Zmk-Thinkpad on congx.dev

ZMK-ThinkPad - Part 3: Connector arrived, and then there was light

Tue, 25 Aug 2026 15:00:00 +1000

Summary

Backlight on Revision A does not work. The power circuit browns out. So I turned to my trusted friend: National Semiconductor Analog Discovery 2, plugged in the T480 keyboard, and backlight was lit. It wasn’t pretty, but at least it works.

12 pins into a 14-pin connector

The 14-pin connector is a generic FFC connector.

As much as I hoped that it’d just fit like the 40-pin FFC connector, the dimension don’t quite work. There needs to be some rejigging and alignment. I 3D printed a guide.

ZMK-ThinkPad - Part 2: Revision A

Tue, 25 Aug 2026 12:00:00 +1000

Summary

Rev A PCB has arrived, and after a gruesome 8-hour long PCB soldering - my skills have deteriorated - a PCB is finally done!

The first target for a ThinkPad T430 keyboard due to:

I haven’t found a TrackPoint connector yet. The 14-pin 1mm pitch connector hasn’t arrived.
My T430 keyboard has a backlight that I could test first with.

Code repository: https://github.com/rampadc/zmk-thinkpad

Schematics: http://congx.dev/zmk-thinkpad/reference/hardware-files#t430-revision-a

What worked

Keyboard matrix scanning
TrackPoint pointer
Logitech-Switch support: https://www.logitech.com/en-au/discover/a/easy-switch-technology
UF2 bootloader: after initial flashing with SWD, I can use the USB-C connection develop.
Mute, MicMute, Power LEDs

What didn’t

TrackPoint buttons - but T60 keyboard’s TrackPoint buttons work.
Battery measurement: need to add a fuel gauge in Rev B.
Backlight: power circuitry brown out the moment backlight is routed. +5V by itself is stable but loading the T430 keyboard brown out the circuit. Most likely a T430 keyboard fault.
Lots of components to manually place

I am thankful that I have a few spare T60 keyboards and 1x T480 with backlight keyboard lying around. Without them, I would not have been able to verify that the backlight mechanism on a different dev board or that the TrackPoint buttons on the T430 were defective.

ZMK-ThinkPad - Part 1: Project inception and mapping the T470 keyboard

Tue, 11 Aug 2026 12:00:00 +1000

The T470 keyboard connector problem

I’ve had a spare ThinkPad T470 (or maybe T480) keyboard sitting in pristine condition in a unmarked groceries bag in a moving box for the past 10 years. I could never proceed with it because just like most Lenovo contraptions, the connectors almost impossible to get.

T470 (and T480) actual connectors are:

KBD: HIGHS_FC5AF361-1151H
TrackPoint: HIGHS_FC1AF121-1151H

Top contacts. KBD is 36-pin 0.5mm pitch, TrackPoint is 12-pin 1mm pitch.