way, corrupted, or broken, stuck with certain settings i cant ever fix, and honestly, monetization is my goal, thats something you need to maintain, so having any manner of head start wont really make a difference, its just as hard to go from zero, as it is to start with 20% of the subscribers and view time necessary. Also i may have bungled the new account too calling it ronox engineering, instead of just ronox, which i might not be able to change, so theres that too, youll be seeing more of me soon and ill soon be getting VERY active, i have too many plans now to remain idle.

Post Views: 256
Arduino: 8266 Wifi controller, Wacom 24HD repair project

ESP generic websocket

Leave a comment

A websocket is basically in this context a webpage where when you connect to the ESP 8266 or 32 through your browser, it maintains or streams a live connection, without having to refresh the page to see changes, or transmit data. You can see live feedback, or say, use a slider bar to control something, a simple GET/POST page cant do that, it would rely on refreshing the whole page or clicking a button to do things, during which time it has to connect again, a websocket however keeps the connection open for as long as the page is running.

Anyways, due to circumstances i wont just yet be making the hard-wired backlight dimmer, however, since the project now runs on an ESP board anyway, why not utilize the wifi capabilities. Another project im about to work on, technically altering an existing project, requires an interface, a LIVE interface, for an RBG controller, it also needs live feedback on the microphone so i can improve the responsiveness.

Im going to make my own or adapt, a generic websocket and make it ready to go, super easy to use for people as is, as well as adding this feature to the backlight driver. So, all you have to do is navigate to a fixed IP address (if you forget it theres also tools you can use to scan, or just look up the ESPs IP from your router), type that IP into your browser and a page will pop up with a slider bar or just 2 buttons and a numerical output, click and hold one to raise the brightness, the other to lower, its less risky and fiddly than using a voltage divider to pull -5v up to 0-3V positive. Though i will also add code to the driver to connect a resistor to it and the ‘ON’ line so that the monitor switches off when that signal goes off

Eventually i will still produce the complete circuit but for now this is safer and simpler, and since i have active prending work requiring the use of my cintiq, i cant really justify the slight risk of me causing  problems by opening it again for the Nth time, since this time around im treading in uncharted waters, i also cant test anything using my scope to check for noise because that particular ground line when hooked up to the PC wants to leak a large amount of current out, enough to cause significant heating.

Anyway, the project will be completed soon, and in the comming days everyone will at least have everything they need to acheive a fully functional driver, with backlight and responds to the power button, its just going to take a few more weeks before i can have a completed driver that is a full replacement for the original

 


Post Views:
187
Uncategorised, Wacom 24HD repair project

A simple explanation of the wacom data scandal

5 Comments

To call this a scandal would be an overstatement, its embarrassing for wacom but it simply sounds worse than it is.  The origin of this story begins here https://robertheaton.com/2020/02/05/wacom-drawing-tablets-track-name-of-every-application-you-open/ 

Its a pretty involved story that seems to be about 50% explaining literally every step involved in the process of proving the nature of the exfiltration. (exfiltration is the opposite of infiltration, means to sneak something out rather than in), so ill try to explain this in a reasonably simple and concise manner.

Here it is; wacom collects a list of the headers of programs, their “names” if you will, that you open during periods of activity on your tablet. They read just the names of programs you open or click on right after or during periods you use your tablet.

The text in the header is what they will see. Just its name though.

Wacoms goal in this is to quietly add support for any and all software that a lot of its customers appear to be using, it takes the names of the software, and uploads it to their private database, thats it. Ill elaborate a bit later on why this is so important for wacom though.

The problem this creates; the implications are minor however, depending on your stance on privacy you might have a problem with it, personally i couldnt give less of a shit, sure, occasionally they will see other software i exit paint tool sai, paint or photoshop from but all they see is the names and a timestamp. The risk is that a wacom employee with clearance, which no employee should really have (since the point is only to count programs used A LOT by everyone), can see an individuals program habits and exploit this in a really complex and obscure way. After a ridiculous amount of effort that would leave a huge digital papertrail (meaning doing illegal stuff with this would easily lead to termination of employment or otherwise being caught), at best a would-be hacker/criminal could send you some phishing emails or a virus (you probably will not download or your AV will block) that exploits one of the programs it sees you using, the risk/return of such an attack is too high for too little in an obscure way.

