Pro Micro Compatible MCU with USB-C

A (much) better Pro Micro

The Bit-C is a microcontroller daughterboard featuring the Atmel ATmega32U4, designed for DIY keyboard enthusiasts. It features a sturdy through-hole USB-C connector that is more rugged than a standard USB micro B. It's only 1mm thick, so it sits slim and low. The Bit-C ships with the Atmel DFU bootloader, which is smaller and less finicky than the default Caterina bootloader. 100% of Bit-C units are exhaustively tested before shipping, ensuring you're spending your time building, not debugging. Best of all, it comes in white!

100% Pro Micro compatible

The Bit-C is a drop-in replacement for any Pro Micro MCU, including the Elite-C. With 1-1 GPIO pin parity, firmware builds don't need to be changed in order to swap in a Bit-C. The Bit-C is shipped with the lightweight Atmel DFU bootloader, making flashing with QMK a breeze. VBUS detection & backdrive protection are implemented for split keyboards, and a 500mA resettable fuse is included for protection.

Tri-mode LED

The built in white LED shows power status by default, and can be set to 3 different brightnesses using GPIO controls. Don't like the built-in LED? Turn it off. Use it to show layer or caps lock status. Bright, dim, and off modes allow for maximum flexibility.

See it in the wild

Check out community-posted images sourced from the nullbits Discord server, Reddit, and more.

Included in the box

  • Bit-C MCU

OS Compatibility

Supported by all major versions of Windows, MacOS, and Linux. Fully compatible with USB 2, USB 3, and USB-C. No driver installation required for MacOS and Linux; Windows 7/8/10/11 may require driver installation. See here for info.


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