📌 Used parts:

Custom designed PCB from NextPCB.com:

https://www.nextpcb.com/blog/pc_keyboard

Arduino Pro Micro:

https://www.ebay.com/itm/New-Pro-Micro-ATmega32U4-5V-16MHz-Replace-ATmega328-Arduino-Pro-Mini/221891843710?epid=1042391255&hash=item33a9c8d67e:g:D70AAOSwVL1V~1dn

Cherry MX Switches:

https://www.ebay.com/itm/20-pcs-Cherry-MX-Brown-original-mechanical-keyboard-switch-MX1A-G1DW/222052763041?hash=item33b36045a1:g:fZ8AAOSwpzdWr50A

2N7002 MOSFET:

https://www.ebay.com/itm/50x-2N7002KT1G-Transistor-N-MOSFET-unipolar-60V-0-38A-0-42W-SOT23-3/223540764411?hash=item340c115efb:g:oisAAOSwPdNc9m1Y

1206 SMD Resistors (1 x 1K, 1 x 10K, 2 x 22):

https://www.ebay.com/itm/1206-Smd-Resistor-Kit-Assorted-Kit-1Ohm-1M-Ohm-1-33Valuesx-20Pcs-660Pcs-Sa-X7B3/123823792184?hash=item1cd4792038:g:4D4AAOSwkCddHXuR

M2 x 4 mm screws:

https://www.ebay.com/itm/10-20-50-100x-M2-M3-M4-M5-Stainless-Steel-Hex-Bolt-Socket-Cap-Screws-Head-DIN912/173028404303?

📌 Other:

3D File:

https://www.thingiverse.com/Elite_Worm/about

Code:

https://github.com/EliteWorm/Mini_PC_Keyboard/blob/master/Mini_PC_Keyboard_V1_0_0.ino