Turn your ProMicro into a USB Keyboard/Mouse - SparkFun Electronics
64-Key Prototyping Keyboard Matrix for Arduino - Hackster.io
FMC/Dual Encoder Questions
Arduino | Matrix Keypad | Adafruit Learning System
Arduino Tutorials – Chapter 42 – Numeric Keypads | tronixstuff.com
Arduino AVR C++: Simple USB HID multimedia keyboard based upon standard keyboard class - Stack Overflow
How to use a keyboard in arduino
Use a Keypad with Your Arduino - Projects
Using a 4x4 Digital Keypad with Arduino • AranaCorp
Arduino: Library for multiple keypads
Enginursday: Pressing Our Buttons - News - SparkFun Electronics
PS2Keyboard Library, Connect a keyboard for user input
How to Set Up a Keypad on an Arduino - Circuit Basics
Arduino Keyboard - Hackster.io
Connect Arduino UNO to USB Keyboard
GitHub - julianschuler/USBKeyboard: Arduino library to add HID USB keyboard functionality to your projects
How to read input from USB keyboard on Arduino
atmega32u4 - Using Keyboard library for ISO-UK layout - Arduino Stack Exchange
Turning An Arduino Into A USB Keyboard | Hackaday
Arduino Keyboard Is Gorgeous Inside And Out | Hackaday
64-Key Prototyping Keyboard Matrix for Arduino : 6 Steps (with Pictures) - Instructables
atmega32u4 - Using Keyboard library for ISO-UK layout - Arduino Stack Exchange
Keypad with arduino tutorial - miliohm.com
