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0xCB Helios

The 0xCB Helios is an Elite-C compatible development board sporting an RP2040 chip.
Published January 2, 2023
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After the 0xCB Pluto sporting an Atmega32u4, Jakob and Conor announced the 0xCB Helios with an RP2040 chip. Pro Micro/Elite-C compatible, open source, and available at as well.

The Pluto is based on the AtMega, Helios is based on RP2040. With this new IC the controller gets cheaper, but is way more powerful feature and space wise. You can do a lot more stuff with displays for example – 0xCB-dev.


  • Pro Micro/Elite-C compatible footprint
  • 26 GPIO pins
  • 16MB (128Mbit) of flash
  • Dual ARM Cortex-M0 @133MHz
  • 264kB SRAM
  • default off red power LED
  • blue user LED
  • a level-shifter to drive 5V components
  • onboard ESD protection chip
  • VBUS detection support for split keyboards
  • D+ and D- pads
  • "unbrickable" bootloader: its located in ROM on the rp2040 itself
  • single button reset circuit (reset the board with a short press and enter the bootloader with a long (>500ms) hold).
  • price: €17 (with headers for all three sides)

The one button reset circuit is based on the one used on the Sea-picro by Josh Johnson.

No silk art this time, the 0xCB team opted for a stealth design to go as sleek as possible so that the controller blends in with most keyboards.


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Published on Mon 2nd Jan 2023. Featured in KBD #109 (source).


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