This disguised campsite security system lets you know ‘hoos’ there
Motion sensors for home security stick out like a sore thumb, as their shiny white exteriors can be easily seen from a distance. This is made worse when camping, as small, discrete security devices that blend into their surroundings are even harder to come by. This is what inspired Sean Miller to create his own that uses automotive bumper sensors to detect intruders and play loud noises when necessary. Better yet, the circuitry for this project was stuffed inside of an owl decoy, making it the perfect unassuming campsite guardian.
At the heart of this disguised intruder detection system is an Arduino MKR Zero, which handles both the incoming distance readings from the sensors and playing various sounds from an onboard SD card. Miller had to perform a few hacks to get the automotive sensors working, as they use different custom protocols that can vary between manufacturers. After figuring it out, he then wired up the sensors to the MKR Zero and connected a small speaker to a custom amplifier circuit. With the electronics completed, he produced some code that checks the distances between the owl and any obstacles, with an alert being produced if an intruder is detected nearby.
You can read more about how Miller built this intruder-detecting owl here on Instructables, as well as see how he added an optional ESP8266 for sending alerts to his phone.