what to take from this; this was a huge dick move by wacom, the information they take is handled poorly and collected aggressively, because it poses an extremely low threat to end users they proportioned their level of care accordingly. It changes nothing though. Off the top of my head, wacom could instead not use google for this service, and just directly download the analytical data, what this means is decimating the potential for abuse of the data. All methods of abuse involve using the google data profile to match a tablet user with an online identity, remove this and the problems vanish.

why would they do this?
Its simple, ask yourself, why does anyone bother using wacom products? They are the best out there! But why are they so much better than the limited competition? Because they natively have the widest support for software. I think you see where im getting with this. Wacom collects the names of the software people often use its tablets with so they can properly direct their driver development efforts where its needed most, as well as catching onto new software. Its odd isnt it that niche or obscure new software seems to pop up and natively support advanced pen functions right? Wacom actively tracks what software is used, other tablet makers however simply focus on basic support while emphasizing use on the giants like photoshop and clip studio paint. Others dont bother at all and just rely on windows drivers for compatibility.

Wacom does this to control a monopoly on the pen tablet and display market so they can continue to charge their obscene high prices for their products. Its a niche market as it is, wacom doesnt really make a huge amount of profit even though their prices are so high, so its extremely hard for anyone to butt in on their turf, and this is how they maintain control.

 

So, in conclusion, your private data is safe, basic common sense level web security awareness will trump anyone who gets their hands on your data, and wacom should be embarrassed and fix this poor exploitable handling of your data, as a matter of respect not security, there are better ways to do it that anonymize its users. As Robert Heaton says, in spite of everything “this is essentially just a mouse”.

 

And on a parting note, you can pretty easily block wacom services from connecting to the internet via your firewall, i recommend the free program “tinywall” it will block everything you dont approve of explicitly including windows services that some programs use to sneak analytic data from, you can temporarily enable it to check for driver updates, or simply just make a point to check wacoms site for driver updates to download manually if you permablock it from your windows firewall instead.

 


Post Views:
419
Uncategorised, Wacom 24HD repair project

Im back (again)

Leave a comment

I have been very busy, with moving, changing to a new campus, besides also studying. I plan to very soon finish the backlight driver, ill also make some revisions, namely, adding the ability to use ANY microcontroller for this. Specifically ill make it compatible with the ESP8266 series which are capable of reading a signal voltage and outputting PWM. The ESP8266 is a wifi board, but we wont be making use of that (but just for kicks i might add a web interface someday), its stupidly fast, its only $2, and most importantly, not only does it have a built in USB interface, you can even program the damn thing over the air, meaning if you ever, or i ever, find a bug in the code, you simply can just upload a patched version without having to open the monitor, you can set up the thing to act as a hotspot for situations like this.

Just to clarify, the reason this thing seems too good to be true is because it is. the ESP8266 is fundamentally designed to work like an adaptor but wemos and nodemcu have made expanded boards that fully use all the chips GPIOs, which arent actually many.  Can do some pretty intense processing, relatively speaking, though usually not while using wifi, also the wifi code usually takes up most of the space on board, usually when running solo, its digitally connected (not analog) to 1-wire or SPI protocol devices that make use of the fact it can only handle 2-3 data connections, for digital sensors and such. Unlike the STM32F1 Bluepill which can, though its strengths lie elsewhere.

Anyway, what we are asking of this board is trivial.

The reason i initially used the STM32 bluepill was i assumed i had to be able to accurately read a 600Hz PWM signal while also outputting a 10-20KHz PWM signal. this is something that is not easily done on an ESP. Also at the time the ESP cost twice as much.
Turns out though all you need is a single PWM peripheral running and use of the ADC to read the voltage. technically the STM32 is still better because itle read up to 5v, while the ESP only 3.3v, but, if you buy some 1% error tolerance resistors or better for the voltage divider, the issue will be moot, especially if i eventually manage to make a self callibration process, for which, it will be vastly better to be using the ESP, since you wont have to open the monitor again to add the program, hell, you can manually callibrate it from a web browser even, to  tell it what voltage is minimum brightness and what voltage is maximum, or you can just do all your brightness controlls through a browser too and totally ignore the need for any special interfacing, given the complexity of the OSD, this might actually work out better XD

Purely because using an external programmer can be a burden to beginners, and the ESP is now more supported than STM boards, and cheaper, ill switch this projects suport over to that. Anything though the ESP can run, can also be run on almost any other arduino too.

