I am building a Motion sensor alarm system for school. I am using a P.I.R sensor and a 16x2 LCD screen. When someone passes by the sensor, a buzzer will sound and. I got the idea from instructables.com. I would like to incorporate a 4x4 hex keypad with this project. Any ideas and solutions will greatly help. Thank you.
Google is very helpful. Here are the top two results:
http://playground.arduino.cc/Code/Keypad
http://playground.arduino.cc/Main/KeypadTutorial