Pro Micro Arduino clone Atmega32u4 5V/16Mhz

Pro Micro Arduino Clone

by Tweety's Wild Thinking


No tax for United States [change]
Note that nanoBoot is recommended if building Lotus58 with VIAL Firmware
Stock available: 1

The most popular and common DIY keyboard controller!

An Arduino clone based on the Atmel Atmega32u4 MCU


  • USB port (Select USB-C or USB Mini B connector)
  • Standard 24-pin interface, fit's many (most?) DIY keyboard designs
  • Atmega32u4 5V & 16 Mhz (The most common used on keyboards)
  • Serial, I2C, SPI, PWM and more
  • 18 usable IO pins for your keyboard

What's included

As standard, these are delivered in a sealed ESD bag, with the 2 pinheaders just like any Pro Micro clone.

I'm merely reselling these As-is to make it a one-stop-shop for building your keyboard.

Please note! You can likely find them cheaper on AliExpress or similar if you are willing to order from various sources. I'm merely covering my expenses, shipping/taxes etc, with no profit on these.

Note about USB-C Version

Due to the fact that the PCB of the USB-C variant is a bit longer, and the USB-C connector is a slightly thicker/larger in it self, on most designs mean to fit both the 'classic' mini B connector, the USB-C variant Pro Micro sticks out ever so slightly. This is a cosmetic issue only, and doesn't affect the function in any way. But it should be kept in mind when making a choice between the two types, since you can't really change your mind when you see it in real life.

Optional bootloader

As an added option, the Pro Micro can be delivered reflashed with a minimal bootloader. This gives you a lot more usable memory space for advanced QMK keymaps or using VIAL.

Using a Pro Micro controller is a very good 'easy' option as a beginner or for a low cost build, but with more and more advanced features added to QMK needing more memory to compile, or using VIAL for dynamic real-time keymapping, the Atmega32u4 is quickly running out of usable memory. The 'standard' Caterina bootloader is rather old code, and while convenient as it is the expected bootloader, working with any pre-compiled firmware out-of-the-box, it's using a fair amount of memory for not a lot of actual functionality.

Switching to a more modern, efficent bootloader gives you a lot more usable memory, but requires you to use an external programmer, as this cannot be flashed using the USB port and QMK Toolbox. nanoBoot, is a tiny HID-bootloader, meaning no additional drivers needs to be installed on your OS, and at just 512kB it's far smaller than Caterina with near identical functionality and in my experience better performance.

Using an external programmer can be daunting as a beginner, and not everyone owns one. (However an additional Pro Microcan be used as one!) So when purchasing a controller for your keyboard build, you can choose to have it pre-flashed with nanoBoot, ready to use as normal flashing the userspace firmware (QMK/VIAL) as normal using QMK toolbox, with minimal editing of the source, or using the precompiled VIAL firmware for keyboard designs sold in this shop.

nanoBoot bootloader

  • Only 512kB, giving you more usable memory
  • Fully compatible with QMK/VIAL (need's firmware re-config/compile)
  • HID-bootloader, no OS-side driver installation needed
  • Userspace firmware can be flashed with QMK Toolbox as normal

Links to code and documentation

No additional links provided for this product.

Shipping policy

Normal handling time is 3 - 5 working days, not including build items (1 - 2 weeks).

Shipping is mainly insured/signed for parcels, where no such service is available the parcel is sent as untraceable/uninsured parcel (Clearly noted at shipping selection), at the buyers responsibility.

All packets are represented to courier services and customs at their true sale value, and all responsibility for import fees, taxes and tariffs lie with the buyer.

All sales are considered final and non-refundable once an order has shipped.

The seller

Tweety's Wild Thinking

Skurup, Skane lan, Sweden
46 orders since May 21, 2022
Designing and selling keyboard related kits of all types. Sales in this store is mainly funding new designs.
All items are continually restocked, and if nothing else is noted, should restock in 7-10 working days.
Custom design requests welcome.