On a final note, to anyone posting comments, i get like 50 spam messages a week, if you want to share a link, break up your links or remove the http:// part, most websites trip my shitty spam checker. comments shouldnt need manual approval so feel free to double, tripple or etc post your questions until they pass, be sure not to use any rude language either. I dont mind if you have to post a bunch of times to make it come through. As a general rule, i think theres a pretty short list of safe websites so, just dont use any valid URLs in comments. also, dont add your website like it asks, thats a trap, i will change the user interface  to display an image saying “do not type anything in this bar, or your comment will automatically be deleted”, the spam bots always fill out random shit for the website url.

Feel free to say hello on my discord, i get mobile notifications from my server.


Post Views:
194
Arduino, Wacom 24HD repair project

Backlight driver code is done and ready to implement

8 Comments

But just for testing purposes, it might work fine as is, or it might jitter a little and constantly turn the brightness up and down, i havent yet implemented anything for stabilizing the output.

right now this code doesnt adjust the output at all, ill edit it later though so it does. But it is both reading and writing PWM signals, all that needs to be done is some quick math to set the output brightness value (0-1024)  to the PWM percentage of that, and do this only once every few seconds, furthermore, to ignore slight shifts in the brightness, or some other method for stabilizing the output.

 

Continue reading Backlight driver code is done and ready to implement →


Post Views:
769
Wacom 24HD repair project

I havent quit yet, but sorry about the wait

Leave a comment

I recently begun an apprenticeship and finished a term of university at the same time so ive been smashed. Also i finally started drawing seriously, so, thats pretty much where my free time has been going.

Probably over this weekend im going to open my wacom again, however, i will be only doing 2 things. 1; adding extension cables from the backlight driver cable, to one of the cable areas for easy access later and so i dont have to dismantle the monitor again. the driver will be outside however, so, i guess i WILL dismantle it again, but, i wont need to any time soon.
2; I forgot to plug the USB hub back in 😛
So, cant use my usb port on the monitor, which has proven annoying.

Beforehand i might have a look at some new strips i bought, if they have the same power and less yellowing, i might switch them out. Otherwise, i can live with what i have now, i probably wouldnt even notice if i didnt have a perfect colored LED monitor right next to this one.


Post Views:
349
Uncategorised, Wacom 24HD repair project

Im going to build a high powered custom LED strip for the wacom and anything else

1 Comment

Ive drawn up a model of the LED strip i have in mind. It is based on a 5.7mm long SMD LEDs, prefferebly 5736’s, but they arent too common, i may have to go with 5730s. I was going to go with the 5050s, or another LED but packed tighter, however, 5050s are a tad bit too big for the rails without going into multi layer PCBs which are just insanely expensive. I was also going to go with packing heaps of LEDs on the strip by turning them sideways, but, same reason, i couldnt, so ultimately this will end up being a modular larger version of the exact same strip. not that its bad or anything. this strip though will utilize parallel series of 4 instead of 3, meaning it can be safely run at 12v unregulated.

Continue reading Im going to build a high powered custom LED strip for the wacom and anything else →


Post Views:
1,164
Wacom 24HD repair project

Raw Monitor dissasembly and backlight installation videos now available

13 Comments
Heres the video links
Part 3 (working and comparison with real LED backlit display): https://mega.nz/#!jF4RSL5I!bn4SK65uxBnkQVmOyDXK4VzoAqdwQ_i6XemXYzvP9bc
im still working on editing a proper one to put on youtube.
It would be substantially edited down, annotated and include several photos i took during the recording to show how to do some of the trickier parts.

Post Views:
445
Product Testing, Uncategorised, Wacom 24HD repair project

Blog update: Im back. Was Sick. Also “website” field has been removed from comments due to mass spam attack from viagra salespeople

3 Comments

Ive been sick these past 2 weeks, I knew i should have held my breath walking past that coughing guy in the exam room, i bet everyone was put out of comission, sleep deprived caffeine hopped up engineering students, spending 3 hours in that small room with at least the one sick person.

Anywho, im good as new, to answer some questions:

Continue reading Blog update: Im back. Was Sick. Also “website” field has been removed from comments due to mass spam attack from viagra salespeople →


Post Views:
256