Pica40 v2

Split keyboard with 40 keys using XIAO controllers.

Pica pica - european (common) magpie

Features

• 40 keys
• high profile (regular MX switches with hotswap sockets) or low profile (soldered low-profile ChocV2 switches)
• wired/wireless versions
• aggressive stagger
• slightly splayed for pinky columns

Wired version

• XIAO RP2040 controller
• QMK firmware
• USB-C or TRRS connection between splits
• one rotary encoder (without click)
• status LED

Wireless version

• XIAO nRF52840 BLE controller
• ZMK firmware
• two rotary encoders (without click, only master side encoder is currently supported by ZMK)
• on/off toggle
• battery connectors

Photos

wired version with 3d printed case

wired/wireless versions with Choc V2

Pica40 family - ChocV2 with low profile keycaps, ChocV2 with MT3 keycaps, Pica40 v1 with MT3 keycaps, regular switches and hotswap sockets

Firmware

• QMK - available in main repository, also check my fork for most recent updates. Compiled file.
• Vial - my fork. Compiled file.
• ZMK - Source code, compiled left, compiled right, reset

Gerber files

• PCB
• Bottom plate

Case files (STL - 3d printed, MX hotswap only)

All files are in stl folder.

Top:

• wired/wireless versions
• with and without encoders
• normal and thin versions (see bottom parts for difference)

Bottom:

Thin version - just cutouts for all elements, as low as it can be. May be combined with normal top case and metal bottom plate for additional weight. Normal (with legs and without):

Case files (DXF - for metal/acrylic)

• Curved bottom for MX hotswap with 3D printed case
• Bottom for soldered ChocV2
• MCU cover
• MCU cover with encoder hole

Bill of materials

• PCBs
• 2 XIAO MCUs - RP2040 for wired version, nRF52840 for wireless
• 40 SMD SOD-123 1N4148 diodes
• 1 or 2 EC11/12 rotary encoder with knob (diameter up to 20mm)
• [MX hotswap version] 3d printed case (top and bottom, left and right - 4 files)
• [MX hotswap version] 40 hotswap sockets
• [MX hotswap version] M2 standoffs (4mm for thin, 5mm for normal), 3mm M2 screws with flat head
• [MX hotswap thin version] 8x2mm magnets (optional)
• [ChocV2 soldered version] FR4/metal/acrylic bottom plates, metal/acrylic MCU cover (optional)
• [ChocV2 soldered version] 6mm M2 screws, M2 nuts and washers
• [Wired only] USB-C 16pin connectors
• [Wired only] TRRS PJ-320A connectors
• [Wireless only] 2x on/off toggle MSK-12C02
• [Wireless only] 2x Li-Ion 3.7V battery (up to 25x14x5 for standard case)
• Rubber sheet or 5x15 legs

Build log

TODO

Changelog

V2.1

• added TRRS support
• wired version supports rotary encoder on any side
• remove unused for FR4/acrylic/metal sandwich case, 3D printing is better and cheaper
• improved 3D printed case with a new shape and parts

V2

• reworked to true split with two XIAO MCUs controllers
• added splay to pinky columns
• all case/pcb files are not compatible with V1

V1

• split with single Pro Micro based MCU and handwired connection

Support

If you like my work and want to support my future designs, please consider sponsorship.