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16  Screen Tablet malarky / Heyaaaalpppp / Re: dropped 21UX 2nd gen not responding to stylus. on: August 08, 2017, 04:41:06 PM
Yeah. All we can do at this moment is wait for more info or photos and keep guessing Smiley

XDjackieXD: You have different experience than me. Can You wrote Your guesses what may be wrong?
17  Screen Tablet malarky / Heyaaaalpppp / Re: dropped 21UX 2nd gen not responding to stylus. on: August 06, 2017, 02:30:30 PM
Quartz oscillator is the most fragile component of most electronic boards (except displays and connectors).
Broken solder joints or traces on PCB may be unrepairable. Especially when board is attached to heat sensitive flex circuit (antennas).
18  Screen Tablet malarky / Heyaaaalpppp / Re: dropped 21UX 2nd gen not responding to stylus. on: August 05, 2017, 11:37:20 PM
I have two Tablet-PC screens.
T5010 have typical construction: single PCB for Wacom chips and flat-flex circuit for antennas.
ST5111 have two solid boards, one with chips, second with antennas. Both boards are connected via board to board connector.
If You have second option, then connector may just need to reconnect and that's all. If connector wasn't the problem I guess broken quartz oscillator (hard to replace in home, easy for electronic service). If still nothing then repair of broken digitizer may be impossible or even more expensive than new digitizer.
19  Screen Tablet malarky / Heyaaaalpppp / Re: Salvaging touchscreen from a Toshiba Portege M780 on: August 05, 2017, 11:12:30 PM
Hello.

As I found after very short research, base models of M700, M750 and M780 have the same or very similar screens - LCD + Wacom EMR digitizer + resistive single-touch. Probably M700 have CCFL backlight while M780 have LED backlight.
I talk about base models, 1280 x 800 px. M750 have hi-res screens as option, 1400 x 1050 px. If that screen have LED backlight, You should look for it. As I figured 1280 x 800px have very limited compatibility - some video cards autodetect this resolution, most not but I can force specific resolution, few doesn't accept and cannot force specific resolution. That's sad.


Back to topic. LCD (glass + drivers), LCD backlight, EMR digitizer and touch digitizer are separate devices. You need special adapter for each.
1. This TabletPC is relatively old. I assume that LCD gave LVDS interface. You need to use VGA->LVDS or HDMI->LVDS converter to connect LCD to PC. I mean active converter + special cable between converter and LCD. You can buy universal converter with wide range of supported resolution (select via jumpers or upload via USB stick) or specialized converter (programmed by seller). You cannot make connector for LCD panel. You can easily buy special cable (price may vary depend on type of connector) or buy LCD with cable, cut motherboard connector and make DIY wiring.
2. CCFL backlight have separated driver, always hidden near LCD module. You need to find pinout for that module and connect it. LED backlight have independent circuit located at the same circuit board as rest of LCD things. It use the same connector too, just have separate pins. Pinout are available at LCD datasheet. BTW, LCD is useless without datasheet or at least pinout.
3. There are tree types of EMR digitizers.
You can found one with USB interface - add 3V3 voltage regulator and proper USB connector, that's all.
You can also found one with RS232 interface - add RS232 to RS232-TTL and digitizer will be usable on Linux or WinXP, or add WasBee converter and digitizer will be available on Linux, modern win (probably Mac too).
Last type have unknown interface between EMR digitizer and touch digitizer but known interface between one of them and motherboard - usually USB but sometimes RS232. So don't worry. WaxBee doesn't cost fortune and playing with these things are worth.
4. Portege series use single touch resistive panel - can be used with any tool that aren't too sharp to scratch it. That panel are made of solid back plane, air gap and thin foil on top.
As You wrote, You don't need that part so You can safety disconnect panel from dedicated hardware, maybe remove some parts inside. Really no issues here.
But I have to say something about that touch panel itself. IMHO drawing over resistive touchscreen wasn't the best option. I recommend You to replace touch panel with layer of glass/plastic or chose different tablet to play with it. But that's my opinion based on regular resistive touch devices. Maybe that screen have special durable version, who knows.
20  Screen Tablet malarky / Heyaaaalpppp / Re: Hacking Wacom Drivers... on: August 01, 2017, 09:41:36 PM
WaxBee? Sadly no. WaxBee is designed as one way converter: RS232 or ADB as input, USB as output. This tabletPC is relatively modern and I'm sure that digitizer have USB interface (probably single USB for both EMR and capacitive touch), nothing else. You may chose uC with two USB interfaces, one host (or OTG) and one device (or OTG). This uC will receive USB packets and translate it.

