Kinesis thumb pcb

Kin80

Kin80 is a set of replacement PCBs and switch mounting plates for Kinesis Contoured keyboards.

It is not a drop-in replacement controllers like Stapelberg or KinT (for these controllers I developed a cheap alternative called kinBP (will be published soon)). Kin80 uses different matrix (12×7) and it is aimed at serious modding of the Kinesis keyboard.

Features

• Controller with QMK firmware support.

Uses inexpensive WeAct Studio STM32F401/STM32F411 MCU board.

The PCB has dimensions less than 100×100 mm. Many manufacturers provide additional discounts for smaller boards.

Additional pads for connecting up to 4 swithes (i.e. additional switches on the keyboard or foot pedals) and 5 free MCU pins.

• Eliminating one of the main drawbacks of Kinesis keyboards (prior to Advantage 2): rubber top row is replaced by with mechanical switches, MX or Kailh Choc.
• Replacement thumb cluster PCBs. Reversible design, additional mounting holes for compatibility with Model 110.
• Thumb cluster switch mounting plates.

Disadvantages / shortcomings

1. It's obviously more labour intensive than drop-in controller replacement. You have to desolder the key-wells and than carry out hand-wiring of new (or stock) switches. I started designing a PCB for key-wells, but came to the conclusion that flexible boards of this size are too expensive to manufacture.

2. It's necessary to carefully cut out two windows in the keyboard case with Dremel, then glue the mounting plates there. The result will most likely not look very professional. This problem can be solved by 3D printing curved plastic plates, but I don't have the skills to design them.

3. Thumb cluster PCBs require SMD diodes (SOD-323). Soldering them by hand can be tricky for unexperienced people. I'm going to add support for through-hole diodes in the next release.

4. Top row PCB have not been tested yet.

5. Other TODO's: design universal MX/Choc top row PCB, design FR4 mounting plate for the thumb cluster.

BOM

1. Controller PCB (/controller-pcb).

• WeAct Studio STM32F401 or STM32F411 board. You can buy them for about 6 USD at the official Aliexpress store. Beware of pirated copies!
• 2 pcs: 20 cm cable with 11-pin female Micro JST connectors with 1.25 mm pitch (Aliexpress) for key-wells
• 2 pcs: 10 cm cable with 7-pin female Micro JST connectors for connecting thumb clusters
• 2 pcs: cable with 7-pin female Micro JST connectors for connecting top row clusters, 10 cm if using PCBs or 20 cm if using hand-wiring.
• 2 pcs male Micro JST 11-pin angled or straight connectors
• 4 pcs male Micro JST 7-pin angled or straight connectors
• 4 pcs 3-mm LEDs
• 4 pcs 0805 or through-hole resistors. Their value depends on the type of LEDs (I use 1.5k Ohm for orange LEDs).
• Pair of USB Type C male and female connectors

2. Thumb cluster (/thumb-pcb)

• The design is reversible. So, a minimal batch of 5 PCBs will give you 2 pairs + 1 spare.
• 12 pcs SOD-323 1N4148 diodes.
• Optional: mounting plates (see /plates/thumb).
• 2 pcs male Micro JST 7-pin angled connectors

3. Top row cluster (/top-pcb)

• The PCBs are not tested yet. They also have reversible design.
• 12 pcs SOD-323 1N4148 diodes.
• PCBs are optional, you can use just plates (/plates/top) and make a hand-wiring with through-hole diodes.

4. Key-wells

• 56 pcs 1N4148 diodes
• Wire

5. ** Switches **

• 80 pcs Cherry MX compatible switches or 68 pcs MX + 12 pcs Kailh Choc
• Optional: switch opener (if you reuse the stock switches)

Buid guide

1. Disassemble the keyboard. Remove all screws and remove all PCBs. Сut the melted pins on the back plates of the top clusters.
2. Desolder the key-well PCBs. If you do not plan to use these PCBs to repair other keyboards, then you can not worry about damaging them.
3. If you plan to reuse the stock switches, then remove the diodes from them (IMHO, it will make further hand-wiring easier). Desolder the switches from thumb cluster PCBs.

You may notice that swiches are glued with hot-melt adhesive. To remove it, just wipe it with isopropyl alcohol. It will not dissolve the glue, but make it lose its adhesive properties.

4. Hand-wire the key-wells. You need ROW2COL direction, i.e. the anode of each diode must be connected to a switch pin, cathode (marked by black strip) — to row. See Modern handwiring guide.
5. Assemble thumb cluster PCBs.
6. Assemble top row PCBs or use hand-wiring.
7. Assemble the controller PCB.
8. Case. Cut two windows for new top row keys. You can use hot-melt adhesive to glue the plates to the case. Seal the holes on the back of the case with pieces of plastic. Glue the USB connector to the back of the case. Optional: use bitumen sound deadening pads to improve acoustics.
9. Setup the QMK.
10. Flash the firmware: qmk flash -kb kin80 -km default. Hold 'boot0' button on MCU board, press 'reset', then release 'boot0'.