Designed for use in custom mechanical (split) keyboards, 0xB2 - splinky is an open-hardware development board designed and shared by Charles aka plut0nium.
Features
Pro Micro / Sparkfun RP2040 compatible footprint with 5 extra pins (GPIO12..16) at bottom a la Elite-C
Raspberry Pi RP2040 MCU
Up to 16MB flash memory (depending on component selection and availability)
User LED & USB VBUS detect (GPIO19)
Low profile USB-C mid-mount connector
Designed to be manufactured and assembled by all common PCBA services
This pinout is a de facto standard, established by actors of the MK community (see discussions in #RP2040 on the bastardkb Discord server) – Charles.
Resources
GitHub repo with required information (gerbers, bom, pos) for assembly e.g. by JLCPCB.: