EC23U

Open source numpad Electrostatic Capacitive PCB.

Introduction

This project is a continuation of my development of open source EC boards.

The supported layout options are the following:

Technical information

• Layout size: 23U layouts with alternative options
• Compatible switches: EC switches (Topre and NIZ)
• Microcontroller: STM32F401
• Connector: Original OEM JST connector
• Firmware compatibility: QMK (with VIA/VIAL support)
• Protection hardware (present on both the mainboard and both controller versions):
  • Fused
  • ESD protection
• Addressable RGB LED support
• Numlock LED support

Renders and Prototypes

Render

Prototypes

NOTE: The silkscreen text near the JST connector has the GND and VBUS label swapped. This is wrong and have been fixed in the latest revision.

Revisions and relative features

Rev1.0

This revision implements all the main features of the mainboard ad controllers mentioned in the specifications.

RGB header

The mainboard features an RGB header for connecting +5V addressable RGB strips. THe properties of the lighting can be controlled through Vial or by assigning RGB control keycodes on the board itself.

NumLock Indicator

The mainboard features a NumLock indicator LED. The LED is controlled by the MCU and reacts based on the system state. The LED used is a 3.0mm THT LED. Polarity is signalled by the silkscreen. The indicator is optional.

DFU

To access the DFU mode of the mainboard you can perform one of the following actions:

• press the key to which the QK_BOOT keycode is assigned (if available)
• while plugging in the board short the Boot0 pins on the mainboard

PCB order procedure

Production files

The production can be found in the Production folder.

In there you'll find the main PCB files and the JIS and HHKB plates.

As usual the *.zip files are the gerber files, BOM-*.csv are the BOM (Bill Of Material) files and POS-*.csv are the POS/CPL (Footprint POSition/Component Placement List) files.

Assembly options

Here follows the options to be used for assembly:

• Assembly Side: Bottom
• Confirm Parts Placement: yes

Copyright notice

This project is not endorse nor sponsored in any way by Topre Corporation and PFU Limited. The HHKB Logo and Topre logo are trademarks of their respective owners.

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.