Second solution: I'm sure that Linux still can use legacy Wacom drivers and handle this digitizer as regular tablet with full options available.

Third solution: maybe this digitizer can detect pen ID? If yes, there might be possibility to use different pens with different button assignment.
https://www.phonearena.com/news/Note-the-progress-the-evolution-of-the-Samsung-S-Pen-from-the-original-phablet-to-the-Note-7_id83943

And last option: users feedback. Few hundreds of user comments and samsung may notice the problem.
21  Screen Tablet malarky / Build Logs / Re: Intuos4 XL (x2) 40" 4K or 27" Apple Display on: July 30, 2017, 07:22:44 PM
First, chose slim display. Second, chose single tablet.

1. Chose thin display with backlight hidden on the edges - standard for tablets and smaller screens.
There are also thick displays with light source are hidden on the back of LCD. Some of these models have "local dimming" - backlight are divided into sestions and controlled independently. That type of backlight makes display impossible to modify because thickness of backlight module.

2. You cannot connect two tablets to make one bigger. You can place two tablets close but there bust be small gap between. If no, interferences between tablets will occurs.
If You want to draw on half of display and have images, toolbars, settings, etc on second half - OK. If You want to draw in the middle - forget about it.
22  Screen Tablet malarky / Build Logs / Re: Unneeded-IQ on: July 08, 2017, 07:09:56 PM
If I see correctly, DVI connector miss many pins. This must be DVI-A input plus some funny pins for PnP, monitor ID and hot-plug detection. Definitely no digital input.

Nice work with backlight. If I see correctly, this screen are designed to easily swap backlight elements.

P.S. linked video doesn't work.
23  General Category / General Chat / reMarkable - Cintiq with E-ink? on: July 04, 2017, 09:48:11 PM
https://getremarkable.com/
reMarkable is another e-book reader. You should hear about Kindle, Nook, Tolino, etc... But reMarkable also contains EMR digitizer (there are only few eink readers with EMR digitizer) and probably resistive touchscreen. You can draw and highlight text using any pen, but dedicated battery-less pen are designed to give You the best paper-like feel. And pen are sold separately to maximize company income.
That's all information that I can found on official website.

Why I copy that on tablet forum? Because I found non-official information that Wacom wasn't only supplier for EMR digitizers. Some sources say that Wacom help them with digitizer, top layer finishing (paper-like drawing), pen and e-ink display.
What You think about news? IMHO Wacom have good deal with them and within few years we should see new Cintiq model with outdoor-readable grayscale display. Maybe even new class class of devices - portable notepad that can act as a regular tablet or that You can bring outside and sketch nature with unlimited amount of virtual paper and ink.
24  Screen Tablet malarky / Build Logs / Re: Unneeded-IQ on: June 28, 2017, 07:29:13 PM
Oops. I forgot about frequency. I build similar oscillator and notice significant frequency error at 10khz. At 100khz circuit are unstable and way off from simulation. For 1kHz You may expect less than 10% error at frequency. Sorry for scare You.

More important thing: LM358 aren't rail-to-rail amplifier. I expect non-linear distortions near minimum and maximum settings - may be noticeable but not critical.
25  Screen Tablet malarky / Build Logs / Re: Unneeded-IQ on: June 27, 2017, 07:06:59 PM
Fingers crossed Smiley

btw, LM358 have very poor performance. Oscillator with this chip will always run slower than with modern op-amp. You may need to tweak values before get it working.
26  Screen Tablet malarky / Heyaaaalpppp / Re: eDP controllers on: June 27, 2017, 06:51:38 PM
As far as I know, eDP digital interface is almost identical to DP port. Major differences are:
- different cables and connectors,
- eDP must provide power for crystals (LCD) and LEDs (backlight) while DP only sources video,
- flat panel need control interface for backlight power (different sources describe this as extra wires or embedded protocol) while tegular monitor may be controlled by buttons or PC (depend on implemented features).
27  Screen Tablet malarky / Build Logs / Re: Unneeded-IQ on: June 23, 2017, 09:30:44 PM
I looked at monitor documentation once again. Schematics are for main PCB. This board have analog RGB input only.
There are also second PCB called power board and contain input connectors. If DVI->VGA converter exist, there must be chip for that job. If You cannot found converter chip (min. 20 pins) on power board, this monitor have only DVI-A input.

