Hacking an old Palm Keyboard.

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Re: Hacking an old Palm Keyboard.

Postby st2000 » September 29th, 2014, 11:26 am

Yes, but there's a whole Arduino/Atmel processor between the keyboard and bluetooth radio. I wanted a very small adapter that only contained a battery and bluetooth radio. The processor in the bluetooth radio is likely capable of handling the conversion between serial data and HID bluetooth keyboard. Which would make the Arduino obsolete. But I can't find any who will share how to program the bluetooth radios.

However, you do shed an interesting light on the Adafruit part. It appears the firmware has been improved:
Since version 1.1 this module can accept raw HID reports as input over its serial ... Bluefruit 1.0 will not work, and Bluefruit 1.2 is required if you would like to implement "consumer" keys (such as volume and media player controls).

And is now capable of accepting serial data. So the overhead of emulating a fake keyboard is now unnecessary. Plus the processor could be reduced to one of the smaller Atmel or PIC processors. You wouldn't even have to support the Arduino software overhead and go really really small. As the task at hand is simply to convert one serial data to another (i.e. probably doable with an 8 pin PIC processor).
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Re: Hacking an old Palm Keyboard.

Postby bijlevel » September 30th, 2014, 2:50 am

You want exactly what I want: a really small BT adapter for this keyboard without all this Arduino stuff. In my search for information (i'm still very ignorant) I have learned that a BT chipset has almost all the time an EPROM which contains (I'm only assuming this!) the keyboard matrix. If the EPROM is an EEPROM (erasable) then maybe such a chipset could be adapted to the keyboard matrix of the PPK by reprogramming this EEPROM. This should be done manually. I have found instruction on how to do this. I guess it would be a major task to reprogram such an EEPROM manually for all the individual keys, though! But maybe I'm totally on the wrong track with this and is the use for instance of a PIC a quicker and more solid solution. But I don't have any experience with either an EEPROM or a PIC.
If you love the design of this keyboard then you can also buy the BT version on Alibaba for about $ 25 (plus shipping costs to my country The Netherlands about $ 25...). Search for: P-BLUETOOTHKB025.
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Re: Hacking an old Palm Keyboard.

Postby st2000 » September 30th, 2014, 9:04 am

I usually do not like ordering from Pacific-rim sources unless I have at least 1 working sample that I have tested. Add to that, the Adafruit version explicitly states it can handle serial to bluetooth HID keyboard conversion. But only in their 1.1+ version of code. I should think it would come down to guess work to say if any one else had modules that could do the same.

I am not sure how to reprogram these devices. I am sure it is possible. But, unless you have uncovered an mess of information, it will likely be orders of magnitudes easier to program a cheap 6 pin microchip.com PIC to convert from Palm Serial to Bluetooth HID Keyborad protocol.

If you go the microchip.com PIC route, all the SDK software (editor & compilers) is free (as long as you run the code on microchip.com parts). And the SDK will run on Windows or Linux. You will have to buy (I recommend) a PICkit3 programmer/debugger. Usually less then $100. There are more expensive programmers/debuggers but 90% of the them (actually all the time for me) the PICkit3 is good enough. PICs are normally programmed in C. Some do like assembler. But the compilers are rather good these days.
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Re: Hacking an old Palm Keyboard.

Postby bijlevel » October 1st, 2014, 3:55 am

Well, considering all the lurking pitfalls, new techniques to learn, time consuming research and programming, for me (at least) this project probably is way above my head and also not worth the required investment of money e.g buying electronic parts/components, compilers, microprocessors etc. It maybe that at the end buying one with BT from "Pacific-rim sources" ;) is cheaper, assuming of course it does work for some time. The realistic risk would be that it will break rather sooner than later :) ...
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Re: Hacking an old Palm Keyboard.

Postby st2000 » October 1st, 2014, 7:54 am

It is a close thing isn't it. To buy a bluetooth keyboard or build an adapter for an existing keyboard. I am not convinced it is above your head. But if you choose to buy a bluetooth keyboard, I would recommend searching using "hp bluetooth touchpad keyboard". HP dumped their touchpad and all it's accessories over a year ago. But you might still be able to find this keyboard for a faction of it's original cost. If you find one to try - it will occur to you that it looks and feels like an apple bluetooth keyboard.

