Interfacing a DSC PC1500RK alarm keypad

I have reverse engineered the wiring to a DSC PC1500RK alarm keypad, and as can be seen in the video, I have complete control over what LED is on, when the beeper is on/off, and can completely read any key that is pressed. The keypad is interfaced through an Arduino Mega, although it will work with any Arduino. The protocol for the keypad, is set the data line high, and clock out 8 bits, reading the data line between each clock. Then, to control the beeper/LEDs, clock in 16 bits. Afterwards, delay 20 milliseconds. Arduino sketch located at http://pastebin.com/sN7JnJHM