GitHub - nicholasbester/arduino-keyboard-instrument: A Keyboard instrument made using pushbuttons and a piezo speaker on an Arduino http://www.nickbester.com
Connect A 4x4 Keypad To One Arduino Input - The DIY Life
Using a 4x4 Digital Keypad with Arduino • AranaCorp
Green Lcd Screen Keyboard Expansion Board for Arduino Uno Mega 2560 16X2 | eBay
20pcs 4 Key Button Keypad Switch Keyboard Module for Arduino UNO Breadboard | eBay
Dashboard Keyboard With LCD Display and Arduino Uno : 9 Steps - Instructables
Amazon.com: SunFounder FruitKey USB Keyboard DIY Starter Kit Gamepad Control Handle DIY Computer Keyboard, Worked with PC Mac OS X Raspberry Pi for Arduino Uno R3 Leonardo : Electronics
How To Use A Keypad With Arduino - Makerguides.com