Katia is an open-source split mechanical keyboard derived from the popular Corne (Crkbd) platform. The project preserves compatibility with existing Corne mechanical components while introducing a complete electrical redesign focused on professional PCB engineering practices.

Many open-source keyboard designs prioritize functionality and cost, but often make compromises in signal integrity, EMC performance, protection circuitry, and manufacturability. Katia addresses these limitations through a ground-up PCB redesign using a four-layer stackup and modern hardware design techniques.

Key improvements include controlled-impedance USB differential pair routing to improve signal integrity, a dedicated internal ground plane to provide low-impedance return paths, and optimized grounding with stitching vias to reduce EMI. Power integrity was improved with additional decoupling capacitors and ferrite filtering, while ESD protection and resettable fuses were added to protect critical interfaces. The LED control circuit was redesigned with a dedicated level shifter for more reliable operation. Test points and a Tag-Connect footprint were added to simplify programming, debugging, and production testing. The PCB also uses manufacturing-oriented design rules, improved assembly practices, and LCSC part numbers in the BOM to streamline fabrication and sourcing.

The result is a keyboard PCB that retains the ergonomics and ecosystem compatibility of the original design while significantly improving electrical robustness, serviceability, and production readiness.

The project is fully open source under CERN OHL v2-P and includes complete KiCad design files, manufacturing outputs, assembly documentation, and firmware support through QMK.

The project serves as a practical example of how signal integrity, EMC considerations, protection circuitry, and design-for-manufacturing principles can be integrated into a consumer electronics product. Rather than creating an entirely new keyboard, Katia improves an established design and provides the community with a reference implementation of modern PCB engineering practices using KiCad.

Complete hardware design files, documentation, and the latest manufacturing resources are available at: https://github.com/ikajdan/katia.