Introduction: Installing a USB Keyboard Into an OLPC XO Laptop, Phase I
I don't know about you, but I can sure tell silicone from the real thing. Here's how to ditch the jelly and squeeze a normal keycaps-and-springs type USB keyboard into an OLPC XO laptop. This is "phase I" -- getting the keyboard into the lower half of the case, but leaving the USB cable connected to the external USB port (UPDATE: Phase II instructable now posted).
Radical surgery to the lower half of the XO is necessary, so your OLPC will never be the same if you do this. I did it because I had too many Dremel wheels on my hands and my XO was so much more convenient to cut holes in than my neighbor's car. Who wants to mess with an extension cord and the potential for bad weather? Also because my XO's keyboard failed -- the Ctrl key got stuck -- after the 30 day warranty period had already ended.
Things you'll need:
1. A new keyboard (see step 1)
2. Dremel tool or equivalent in sweat and pain
3. A jeweler's large phillips screwdriver, or one of those double-ended freebies they used to give away at IT-related conventions
4. Lots of cellophane tape (or hundreds of tiny helpers who don't mind being sealed inside your XO forever)
5. A desoldering iron (optional)
6. An XO laptop from OLPC, preferably one that has a keyboard problem.
Step 1: Order Your New Keyboard
You kinda hafta order the keyboard first. Otherwise, you'll take apart your XO, and the pile of parts will slowly eat into your subconscious mind with subliminal nagging: "I used to be a laptop," and "You never finish anything," and eventually "Please...kill...me..." Maybe it's just my projects that say things like that.
The "Super Mini USB Keyboard" at CyberGuys.com sounded like a match based on the advertised measurements. When the box arrived in the mail, the package declared it to be an "ASK-3100 Series Ultra Mini Keyboard," featuring "the architecture of scissors keycaps."
I'm no architect, but the ASK-3100 Series Ultra Mini is a near perfect fit and a pretty good deal at $32 (plus shipping). I neglected to sign up for the "buyer's club" to get the extra 5% off. Sign up for the extra 5% off!
Here's the URL: http://www.cyberguys.com/templates/SearchDetail.asp?productID=7599
Step 2: Shucking the Keyboard
It's time to take the case off of the ASK-3100 Series Ultra Mini Keyboard. There are eight screws on the bottom of the keyboard, but three of them are hiding from your screwdriver. Two of these cowardly screws are below the rubber feet to the front of the keyboard; peel the feet off with your thumbnail or a pointy stick. The other one is behind a sticker marked "DO NOT REMOVE." You know what to do.
Once you have the shell off, you need to disconnect the ribbon cable between the keyboard and its controller card. But wait! Unless you can design original origami figures in your head, you should take a pen and mark both the cable and the connector with an asymmetrical symbol, like the letter "F," right where they meet up. That will help you later when you have to put them back together the same way they started out. The small circuit board with the caps lock, num lock, and scroll lock LEDs on it is the controller card. The ribbon cable is about to have a bad day, so pull it gently straight back from the connector.
Step 3: No Disassemble? Yes! Disassemble!
I am going to have to assume some things in order to get to the heart of the project at hand.
1. You can read.
2. You can browse wiki.laptop.org.
Assuming 1. and 2., you should be able to go to http://wiki.laptop.org/go/Disassembly and read the detailed and complete instructions on taking apart your XO. For Phase I of this project, you don't need to take the top half of your XO apart, just the keyboard part. When you're done getting everything apart, you'll have an XO "head" dangling two cables. The head will still works on AC power, as shown in the first photo, but the bottom part pretty much does nothing at this point.
Here I am making sure that the keyboard works. I forgot to do that before I voided its warranty, but luckily it has no problems.
Step 4: Nothing Irreversible Yet
Assuming you didn't break any of your laptop parts trying to get it apart, this next step will be the first real damage to your XO. If you stop now and put your XO back together, your dog will not think less of you, but some of us primates might make hooting noises generally associated with derision. Go pet your dog, you'll feel better.
Make sure the original keyboard's ribbon cable is detached from its circuitboard, and here we go: work your fingernail (or pointy stick) under all three layers of the keyboard, then peel it back. It should come up in a single sheet, leaving only a sticky residue on the otherwise bare steel skeleton of your XO. I did mine while the bodiless head of my XO looked on in horror. Muahaha. Ha ha. Ha.