FYI: I am almost sure you can use the Adafruit bluetooth adapter running 1.1 or later firmware and an Arduino to convert the palm keyboard serial data to that of an ordinary rs232 type protocol - if that is more to your liking. The adapter would be larger than I would like but there are Arduino boards that are just about the same size as the bluetooth radio. After adding a battery you would probably be at the size of 1/2 a pack of cigarettes. Or, if you have one of the larger non-folding palm keyboards - you might be able to stuff everything inside the keyboard case.

added later...
BTW: Microchip.com does sample processors. And all the Microchip.com software you need is free (even companies don't bother buying the optimized version of the compilers - just use the free version - and never mind when it expires and turns off the optimization features). The only thing you eventually will need is the PICkit3 programmer. Which, apparently, you can buy all over the place:
http://www.microchipdirect.com
http://www.mouser.com/
http://www.newark.com
http://www.alliedelec.com/
http://www.newegg.com/
...some of the URLs were ridiculously long so I only posted the main page. Search on "pickit3". The wide range of prices is because some only offer the programmer while others offer the programmer with a development board. If you want the board great. If not - choose only the programmer. I see most sell the programmer for about $50. Newegg is the exception - their price is 1/2 as much and they claim it's origin is Asia. No doubt it is - but begs the question if microchip.com is "ok with this". Recall months ago Fluke "was not" and a bunch of mult-meters never made it to sparkfun.com. Fluke made up for it though.
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Re: Hacking an old Palm Keyboard.

Postby bijlevel » October 1st, 2014, 8:43 am

I'm not after a BT keyboard in general. I have the foldable Palm keyboard (part number 3C10439), the one for which 'camerin' (the starter of this thread) posted a link to a pdf with the technical description. I think its design is very cool, so I wanted it to use with my iPad. I still think buying one on Alibaba is cheaper then building a BT interface, but of course less fun and less educational and who knows, it might still be a future project!
Thanks anyway for all the informational links! Much appreciated!
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Re: Hacking an old Palm Keyboard.

Postby st2000 » October 1st, 2014, 9:37 am

Yes, I have the same folding keyboard. And I also have small and standard size bluetooth keyboards. I can not touch type with the small ones so if I am going to hunt-n-peck - I usually just use the screen keyboard. The large keyboard are awkward enough that I simply bring a laptop for that much typing.

If you have any success - do post back here. Reciprocating, if I ever get around to designing a PCB & programming a PIC that accepts the Adafruit bluetooth module - I'll try to remember to add a note to this thread.
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Re: Hacking an old Palm Keyboard.

Postby mclien » December 15th, 2014, 8:59 am

Hi guys,
nice to have some company on that subject. I have done some tedious work on that supject with abit of success.
(as I see quite some interest on that, give me some time to set up a project log for that. Be a bit patient, there is christmas and the 31c3 about to mangage these days).
In short I have done the following:
- I opend up the part where the PCB is hidden under
- I disconnected the spend some hours to decipher the keymatix
- disassamble the whole parts which make the stand for the PDA normally
- in the room there fits a teensy, which can emulate a keyboard
- drilled several holes into some of the plastic pieces
- cut of the part of the PCB that holds the components
- wired all the necessary pins from teensy to the connector parts of the left over PCB
- wrote a scetch with the help of the arduino forum and my son
- was able to get "some" output
This means all keys that respond where correct. But part of the layout where missing.
Main problem I guess is, that the flat PCB "cables" from the keys are stuck onto the PCB pads with a conductive tape (there is a 3M one, that is only conductive in z-Axis. Most likely i messed something up there. It apears that thereis a piece of plastic, which is intented to hold down these tape connection, what is now messing with my wire/soldering part.

So everything considered I would say best way to do this is making a custom arduino board, that works as a replacement of the original PCB an a mini USB connector. With that and perhaps exchanging the tape with a new one (I have a supply for that) should work. I hope to get into it at the 31c3 and to set up the project page before.
(pics and doku to folow)
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Re: Hacking an old Palm Keyboard.

Postby st2000 » December 15th, 2014, 7:23 pm

That, sounds like a lot of meticulous work. Isn't a lot of what you are taking apart simply glued or taped together? The Thinkoutside Palm keyboard was so thin that it reminds me a lot of how an LCD screen is mostly taped together. When you get around to it, I would be very interested in seeing what this looks like.

While taking apart the keyboard is interesting. I wanted to connect an unmodified keyboard to an Android using Bluetooth. This is feasible now if one uses a bluetooth module -and- a processor to interpret the serial data from the Thinkoutside keyboard into what the Bluetooth module expects. But I wanted to omit the extra processor and use the processor inside the Bluetooth module. But because no Bluetooth module (that I've heard of) understands Palm Keyboard serial data, this can not be done - unless we understand how to reprogram the Bluetooth module:
http://hackaday.com/2014/05/18/firmware-for-cheap-bluetooth-modules/
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Re: Hacking an old Palm Keyboard.

Postby mclien » December 16th, 2014, 8:01 am

I see. My main goal was not to need any extra boxes and such.

But speaking of bluetooth: perhaps it's possible to design a board that is capable of several things.
- USb keyboard
- perhaps even with USb passed through into the old Palm connector (for a special deiviec to be build)
- removing he holder for the Palm might leave enough room to put a LiPoly battery in there,which is chargeable via USB connector

Disassembling is quite easy BTW. It's just the "one hidden screw" trick. An there is everything in one place: the PCB which is directly attached to the keymatrix and the Palm connector. (I'll put pictures as soon as I'll manage to set up the HaD project.
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