4 layers57 × 33 mm

Sensor pcb
nichlock/open-linear-scale
Open-source capacitive linear encoder / DIY DRO scale: KiCad PCBs, STM32 firmware, and test data. Same principle as digital calipers.
69 parts73
KiCad boards from 1 GitHub repository tagged “linear-scale-position”, the most starred first; open any of them in PCBKit.

nichlock/open-linear-scale
Open-source capacitive linear encoder / DIY DRO scale: KiCad PCBs, STM32 firmware, and test data. Same principle as digital calipers.