I've been working an ADB-USB adaptor for my Apple Extended Keyboard II. You can replace either the right or left hand ADB port with this adaptor for a very clean and self-contained installation. It uses hasu's tmk firmware which should be very familiar to many people already. Here are pictures of my prototype installed:
(http://i.imgur.com/oZ2xBTp.jpg)
(http://i.imgur.com/B2QZdHM.jpg)
Taking lessons I've learned from the prototype I have revised the design to better fit in the available space. It now consists of 2 boards connected by standard headers, so that the board can be a tiny bit smaller and the USB connector will sit more in the center. This new design can be seen here:
(http://i.imgur.com/anOBdo5.png)
All the design files, schematics, and firmware for this project have been released under an open source license:
https://github.com/skullydazed/tmk_keyboard/tree/master/converter/adb_usb
(Please let me know if you find any mistakes/bugs. While the schematic is basically unchanged from my prototype the layout is almost completely new.)
What you will get if this group buy is successful
- Controller PCB Board with all SMT parts populated
- USB Connector PCB Board with SMT resistors populated
- 5 pin header
- mini-usb connector
How do I install this thing?
Installation is fairly straightforward and requires only basic soldering skill. If you have never soldered before you should practice on a kit before attempting installation, but it is nothing that you can't handle after 10 or 20 minutes of soldering practice.
Assembly
Install the mini-usb connector by inserting the ground pins through the hole. You should install only 1 connector on the side you plan to install your adaptor in. Carefully solder the SMT data pins one by one using your soldering iron and a little bit of solder. (You can use wick to sop up excess solder.) Blow on the pins to cool them once you are done, then flip the board over and solder the through hole ground pins.
Solder the header so the plastic insulator is on the component side of the controller PCB. Slide the USB board onto the header, making sure the board is oriented so that the two PCBs occupy the same footprint, and the square pads are on the same side. Solder the headers on the USB board.
Installation
Remove the top case and locate the ADB ports on either side of the keyboard. Carefully lift your chosen side straight up to remove it, and rotate it so the solder pads are facing up. Desolder all 9 pins (wick works extremely well on these joints) and remove the ADB connector. Straighten out the leads coming from the keyboard PCB.
Orient the board so that the components are facing the keyboard PCB and the header connecting the two boards is closest to the bottom of the case. Insert the 9 header pins coming from the keyboard into the 1mm headers on the adaptor. Solder them in place.
Solder two wires to the reset pad and run those out of the case somewhere. Touching these together will allow you to update the firmware.
How Much?
Price will be based on the number of orders:
- 10: $65
- 20: $50
- 30: $45
- 40: $40
- 50: $35
How Do I Sign Up?
Register your interest here: https://docs.google.com/forms/d/1x1BYzbsKiQIUECmnUlmCq-hdYQHu0cETu1eE1xHI3GI/viewform
This form will be used to judge demand and further refine pricing. You are not committing to buy anything, but respondents will have first right of refusal from the production run.
Is this only for the AEK II, or would it be possible to throw this on an AEK or Apple Standard Keyboard as well?
My guess would be that it will suit apple ADB keyboards - period, as the TMK ADB to USB converter firmware is highly customizable for a number for different apple boards!
You're both right and wrong here. As long as you can connect the wires up it can be used with any adb board. However, the AEK and ASK have different ABD ports from the AEKII and this won't fit into the same space on those, some custom wiring will be needed.
Thanks for clarifying this, I had a hunch that the case dimension would the primary concern.
Good news! I opened up the AEK and I'm 95% confident it will work without much trouble. I'll try popping one of my prototypes in later today after my daughter is awake and I can make noise.
Show Image
(http://i.imgur.com/vUDXkkv.jpg)
As you can see in that picture the ADB board on the AEK is much wider than it is on the AEKII, this is to account for the EMI filter. I'm pretty confident that with the very short distance between the keyboard and my adaptor that removing that EMI filter will not cause any problems. It won't be as easy an install as it would be in the AEKII, but it will work and with some patience can be just as clean.
Hmmm could I also create an external housing and slap it on the outside of the board just in case it doesn't fit?
An update on what I've been working on.
I've been working on a design that fits into the available space better without modifying the board or using hot glue. It will require separate boards for left and right hand side but I think that compromise is worth it. Here's what it looks like right now:
Show Image
(http://i.imgur.com/oybN7Yk.png)
Those two boards would be joined by a standard header connector and should fit within the available space. I'm going to get some card stock today and print out 1:1 scale models I can cut out to test my theory. I also need to do a bit more validation- like making sure the usb data signals are equivalent lengths.
Good progress. I had kind of forgotten about this project, but I think your redesign idea is the right choice.
BTW, I don't think equivalent trace lengths really matter. Current moves at light speed.