I'm 100% sure that dimming are realized by PWM output. No one use DAC for analog output. There are only two options: PWM or analog via PWM + resistor + capacitor.
Look at PDF, page 38, top left corner. There are a lot of signals. Somewhere in the middle You can found DIM-ADJ (7) signal. It's connected to two resistors and capacitor.
IMHO You should use DIY analog->PWM converter. Yes, You can get PWM signal by removing capacitor or by connecting directly to chip (left side od R61 ? ). But there are second problem, PWM frequency. LED driver have limited frequency capacity (often above 100hz, rarely above 1khz). On the other hand monitor chip can easily produce PWM signal with range 4khz - 45khz, depend on selected options.
28  Screen Tablet malarky / Build Logs / Re: Unneeded-IQ on: June 22, 2017, 06:30:00 PM
DVI input:
I checked schematic and cannot found digital input. Looks like main electronic board have only VGA input. I'm not sure whet to say about DVI->VGA converter but I'm sure that it doesn't exist on schematic.

Inverter voltages:
Most CCFL drivers works from 3.3V to 12V. If higher supply voltage is essential, controller may be powered from "enable" line or from main input through resistor and zener (simple voltage stabilizer). First solution is common in laptop designs. In Your case I'm sure that 24V goes only to CCFL transformer and power transistors. 5V goes to driver chip.

Inverter pinout:
look at page 40 (of 41). Inverter need single 5V line. Second one are PWM  Cool
29  Screen Tablet malarky / Heyaaaalpppp / Re: Laptop screen to wacom cintiqfor drawing on: June 17, 2017, 06:43:47 PM
Real aluminium tape may cause short circuit and destroy Wacom. I prefer to use different type of tape especially "duck tape" - plastic thing but reinforced.

Front cover have two aspects. First is base material. Glass may be fragile but 2mm layer should be enough for drawing. Plexi are elastic and may bend enough to put pressure to LCD surface but it's easier to cut. 3mm may be enough but I'm not sure. Second thing are just top layer. This layer determines scratch resistance, dirt resistance and friction for pen.
I recommend You to use glass and put protective sticker on top - to reduce pen friction. But again I have only experience based on two tablet-PC screens and few things that I try to put on top of it to cover deep scratches. Based on my experience, scratched surface of tablet screen are the best thing I can found. Bare glass and few plastic things have much higher friction than original tablet surface. So You need to test it all on Your own.
30  Screen Tablet malarky / Heyaaaalpppp / Re: Laptop screen to wacom cintiqfor drawing on: June 17, 2017, 04:36:17 PM
I looked one more time at Your photos and noticed that You have strange type of screen.
Normal screen are designed to have small frame but great thickness. That type have PCB folded behind screen.
You have different type of screen designed to be thin but much bigger than active area. You already have PCB located at side of screen and not need to straight the flexible connectors.
I not have experience with that type of screen and cannot help You this time. Sorry.

LCD panel doesn't generate as much heat as You think. That amount of heat cannot burn electronic components inside screen or tablet. Yes You can stack screen on top of Wacom and don't worry about Wacom. There are only two components extra sensitive to heat: liquid crystals inside display and LEDs.
LEDs have designed live time about 30k hours at 30*C (data for regular LED, backlight strip may have different parameters) but live time will drop significantly as temperature increases. To reduce temperature You can keep part of frame near backlight strip or reduce backlight power by PWM dimming (if supported by HDMI converter).
Liquid crystals will refuse to work above certain temperature. As result image will disappear, but reappear when you cooled the screen. If You see that effect at edge of LCD - You almost killed LED backlight.
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