3DX PIR Motion Sensor Alarm
This was fun. Using a PIR to detect motion. Red and Green status LEDs. Piezo buzzer for audible alert and an LCD screen to display messages about alarm status.
See LCD project for LCD wiring and instruction on connecting to an LCD. https://www.thingiverse.com/thing:2618538
Video of 3DX Motion Alarm in action: https://www.youtube.com/watch?v=e_KAaXct0F4&feature=youtu.be