External keyboard with a kindle

[geekmaster]

Originally Posted by yifanlu

Why all this talk about a serial port? Who wants to walk around with a half opened kindle all the time?

I think that the point of this thread was to use the kindle as a small low-power standalone computer with sunlight-readable display. The Kindle 3 is best suited to use with a serial device because it has the serial port and power available in the left slots where they can be used without removing the cover.

Using the kindle external USB port with a USB host bridge device was also discussed as a way to attach external devices to the kindle.

A kindle with wifi can also use wifi-enabled devices such as wifi webcams, wifi printers, and wifi remote-control toys and devices.

Another solution is to add a bluetooth serial adapter inside the kindle, as was done long ago on a kindle 2, but this requires opening the kindle at least once, and finding a way to shoehorn it in there (if even possible on newer more compact kindles).

Not everybody is ready to port android to their kindle (at least not yet). Personally, adding an onscreen terminal console with touchscreen keyboard to the diagnostic partition of my touch is attracting my interest. I decided that /mnt/mmc is a good place to keep the "other" root partition mounted in both main and diag modes (during development and testing).

Everybody has their own interests and their own areas of expertise. Some people are interested in attaching a keyboard to their kindle, and other people think it is a dumb idea. To each his own, as they say.

[yifanlu]

I thought we are talking about the kindle without keyboard. If not, what's wrong with the built in keyboard? What does OP want to do with this "kindle computer"? Most of the time, it's easier to solve the main problem than to solve the problem created by a solution to the main problem.

[geekmaster]

The original poster did not say WHY he wants to add a *real* keyboard to a "kindle (or other e-ink device)". From MY point of view, it is rather hard to touch-type on built-in kindle keyboards (including the older keyboards with "chicklet keys" and the new K4NT and KT "onscreen keyboards").

Personally, I think that the kindle eInk display with a folding keyboard would be a great device for writers on the go, especially in an outdoor environment (such as sitting at a picnic table). A Kindle 3G and a folding serial keyboard both fit in a handbag or a large jacket pocket. You do not need much computing power to compose text, and the kindle contains enough storage to hold a LOT of text. Readability, portability, battery longevity, and ease-of-use are primary concerns in this case, and a kindle with a foldable keyboard certainly fits all of those categories quite nicely.

There is not yet a standard off-the-shelf device with a useful keyboard, sunlight readable display, and long battery life (that I am aware of, at such an affordable price), so hacks such as requested by the original poster are desirable to satisfy such a desire. A kindle with full-size tactile-feedback keyboard such as the surplus foldable serial keyboards from PDAs would certainly fill that need, and I want one too. That is EXACTLY why I bought some cheap keyboards off ebay awhile back (for about $5 each including shipping).

@yifanlu: I have seen your old "what's the point?" posts about adding keyboards to kindles when this topic came up in the past. Why does it bother you? I do not think I could come up with a satisfactory reason to convince you when your mind is already made up. Is "because I want it" a good enough answer? (P.S. I very much respect all your non-keyboard posts that I have read so far, but I disagree with your opinion of using external keyboards and mice with kindles. I am thankful that my Kindle 3 has an easily accessible serial port, which is one reason why I have three of them, and serial mice and serial keyboards too. I have written more than a MILLION lines of code in my life, and it would have been nice to have done more of that out in the fresh air and sunshine.)

[geekmaster]

To get foldable serial keyboards for about $5 shipped, I used "BayGenie eBay Auction Sniper Free Edition". If you start bidding too soon, you can start a bidding war. Just sayin' ...

[DustyDisks]

As far as I have seen, on the kindle 3 serial port plug yes there is the picture, but no real size dimensions and on how big in size in mm or inches. The spec's of the roll your own plug would be greatly appreciated. Maybe they have been posted, but I have yet to find them. Yes I could take one of my micrometers and do it the hard way!

But lazy is what is what lazy does...

[RV987789]

Well, I want to clarify some things.
Ideally it would be best to have a Kindle to which you attach an external keyboard with a power supply and all was done that already.

However, if that is not possible without some skill and with the right materials (adapters, such as regulating the voltage for the keyboard, etc..) Then I think an alternative would also use an external keyboard to control the kindle with a phone or a laptop as an intermediary.

Why I want this? The answer is simple: I need
1) a quick way to insert text (a qwerty keyboard) in
2) a non-glossy screen.

EDIT:

The first option is understandable because the Kindle's keyboard or mini keyboards qwertys of e.g. blackberrys are NOT good for inserting text quickly.

The second option is important not only because the electronic ink display to work outdoors (which is already a lot) but because the electronic ink display does not hurt the eyes.

[geekmaster]

I do not think that the existing K3 keyboard plug (I think Seaniko7 was making some cables), does not take enabling power into account. The bottom slot has four pins. The bottom two pins need to be shorted together to enable power to the top slot.

To supply power to external devices, the K3 needs something plugged into both slots on the left side.

Ordinary PCB material is too thick and needs to be made thinner to fit the kindle slots.

Another way may be to get some copper foil tape from a craft supply store and stock small pieces of copper tape on thin plastic such as from an old credit card. You know, the "hacker" way.

