qmk_firmware/keyboards/ymdk_np21
..
keymaps/default
README.md
backlight.c
backlight_custom.h
breathing_custom.h
config.h
i2c.c
i2c.h
matrix.c
rules.mk
usbconfig.h
ymdk_np21.c
ymdk_np21.h

README.md

YMDK NP21

kp21 — full grid layout

ps2avrGB based number-pad sold fully assembled by YMDK on Aliexpress.

Keyboard Maintainer: QMK Community
Hardware Supported: Atmega32A Hardware Availability: AliExpress

Make example for this keyboard (after setting up your build environment):

make ymdk_np21:default:program

Plugging the board in while pressing 'Top Left Key' (USB on top) will force it to boot bootloader without loading the firmware.

The code for NP21 is a minor edit of jj40.