Follow along as I detail the next stage of ‘humble hacking’ the Kinesis Contoured keyboard — replacing the controller board with a hand built prototype board.
Step 1 – Strip the main board
The first step is to remove the main board from the keyboard, and strip off all the components that need to be reused. This is mainly the edge connectors and the LEDs. I stripped the entire board to make it easier to follow the traces, but you shouldn’t need to go that far if you use the tables from the previous post.
Step 2 – Mount the location critical components
For the replacement controller board, I’m starting with a prototyping perf-board. It has holes with standard 2.54mm spacing, and solder pads on one side. First, I cut the board down to size, then I drilled the necessary mounting holes and cut slots for the two alignment tabs. Finally, I mounted the LEDs and the four edge connectors.
Old vs. New – solder side
Old vs. New – component side
Step 3 – Test fit the new controller board
Once all the location critical components have been attached, I installed the board to make sure that everything was going to fit.
Step 4 – Wiring
This step is the most tedious and time-consuming. Basically, you’re just connecting pins on the MCU to pins on the various edge connectors and LEDs. But there are a lot of those connections to make. In the images below, you can see the sheet I printed out to help me make these connections. The edge connectors are in the ‘Connections’ column on each table, while the MCU pins are written in pencil to the left of each row.
To keep the wiring from becoming a rat’s nest, I threaded the wires through the holes and tried to maintain right angles. The wire is very fine 30 gauge ‘Kynar’ wire.
Note that I used a Sharpie to label the edge connectors. This turned out to be a big help, but it’s very important to make sure that they are labeled correctly. The first time I wired this up, I confused myself as to which side was up, and labeled the board exactly backward. If you’re following this closely, please don’t label your board like the two images below, or you’ll end up like me and have to rip it apart and start from scratch!
Not shown in these images is the connection of the two thumb boards.
Step 5 – Mount the board
Almost there! Once the board is complete, place the board, reattach the four individual keyboards, and screw everything down.
You may notice that I had to trim a bit of excess board to make room for the thumb boards.
Step 6 – Mount the external USB-B connector
Finally, we attach the USB mini-B to USB-B adaptor cable to the original cable exit hole on the bottom case. This involves drilling two holes and mounting the adaptor with two screws and nuts.
Once the adaptor is mounted, we just plug it in to the mini-B connector on the Teensy++, and close the case!
Next up: programming the Kinesis Contoured keyboard with the humble hacker firmware.