Project · Dec 2022
SweetSignal SmartHome IoT
SweetSignal SmartHome IoT is an end-to-end smart-home platform built for the Introduction to Robotics & Lab course (Fall 2022, KNTU). An Arduino-based controller (ESP8266/ESP-01 + L298N) publishes sensor data over MQTT to a Mosquitto broker, Node-RED bridges the data into InfluxDB for time-series storage, and a Django REST API serves the history and relays actuator commands back to the hardware. A Flutter mobile app provides JWT-authenticated login and device control.
The architecture flows sensor data (gas, lamp, water, lock) from the Arduino → MQTT (Mosquitto:1883) → Node-RED → InfluxDB (org sweetsignal, bucket IOT-buck). The Django API (:8000) exposes GET/POST /api/read/<topic>/ for querying time-series data and POST /api/write/<topic>/ for sending actuator commands, secured with JWT authentication (simplejwt) and staff-only access. Commands published to MQTT topics (controller1/lamp, controller1/water, controller1/lock, controller1/gas) are received by the hardware.
Hardware subsystems on the Arduino include a gas valve (L298N + stepper, 1385° rotation), lamp (relay/digital out), lock (digital out), and water tap (motor + open/closed limit switches). The firmware uses PubSubClient and WiFiEsp libraries on ESP8266 with SoftwareSerial.
The stack is containerized with Docker Compose orchestrating Mosquitto, Node-RED, InfluxDB, and the Django backend (gunicorn). CI runs style checks (pycodestyle) and unit tests (with InfluxDB/MQTT mocked) on every push. The Flutter frontend provides a clean mobile interface for monitoring sensors and controlling actuators remotely.