A small Wi-Fi security node that watches a door or a room and pings me when something happens.
Overview
Home security is one of those IoT projects where the problem is easy to describe and surprisingly fun to actually solve. I built a small ESP node that watches a door and a room, posts events to a remote channel, and lets me know when something happens.
Sensors report intrusion events to the MCU. The Wi-Fi node sends data to a remote service and can activate local alarm feedback.
Project photos
IoT home security prototype
Implementation details
Firmware
Firmware reads sensors, debounces events, connects to Wi-Fi, posts alert messages, and can trigger local alarm outputs.
Power
Low-voltage DC supply powers the controller and sensors; battery backup can be added for security reliability.
Components / BOM
ESP8266/ESP32 board, PIR sensor, Reed switch, Buzzer/status LED, Power adapter
Engineering challenges
Reliable Wi-Fi reconnection after router restarts, filtering out false PIR triggers, and avoiding the trap of spamming alerts every time the device sees anything.
Solutions
Debounced the sensors in firmware, added simple rate-limiting on alerts, and made sure the device reconnects to Wi-Fi cleanly after a drop.
Results & metrics
A prototype that runs for long stretches and quietly does its job without false alarms.
Future improvements
Camera snapshots on triggers, battery backup, mobile push notifications, encrypted device provisioning and a small dashboard for multi-room setups.
