The objective of our project was to create an alarm system that could detect an intruder using an IR motion sensor. We used a keypad so the user could enter their password to arm and disarm the system.
We also included an LCD so that users would be informed which state the alarm system was currently in as well as giving the user a response when entering their password (by showing *’s for each character). Motion was detected by using a simple IR sensor that pulled low when motion was detected.