dariiats/esp32-security-system

Purpose and Entry Point

This is ESP32 firmware for a local smart-security system: PIR motion detection triggers Bluetooth user notification; a user can request or ignore an alarm; an authorized RFID card is required to deactivate an active alarm. The firmware entry point is src/main.cpp, built and uploaded through the PlatformIO project defined by platformio.ini.

Embedded Runtime and Hardware Boundary

The system runs on an ESP32 DevKit and directly controls GPIO-connected PIR, LEDs, and buzzer/alarm circuitry. It communicates with the RFID reader over I²C. Hardware-specific initialization and the continuous device event loop are expected to be centralized in src/main.cpp; the application has no stated Wi‑Fi, cloud, server, or persistent-backend dependency.

Paths:

• src/main.cpp

• platformio.ini

Motion Detection Stage

The PIR sensor is the initiating event source. Motion causes the firmware to evaluate the detected activity and notify the connected Bluetooth client, rather than immediately relying solely on physical alarm output. This establishes a control boundary between physical sensor input and user-directed alarm decisions.

Paths:

• src/main.cpp

Bluetooth Command Control

ESP32 Bluetooth provides the human-control channel, exposing the device as ESP32Security for an Android serial-Bluetooth terminal. The intended command flow is: motion notification → user sends alarm or ignore → firmware changes alarm behavior. Bluetooth is therefore both an outbound notification transport and an inbound command interface.

Paths:

• src/main.cpp

Alarm Actuation and State

The active alarm is represented through visual LEDs and an audio buzzer driven from the ESP32. Alarm activation can be requested remotely; ignoring a motion event suppresses/escalation handling. Deactivation is deliberately gated by RFID authorization, creating a security boundary: Bluetooth commands manage the response decision, while RFID identity authorizes alarm shutdown.

Paths:

• src/main.cpp

RFID Authentication

RFID card reads are handled through the bundled MFRC522 I²C driver. The application compares a presented card’s UID with an authorized UID configured in firmware; only a match may deactivate an active alarm. The local library owns reader-level I²C/register communication, while application policy and authorization belong in the main firmware.

Paths:

• lib/MFRC522_I2C/MFRC522_I2C.h

• lib/MFRC522_I2C/MFRC522_I2C.cpp

• src/main.cpp

Dependency and Build Boundary

The project vendors its RFID dependency rather than requiring external installation. MFRC522_I2C integrates with the ESP32’s I²C/Wire stack and includes a standalone Arduino usage example, while the root firmware remains the deployable security application. PlatformIO is the material build/upload infrastructure.

Paths:

• lib/MFRC522_I2C/library.properties

• lib/MFRC522_I2C/examples/mfrc522_i2c/MFRC522_i2c.ino

• platformio.ini