ThinkPad TrackPoint Translator

ThinkPad keyboards and TrackPoint pointing devices are somewhat legendary, with many connoisseurs preferring older IBM models to current Lenovo products.

It’s no surprise then to see a late 90s IBM ThinkPad 380ED’s peripherals still in use today, although doing so presents a challenge in that unlike newer models, the resistive strain gauge that measures TrackPoint input does not convert it to PS/2.  Frank Adams (thedalles77) has once again solved this challenge as part of the larger USB Laptop Keyboard Controller project.

The project consists of a custom PCB, in order to provide the required connectors, an Analog Devices AD8236 Instrumentation Amplifier reading each channel of the strain gauge, and TI LM358 op-amps providing a reference voltage. Code and documentation can be found on GitHub, with additional detail on Hackaday, and a detailed overview in the video below.