qmk_firmware/docs/compatible_microcontrollers.md

Compatible Microcontrollers

QMK runs on any USB-capable AVR or ARM microcontroller with enough flash space - generally 32kB or more, though it will just squeeze into 16kB with most features disabled.

Atmel AVR

The following use LUFA as the USB stack:

• ATmega16U2 / ATmega32U2
• ATmega16U4 / ATmega32U4
• AT90USB64 / AT90USB128

Certain MCUs which do not have native USB will use V-USB instead:

• ATmega32A
• ATmega328P
• ATmega328

ARM

You can also use any ARM chip with USB that ChibiOS supports. Most have plenty of flash. Known to work are:

STMicroelectronics (STM32)

• STM32F0x2
• STM32F103
• STM32F303

NXP (Kinetis)

• MKL26Z64
• MK20DX128
• MK20DX256

Atmel ATSAM

There is limited support for one of Atmel's ATSAM microcontrollers, that being the ATSAMD51J18A used by the Massdrop keyboards.