RP2040 MCU with 4MB Flash & USB-C

A better Bit-C

The Bit-C PRO is a microcontroller (MCU) featuring the Raspberry Pi RP2040, designed for DIY keyboards. It features a through-hole USB-C connector that is more rugged than a USB micro B. It's only 1mm thick, so it sits slim and low. The Bit-C PRO ships with the RP2040 UF2 bootloader, which enumerates as an external USB drive: flashing firmware is as simple as drag and drop, no driver installation required. 100% of Bit-C PRO units are 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 PRO is a drop-in replacement for any Pro Micro MCU, including the original Bit-C and Elite-C. With 4 more GPIO pins than the Pro Micro, it's more versatile than even the Bit-C. The Bit-C PRO ships with 4MB of flash storage, which is over one hundred twenty times more than the 32KB of storage on the Pro Micro! Overcurrent, overtemperature, and backdrive protection are included on every board.


The built in RGB LED shows power status by default, and can be dimmed to different brightnesses using PWM control. Don't like the built-in LED? Turn it off. Use it to show layer or caps lock status. Plus, the LED is easily configurable from QMK, Arduino, and MicroPython.

Comprehensive software support

The Bit-C PRO is supported by Arduino IDE, MicroPython, CircuitPython, QMK firmware, and more. Multiple language and framework support means that it's easier than ever to get your project up and running. Jump in with the Quickstart Guide.

Bit-C Comparison Table

Bit-C PRO RP2040 Bit-C AVR 32U4
CPU architecture RP2040: ARM Cortex M0+ ATmega 32U4: AVR
CPU clock Dual core @ 133MHz Single core @ 16MHz
GPIO Voltage Level 3.3V 5V
Flash size (program storage) 4MB on-board 16kB on-chip
RAM size (variable and data storage) 264kB on-chip 2.5kB on-chip
QMK firmware support
Arduino IDE support 1
Micropython support
Circuitpython support
Electrically compatible with Bit-C PRO RP2040 2
Electrically compatible with Bit-C AVR 32U4 2

1 The Bit-C AVR 32U4 can be used with Arduino IDE, but requires flashing a new bootloader.
2 The Bit-C PRO RP2040 and Bit-C AVR 32U4 cannot be "mixed and matched", as they use two different electrical voltage levels. For example, if building a split keyboard such as the SNAP, both Bit-Cs must be the same model. Boards connected over TRRS must also use the same MCU.

Included in the box

  • Bit-C PRO 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.


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