You could find out where you need to cut by sticking fresh shiny copper on a card into the slot, and see where the pins leave scracthes or dents on the copper, the separate those traces. You can solder to copper foil.

A agree about the eInk display being kind on the eyes (especially outdoors). I also agree that typing on a "full-size" QWERTY keyboard is much faster than on tiny chicklet-style or onscreen keyboards.

I believe that you can get "real work" done on the K3 plus external keyboard combination. I look forward to working outside in the sunlight with no eye strain next summer.

[geekmaster]

Here is the schematic for a level-shifter circuit that can connect a 5v or 3.3v TTL serial device to the kindle 1.8v TTL serial port:

https://www.mobileread.com/forums/sho....php?p=1897643

I tested this with a 3.3v USB TTL serial adaper (which needed to be modified by removing a status LED from its RxD pin).

[RV987789]

So, finally I purchased an alphasmart dana. Maybe its not the best alternative but is the closer alternative for my needs. I will talk about my experience when it arrives!
Anyway, I will wait for the easiest way to connect an external keyboard to the kindle...

[RV987789]

I would also like to thank geekmaster because it has been more specifically the person who has raised an alternative. Unfortunately, such solutions are not available to me.

[geekmaster]

Hmm... an Alphasmart Dana is actually a full palm-compatible computer with keyboard?

You would need to run a palm terminal program on it to connect it to a kindle.

It runs palmOS 4.1 so there should be a lot of software you can install on it. There *must* be a serial terminal program you can run on it.

[jbefumo]

Not exactly keyboard related, but probably similar issues . . .

I've mounted my Kindle (wifi) to a microphone stand, and use it as a less obtrusive replacement for my old binder full of lyric/chord charts when performing live. What I'd like to do is build a foot controller with two momentary switches for flipping pages while my hands are occupied with the guitar. Is this something that could conceivably be done using the external USB port on the Kindle? I'm not a stranger to soldering irons, but most of my experience is with big hollow-state (tube) circuits, and since the Kindle was a gift, I'd prefer not to risk destroying it.

Thanks!

Joe

[geekmaster]

You need a USB host bridge device, such as a small microcontroller with USB host mode. The kindle will see it as a host PC. It can tunnel any kind of traffic over the USB connection between the kindle and the I/O pins provided by the microcontroller.

Up until recently, USB host mode was complex and usually needed a special USB chip to support it, but recently a full USB host mode software stack (LUFA) for embedded devices was open-sourced and has been ported to ARM and AVR devices.

LUFA USB host stack home page:
http://www.fourwalledcubicle.com/LUFA.php

AVR port of LUFA USB host stack:
http://winavr.sourceforge.net/

An AVR LUFA device:
http://hackaday.com/2011/07/30/avr-p...kii-uses-lufa/

Another option is the Kindle 3, which has an external serial port that could easily be connected to almost any little embedded processor (such as the $4.30) TI 4-3-Oh device.

[jbefumo]

Thanks much for the pointer! I think I should be able to make that happen 8^)

Originally Posted by geekmaster

You need a USB host bridge device, such as a small microcontroller with USB host mode. The kindle will see it as a host PC. It can tunnel any kind of traffic over the USB connection between the kindle and the I/O pins provided by the microcontroller.

Up until recently, USB host mode was complex and usually needed a special USB chip to support it, but recently a full USB host mode software stack (LUFA) for embedded devices was open-sourced and has been ported to ARM and AVR devices:
http://www.fourwalledcubicle.com/LUFA.php

An AVR LUFA device:
http://hackaday.com/2011/07/30/avr-p...kii-uses-lufa/

Another option is the Kindle 3, which has an external serial port that could easily be connected to almost any little embedded processor (such as the $4.30) TI 4-3-Oh device.

[geekmaster]

Another option that would work with any wifi-enabled kindle is a wifi foot switch. You might use an OpenWrt router for such a thing, and use the router to tunnel your switch over wifi SSH to any Kindle wifi-connected to it.

You can connect your foot switch across one of the internal switches in the router.

You can also connect across the LEDs that you can control from software, to use as output connections, like I did for the SD card interface shown in the above link.

No need to use that router though. There are many hackable wifi devices and USB devices that could be bent into submission and forced to do your bidding.

The kindle can also support wifi host mode so it can act as a wifi hotspot with appropriate software. A wifi footpedal could connect directly to the kindle with just a wifi client such as the one built into this SD card:
http://en.wikipedia.org/wiki/Eye-Fi

It all depends on how much time and/or money you want to spend on implementing this custom hardware and/or software. Who knows -- perhaps there is an off-the-shelf wifi footpedal you can buy already? If not, somebody could make some money manufacturing them (until the Chinese come out with a cheap clone that sells for much less than the cost of your parts, including shipping).

Originally Posted by jbefumo

I've mounted my Kindle (wifi) to a microphone stand, and use it as a less obtrusive replacement for my old binder full of lyric/chord charts when performing live.
...

I hear that the Kindle DX Graphite with its larger 9.7 inch screen is quite popular with musicians for displaying sheet music.