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Author Topic: TabletPC Quickkeys  (Read 19418 times)
tpope
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« Reply #30 on: February 25, 2011, 08:54:50 PM »

Id like to applaud your cleverness in this keyboard hack. I don't think I'd have had the patience to figure out the terminal bridging sequences for the keys.

I missed this before, sorry.

Honestly, tracing just these five keys wasn't all that difficult.  A bit tedious, and I do think I might try a suggestion I read somewhere of scanning in the circuit and then using the fill tool in Photoshop to pick out the leads.  But even manually it wasn't bad.  Even where I screwed up the tracing (I think Alt in this one) I was only off by one lead, so playing with a bit of wire and shorting across settled that.

If I needed to trace a dozen, or the whole keyboard, I may be more tempted to make a grid map (in this case it would be 14 rows by 14 columns) just shorting every combination of leads and writing what they do, if anything, in the intersection.  The Tablet Input Panel in Windows makes this easy, since it lights up the keys you're pressing.
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bernard
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« Reply #31 on: February 26, 2011, 12:36:05 AM »

Relays are easier to think about than diodes me think!  I'll give it a thought for a second.  You can try to see if you use a diode in one direction works and does nothing in the other way than that means diodes are an option in this circuit. (if you have a spare led, you might be lucky using that for experimenting -- leds are diodes after all -- just emiting light as a bonus).

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bernard
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« Reply #32 on: February 26, 2011, 01:28:55 AM »

if a diode works to block the signal in one direction but not in the other in the case of the keyboard, then, a single diode, I think, should be enough to fix it -- just have to find the good polarity (putting it one way or the other).


* diodepatch.jpg (36.38 KB. 358x608 - viewed 482 times.)


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bernard
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« Reply #33 on: February 26, 2011, 02:31:00 AM »

So in the tradition of not buying anything: Diodes are frequent in PCBs.  You typically recognize them because they have one side with a white strip.  The non-surface-mount types are often like a black cylinder with the white strip on one side. You might find them in power supply circuits.
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Whereas the surface-mount ones have a similar white strip but in a little "rectangle box" package. Of course, surface mount is more difficult to handle and solder but more popular these days.  Diodes are still popular because of the bridge rectifier circuits (converting AC to DC), but I am not sure if these would work on the keyboard signals.

So one thing you could try is to cut the wire (where I painted black) -- (in case you didn't do that already to fix your CTRL key!!) and try to hook a diode in series there scavenged from another device. Try connecting one way and then the other. Nothing can break.
« Last Edit: February 26, 2011, 03:44:57 AM by bernard » Logged
tpope
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« Reply #34 on: February 26, 2011, 05:51:51 PM »

...
So one thing you could try is to cut the wire (where I painted black) -- (in case you didn't do that already to fix your CTRL key!!) and try to hook a diode in series there scavenged from another device. Try connecting one way and then the other. Nothing can break.

I had a few diodes, both through mount (is that the term?) and surface mount, already scavenged from some of the earlier demolition jobs.  Most of them look like the glass ones in the image you posted.  So I took a random one, no clue what the rating was (I can hardly read the numbers on the side and don't know what they mean anyway) and wired it in as you described.

It... just... worked!  First time.  Perfectly!

By the time I finished writing my last post, I had completely talked myself out of using a diode, I just figured I was being naive and clueless.  I was all set to go with "good enough" and just clip the wire this time. So thank you, very much, for the mini diode tutorial and encouragement!

After adding some shrink tubing to either side of the connection with the diode, I glued on the frontplate.  It'll take about a day to dry completely, so by tomorrow I will hopefully be using Mk2 to start designing Mk3. :-)


* quickkeys-mk2-diode.jpg (80.51 KB, 500x588 - viewed 507 times.)
« Last Edit: February 26, 2011, 06:54:09 PM by tpope » Logged
tpope
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« Reply #35 on: February 28, 2011, 05:56:51 PM »

Well, the glue is dry and I've had a day to play around with Mk2, as well as use it seriously for a few things.  I've decided, like Mk1, not to bother with capping any of the sides.  The wires are all protected well enough that I'm not too worried about them, and cosmetically, I kind of like the MacGyver look anyway.  :-)

One drawback of using scavenged buttons from so many sources is that, even when they look identical, there are at least two different styles in here, and you can feel it in the subtle differences in how easy it is to click them.

