AlarmistYour iPhone Has a LiDAR Sensor You're Not Using. It Can Guard Your Door in Complete Darkness.Every iPhone Pro has a LiDAR sensor that fires invisible infrared light and measures depth. It works in complete darkness. I turned it into a motion detection alarm for hotel rooms, dorm rooms, and anywhere you sleep in unfamiliar places.February 6, 2026
AlarmistCan Your iPhone Replace a Security Camera? Camera vs LiDAR for Motion DetectionPeople ask if they can use an old iPhone as a security camera. The answer is yes, but cameras fail in the dark. Your iPhone Pro has a LiDAR sensor that detects motion using infrared, no light needed. Here is when to use each one.January 10, 2026
AlarmistHotel Room Security: A Practical Guide to Sleeping Safely in Hotels and AirbnbsHotel doors have master keys. Airbnb hosts have spare keys. Here is a practical, layered approach to securing your room at night, from physical hardware to LiDAR motion detection on your iPhone.December 15, 2025