Place the new keyboard where the old one went. You'll notice the ribbon cable is almost in the right spot to pass through the same slot as the original keyboard's did -- but not quite.
Step 5: Make a Hole
Where were we? Oh, right; making a hole for the cable to go through.
Maybe it wasn't the best choice, but I decided to simply widen the existing cable slot by joining it with the neighboring hole. That hole turns out to be where the hook-shaped pegs under the touchpad latch on, so following my example may leave your touchpad area slightly bowed (see last photo).
Out comes the Dremel tool, and at 15k RPM, the cuts are made fast. Did you remember your safety glasses? You might want a face mask, too, if you like your lungs. Either way, keep things like your eyeballs out of the way of the sparks; if the disk breaks or it kicks out something more than pretty lights, you really don't want to risk your sight.
You'll also need to make the ribbon cable a little less bulky; cut away the excess clear plastic behind the bend in the conductors. Don't cut through any of the shiny wires! After you give the cable a better elbow shape, you might want to reinforce the deepest part of the cut with some cellophane tape to keep it from tearing. Even your dog will laugh if you have to buy another $30 keyboard because you tore a few conductors in the ribbon cable.
Finally, switch to your burr bit on your Dremel and nibble away at the post that was supposed to go through that hole where your ribbon cable is now. Otherwise, bad things could happen when you put the case back together. You really don't need to reinvent punched tape as part of this project. You'll also want to get rid of the black plastic loop at the top of the keyboard, to allow the white plastic post above the keyboard to fit into its assigned hole.
Step 6: Keyboard Controller With All the Trimmings
You'll need to trim down the new keyboard controller. I could amuse you for seconds with tales of the myriad ways I sought to fit the controller into the XO's case without doing these things, but while it might gladden your heart, it would surely bring me to tears, so let's skip it.
You'll certainly need to get rid of the LED indicator lights on the controller; they're too tall. I went to the trouble of desoldering them, but you could probably just take a pair of wire cutters and snip through them. You might also be able to de-solder and move the components on the board so they're all on the same side, or shave off some of the extra PC board and connector housing. I also trimmed all the points (sharp ends of wires poking out the bottom side of the board) I could. Finally, slap something non-conductive (here I used some gun tape) over the card to prevent it from short-circuiting.
Step 7: Make a Big Scary Hole
After you've gotten your new keyboard controller down to size, the really bad stuff starts happening to your XO. The controller card was plenty skinny to fit into the quarter-inch thick keyboard case you threw away in step 2, but the XO's base is amazingly (depressingly!) thin. Don't despair, just make another hole.
This time it's going to be a keyboard-controller-sized hole in the steel plate the keyboard's sitting on. The hole will offset some of the thickness of the controller so the XO's case will actually close again. Yay.
Align the card more or less with the ribbon cable, trace around it, then cut along the dotted line. Add an extra opening for the ribbon cable so it doesn't get crunched up against the card. I used four Dremel wheels cutting mine. Hopefully you can do better. Make sure you de-burr the edges, especially around the extra space you gave the cable, so any contact it has with the steel is nice and smooth. If you want to be extra safe, cap that steel with a piece of cello tape.
Dremel away the "ribs" running along the inside of the case opposite the controller card, so that the card will have a little more room on that side, too.
Run the USB cable up and out of the case, following the trackpad controller cable, and stick everything back into place. I used plenty of cello tape. Isn't it lovely? Luckily nobody will ever see this again.
Your job is done! Call in your closing surgeon to reassemble the XO. Do remind your colleague that the stitches will have to hold extra tight, because the patient has new and bigger guts. I'd recommend feeding the USB cable around the hinge and leaving the hinge cover off for now.
Step 8: Plug It In!
Take the USB cable hanging out of the hinge of your XO and plug it into, well, your XO. Of course, you could also plug it into your friend's computer and pretend you don't know anything about the four-letter words appearing on his or her screen, and for crying out loud why can't he/she just let you work on your laptop in peace?
That's it for now. When I get a chance I'll try taking this to the next logical step; phase II will include running the USB cable into the head of the XO and connecting it to one of the USB ports directly.
February 10, 2008 UPDATE: Phase II instructable now posted: https://www.instructables.com/id/Finishing-the-Job-Installing-a-USB-Keyboard-into-/