/goldfish

A small, thin, USB-C, Pro Micro compatible microcontroller

Goldfish v2

Note

The main branch contains the design for Goldfish v2. The Goldfish v1 design is available in the v1 branch

Goldfish is a Pro Micro compatible microcontroller board designed for use in mechanical keyboards. It is based on the same Atmel ATMega32U4 chip and is programmable using the Arduino IDE or a keyboard specific firmware such as TMK or QMK. Of course it is perfectly usable for any other electronics projects too, not just keyboards.

preview

Links

Features

  • Lower board profile with the mid-mounted USB-C connector
  • Two internal pins make the USB data lines easily accessible
  • USB-C is more durable, reversible and just plain cool
  • 5 additional pins on the bottom edge of the board
  • Pin-compatible with the original Pro Micro
  • Sturdier through-hole USB connector
  • On board ESD protection for USB lines

Changes compared to Goldfish v1

  • Addition of on board ESD protection and fuse
  • All 0603 resistors and capacitors for (slightly) easier hand assembly
  • Castellated edge connectors similar to the Elite-C
  • Less obscure USB-C connector
    • Use of more commonly available components in 2022
    • Choice between multiple compatible connectors and suppliers
    • Uses USB 2.0-only connector for easier and cheaper assembly

USB-C Connectors

Manufacturer Part number
Molex 216990-0001 - 216990-0003 216990-0002
HRO - TYPE-C-31-M-13C TYPE-C-31-M-13B TYPE-C-31-M-13A
GCT USB4520 USB4510 USB4505 USB4500
Approx. thickness
1.2 mm PCB		 c21p12
3.2 mm		 c16p12
3.2 mm		 c10p12
3.4 mm		 c08p12
3.6 mm
Approx. thickness
1.6 mm PCB		 c21p16
3.2 mm		 c16p16
3.2 mm		 c10p16
3.8 mm		 c08p16
4.0 mm

Limitations compared to a Pro Micro

  • No onboard RX, TX LEDs
  • No onboard voltage regulator (this makes no difference for keyboards; a regulator is only required when power supplies of over 5.5V are used)

Vendors Selling Goldfish

Goldfish v1 rev. C

Comet (modified design based on Goldfish v1; see related projects)

Note: These products are sold by 3rd party vendors and are not 'officially' endorsed by me. I'm simply listing them here for convenience.

(Also please let me know if anything is missing from this list)

Related Projects

Alvaro by Ariamelon

  • A modified Goldfish v1 using 0603 components instead of 0402

Comet by Tokas

  • A modified Goldfish v1 using a HRO TYPE-C-31-M-12 connector

Whale by Jia Geng Chang

  • A modified Goldfish v1 using a Jing 918-418K2024S40000 connector

Goldfish-clone-JLCPCB by Jeremy J Starcher

  • A modified Goldfish v1 designed to meet JLCPCB's assembly requirements

Elite-C from keeb.io

  • An unrelated and closed source project with similar design goals

(Please let me know if anything is missing form this list)

License

Released under the Creative Commons Attribution Share-Alike 4.0 License. https://creativecommons.org/licenses/by-sa/4.0/

Original Arduino Mini Design by Team Arduino. Arduino Pro Mini Design by Spark Fun Electronics. Pro Micro Design by Spark Fun Electronics. Goldfish Design by Lucas Jansen.