I also am not totally pleased with the plastic sheeting I used.  At the corners it's stuck in places to the glue, and that makes in particular the control-z key a bit harder to press than the others.  It's also just rigid enough that if I'm not careful I can sometimes accidentally trip the Alt key when I press Shift.  Though that also may be due to the fact that I think the shift key is one of the ones that got a stiffer button.

Also, it's not perfectly sturdy, given the connection point.  Now, in regular use that's not a problem, as it's not load bearing and I would have a reason to not hold onto the back of the device while I push the buttons.  But I almost had a broken device (or worse, broken USB port) when my 6-year old rambunctious son was climbing all over the bed not watching where he was going.  Sadly I'm not sure there's much of a solution to that, other than "be careful."  I've pretty much come to the conclusion that moving the buttons up onto the bezel of the tablet is just too uncomfortable to use, and that would also add 6mm to the overall height of the device.

If I wanted to make this unique the the LE1700 and worthless on other tablets, I still have the option of the double USB port, or a lip onto the bezel to make it sturdier.  I'm certainly going to consider those options when I work on Mk3, though at the moment I'm not seeing either as all that viable.

Overall though, I'm very pleased how this is working.  It's incredibly useful and makes my tablet a lot more functional when I'm doing more serious work than sketching, and it's just so pleasing to have built something like this myself.  While all of the complaints above are valid, none of them detract significantly from the value of the device for me.  It's sturdy enough, comfortable enough and usable enough that I could very well stop here with no regrets.

But I'm not going to stop here.  For one, there are still refinements I could make, and for another, I have a friend with a LE1700 and I really want to make one for him as well.  So I think the next step is first to find two (at least) identical keyboards, and then start to seriously design a full kit in lasercut plexiglass.  This I imagine will be even slower going than Mk2, and will of course involve spending some actual money, so I'm going to be a lot more careful in measuring and templating (probably in cardstock) before I buy anything.  But it's doable, and I think the process will be a good learning experience. 

Thanks to all who've replied for the advice and encouragement.  Reading this forum (and not just conversations in this thread, but all of the other build logs) has been a great source of inspiration.  I'm actually feeling a lot more confident now about my ability (someday) to take the next step and build a DIY Cintiq of my own.  ...probably with a custom button bar.  :-)




* quickkeys-mk2-finished.jpg (146.4 KB, 800x608 - viewed 806 times.)
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bernard
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« Reply #36 on: March 01, 2011, 04:16:32 AM »

Hey!!  that's very cool!  -- Using a diode was the best thing to do afterall! You've got a very good intuition there.  "Through hole" (not sure about the spelling, maybe thru-hole) is how I am used to call the non-surface-mount parts.

The "glass" diodes ones are also very popular indeed. For the "specs" all the "small" ones should have worked because their spec is more like how much voltage they can take or their "reverse breakdown voltage", their "basic" operation is pretty standard.

Laser-cut:  watch out that "laser cut" does not equates "it works" -- far from it -- one reason is that you do not have the material in your hands (not all plastics are the same) and you are not "cutting/sculpting it" yourself with a "try-it & refine-it" tight loop. Unless you already made a working prototype, you will probably need a couple of rounds before getting the thing right. (But you might get lucky or just deeply know how to work with tolerances to not miss it).  It is quite cool to design a complex shape and get it in your hands for real. Besides you seem to like to do these things, so that will be an invaluable experience.

Ruggedness:  the LE1700 is a rugged-tablet-pc -- so I am thinking maybe there is already spots/holes to put some sort of "bracket" that would be sturdy. I mean some sort of metallic bracket that would go into "holes on both sides of the laptop" (if there's such a thing).  I see they sell some accesories like a keyboard that also doubles as some sort of "docking station".  Anyway, just a thought.

The LE1700 uses a Wacom driver -- so I assume this is a wacom sensor -- is this a "Penenabled"?  I guess my question is: are you getting the pen pressure data?
« Last Edit: March 01, 2011, 04:21:59 AM by bernard » Logged
tpope
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« Reply #37 on: March 01, 2011, 10:27:16 PM »

Hey!!  that's very cool!  -- Using a diode was the best thing to do afterall! You've got a very good intuition there.

