Using a $15 Arduino Uno clone, a developer turned a breadboard into a home‑security hub. Before soldering, he scraped public satellite images, street‑view data and Wi‑Fi scans—classic OSINT—to map blind spots and traffic patterns. That intelligence dictated where motion, magnetic door and ultrasonic sensors would sit.

Choosing the simplest Uno gave access to enough I/O pins for a small sensor array. He wired motion detectors, magnetic contacts, photocells and a yard‑sale ultrasonic module for under $50 total. Alerts trigger a local buzzer, log to an SD card, and optionally fire SMS via an ESP8266 bridge.

Python scripts read the serial feed, timestamp each event and classify severity, letting the system learn false‑positive patterns. By cross‑referencing sensor spikes with publicly known delivery schedules, the hub predicts genuine intrusions rather than ambient noise. The author bundles the code and step‑by‑step instructions in a DIY Guide sold on Gumroad, inviting others to replicate and iterate.