espalarm

Wireless PIR alarm system using ESP32-C2 modules.

Architecture

• Central node (ESP32-C2 dev board with NeoPixel): Runs WiFi AP, listens for motion alerts via UDP, flashes red LED + activates buzzer relay for 3 minutes, then pulses green
• Sensor nodes (ESP32-C2 Mini with HC-SR505 PIR): Connect to central AP, send UDP packets on motion detection

Hardware

Central

• ESP32-C2 dev board (GPIO8 = WS2812 NeoPixel)
• Relay module on GPIO3 (buzzer/siren)

Sensor

• ESP32-C2 Mini
• HC-SR505 PIR sensor on GPIO4
• Power via USB

Building

Requires ESP-IDF v5.3+. Binaries are built automatically via GitHub Actions.

Local build

cd central  # or sensor
idf.py set-target esp32c2
idf.py build
idf.py flash

Configuration

WiFi credentials and GPIO pins are defined in components/protocol/include/alarm_protocol.h.

Default AP: espalarm / espalarm123