Yeah, I really lucked out on that one.  I also just found a work discard (out of a laser printer IIRC) with dozens of regular and zenier diodes (mostly of the glass variety) so I'm well stocked.

Quote
The "glass" diodes ones are also very popular indeed. For the "specs" all the "small" ones should have worked because their spec is more like how much voltage they can take or their "reverse breakdown voltage", their "basic" operation is pretty standard.

Good to know, thanks.  I've got a lot of them now, some zenier, some regular, some regular with yellow stripes and a few oddballs here and there.  It'll likely be trial and error next time, but at least I know what effect I'm looking for.

Quote
Laser-cut:  watch out that "laser cut" does not equates "it works" -- far from it -- one reason is that you do not have the material in your hands (not all plastics are the same) and you are not "cutting/sculpting it" yourself with a "try-it & refine-it" tight loop. Unless you already made a working prototype, you will probably need a couple of rounds before getting the thing right. (But you might get lucky or just deeply know how to work with tolerances to not miss it).  It is quite cool to design a complex shape and get it in your hands for real. Besides you seem to like to do these things, so that will be an invaluable experience.

All agreed.  My plan right now is frequent testing with cardstock mockups, careful measurement where material thickness comes into play and a bit of luck.  Ponoko has a limited selection of acrylic in the thicknesses I want, but I figure that if I end up making minor mistakes (the kind not caught by cardboard mockups) I still have the dremel to try and fix them, rather than wasting the whole pattern.  We'll see what happens.  I have two more Dell keyboards at the moment, though they are not the same model.  At a guess, one will be similar to Mk1 and the other similar to Mk2 in terms of PCB size and layout, but I won't know until I strip them. 

Quote
Ruggedness:  the LE1700 is a rugged-tablet-pc -- so I am thinking maybe there is already spots/holes to put some sort of "bracket" that would be sturdy. I mean some sort of metallic bracket that would go into "holes on both sides of the laptop" (if there's such a thing).  I see they sell some accesories like a keyboard that also doubles as some sort of "docking station".  Anyway, just a thought.

There is a docking station and a clip-on keyboard, both of which use metal kingposts that fit into metal lined holes in the frame.  The problem is that they attach to the bottom of the tablet (in landscape mode) or the right side (in portrait mode), neither of which is convenient for a right-handed pen user.  There are even programmable buttons and a d-pad on the LE1700 (it is, by far, the best artist slate on the market today, despite being 4 years old) but they end up on the top or right. 

If I could find a few spare free (instead of $50 and up) LE1700 keyboards I might be tempted to try hacking one of them anyway, and just find a 3rd party video driver to let me rotate the 270 degrees to place it on the left.  It would have the advantage of being usable in portrait mode.  An interesting thought certainly, but I think not worth the destruction of my only keyboard right now.

Quote
The LE1700 uses a Wacom driver -- so I assume this is a wacom sensor -- is this a "Penenabled"?  I guess my question is: are you getting the pen pressure data?

It is penabled, like other TabletPCs.   ...and yes, with the Wacom driver I get full pressure sensitivity across all applications.  It's really a nice machine overall.
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bernard
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« Reply #38 on: March 17, 2011, 05:20:33 PM »

I am going to interface penenabled tabletPC sensor boards -- the serial-based ones -- and convert them to appear as USB Wacom device.  I am looking for the pinouts of the different models.  In all your laptop ripping, have you encountered such sensor? 

(Well, I know you have a tablet pc -- but a functional one, I am not asking that you risk-open it for me -- but it would be very cool that you do so if you can put a multimeter on the running device Smiley )

If you have any info regarding Penenabled boards -- I would like to "list" the models that are out there and know a bit more about them. (and which sensor is inside which laptop, etc.)
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tpope
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« Reply #39 on: March 17, 2011, 10:03:47 PM »

I am going to interface penenabled tabletPC sensor boards -- the serial-based ones -- and convert them to appear as USB Wacom device.  I am looking for the pinouts of the different models.  In all your laptop ripping, have you encountered such sensor?  

(Well, I know you have a tablet pc -- but a functional one, I am not asking that you risk-open it for me -- but it would be very cool that you do so if you can put a multimeter on the running device Smiley )

If you have any info regarding Penenabled boards -- I would like to "list" the models that are out there and know a bit more about them. (and which sensor is inside which laptop, etc.)

I've only torn apart one so far, a Thinkpad X40T (I believe, it was a while ago).  The tablet part is right here pinned to my "wall of electronic bits" so I'll take a few photos...  

Here is the full board (front side, backside is totally covered by a red metallic film, shielding probably.  The digitizer itself (leaving aside protuberances) is 10.125" by 7.625" roughly, and fit behind a standard 12" LCD.  I tossed the LCD when I found that I couldn't drive it (wrong connector) from my NJYTouch controller.  It's also honestly smaller than I wanted to bother with even if I could have gotten it working.

* penabled-x40t-overview.jpg (92.82 KB. 800x600 - viewed 464 times.)


Here is the PCB itself.  As you can see, it's a 14 pin connector back to the computer, but that's all I could tell you about it.  There is nothing useful on the back but circuit traces.  No printing or pinout definitions or anything like that.

* penabled-x40t-pcb.jpg (195.25 KB. 1024x768 - viewed 508 times.)


...and here is the back label with all of the various part numbers (the most important probably is the Wacom SU-040-X01)

* penabled-x40t-label.jpg (75.52 KB. 640x480 - viewed 505 times.)


While I'm not opposed to running some current through this (somehow) and testing leads with a multimeter (again, somehow) I also don't have any idea where to start on something like that.  I mean, I could easily get a +5V signal from a random USB cable but I wouldn't know where to try and wire that and the ground, nor what I'd be looking for on the other pins.

Sadly, when I pulled this apart, I wasn't really thinking about getting it work again myself, or I would have at least cut off the cable at the connector to make testing easier.


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bernard
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« Reply #40 on: March 18, 2011, 01:32:56 AM »

thanks tpope for pulling it out.

SU-040-X01 --- darn!  yet another wacom model number not in my little list.  They have a *lot* of different models, it is crazy!! http://wiki.bongofish.co.uk/doku.php?id=bongofish:penenabled  I will add this model.  Could you measure the "active area" (or the "apparent" active area), thanks.  You said 12 inch lcd -- Would you know if that is 12.0 inches or more?  I assume that is not a wide screen aspect ratio, right?

14 pin seems like a recurring theme at least.  Well -- apart from **mine** which is 10 pins (sadly).

I think the 10pins are UART (serial) only and the 14 pins are UART & USB -- but that is a theory only.
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bernard
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« Reply #41 on: March 18, 2011, 03:17:45 AM »

As I saw from another board, a big Zener diode (and a resistor next to it) is not installed. That would indicate that this board is powered by a 3.3v --  the Zener diode + resistor is often used to regulate power (going down in voltage -- like going from 5v to 3.3v essentially).  That does not necessarily mean it was not using the USB signals, (since USB comes with 5v power supply) -- but it probably means it did not take its power from the USB -- which is probably quite normal given that it is an internal device.
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tpope
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« Reply #42 on: March 18, 2011, 07:01:56 PM »

thanks tpope for pulling it out.

SU-040-X01 --- darn!  yet another wacom model number not in my little list.  They have a *lot* of different models, it is crazy!! http://wiki.bongofish.co.uk/doku.php?id=bongofish:penenabled  I will add this model.  Could you measure the "active area" (or the "apparent" active area), thanks.  You said 12 inch lcd -- Would you know if that is 12.0 inches or more?  I assume that is not a wide screen aspect ratio, right?

It's hard to tell from the wires on the sensor board, but I do know the effective active area is pretty close to exactly 12" and that the sensor board fit exactly under the LCD, if you include the LCD bezel in the measurements.  Not widescreen, but the standard 12" XGA netbook/tablet display of that era.  In fact, it looks like the dimensions were the same as on my LE1700.
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bernard
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« Reply #43 on: March 18, 2011, 07:09:34 PM »

Ok, so XGA would mean it has 4:3 aspect ratio.
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