FishMaster is an IoT aquarium monitor that tracks water quality and controls feeding using an ESP32 with a Spring Boot backend and React frontend.
FishMaster is a smart aquarium system that monitors and controls key aquarium conditions through two layers: an embedded local system and a web-based system.
The embedded system uses an ESP32 microcontroller with sensors to measure 3 main parameters (pH, Temperature and Turbidity). Readings appear on a local LCD touch screen, and a servo-driven feeder handles scheduled and condition-based feeding. This setup works entirely offline, so the aquarium stays managed even if the network fails.
The web system adds cloud connectivity. The ESP32 uploads data to a backend, and users can view their aquarium through a mobile or web interface. The dashboard includes charts, historical data, and remote monitoring. If the network becomes unavailable, the system automatically switches back to the embedded mode.
The system is designed to work whether or not there is an internet connection.
- Local System (Offline): The ESP32 reads sensors and controls a servo motor for feeding. It shows the current readings on an LCD screen. If the Wi-Fi goes down, the feeding and monitoring still work.
- Web System (Online): The ESP32 sends data to the backend. Users log in to a website to see charts, check history, and manage settings for multiple tanks.
Figure 1: Fishmaster System Overview diagram
FishMaster uses a hybrid IoT architecture with two main data flows:
- 🔵 Sensor data: ESP32 publishes readings via MQTT → HiveMQ broker → Spring Boot backend → React dashboard via WebSocket
- 🔴 Control commands: Dashboard sends commands via REST API → backend publishes to MQTT → ESP32 subscribes and acts (including triggering the servo feeder)
Figure 2: Fishmaster Cloud Architecture — ESP32 → HiveMQ → Spring Boot → React
- Monitoring: Tracks Temperature, pH, and Turbidity in real time.
- Feeding: Uses a servo motor (SG90) to dispense food on a set schedule. Feeding is paused automatically if water quality is unsafe (e.g. high turbidity).
- Alerts: Sends a remote notification and sounds a local audible alarm if any water parameter goes outside the safe range.
- Data History: Saves all sensor readings so you can view trends over time.
- Local Display: A 2.8" ILI9341 touch LCD on the device shows live data without needing a computer or internet connection.
- Offline Mode: The device continues monitoring and feeding even when Wi-Fi is unavailable.
| Component | Model / Details | Qty | Purpose |
|---|---|---|---|
| ESP32 | ESP32-DevKitC-32E (38-pin, CP2102) | 1 | Main microcontroller |
| Expansion Board | ESP32 38-pin GPIO Expansion Board (Type-C) | 1 | Easier wiring, stable connections |
| pH Sensor | PH 0–14 Liquid Monitoring Sensor | 1 | Water pH detection |
| Turbidity Sensor | FARDUINO Water Turbidity Module | 1 | Water clarity detection |
| Temperature Sensor | DS18B20 Waterproof Probe | 1 | Water temperature |
| Display | 2.8" ILI9341 SPI Touch LCD (240x320) | 1 | Local UI display |
| Audio Device | Active/Passive Piezo Buzzer / Speaker | 1 | Local audible alerts & notifications |
| Servo Motor | SG90 180° Micro Servo | 1 | Automatic fish feeder |
| Breadboard | MB-102 830-point | 1 | Circuit prototyping |
| Jumper Wires | 140 / 560 pcs set (M-M, M-F, F-F) | 1 set | Circuit connections |
| Resistors | 4.7kΩ (0.25W, 5%) | ~10 | Pull-up for DS18B20 |
| Multimeter | HABOTEST HT109L | 1 | Debugging & testing |
| USB Cable | USB Type-C | 1 | Power & programming |
| Power Supply Module | MB102 Breadboard 5V/3.3V Power Supply Module | 1 | Provides stable power to breadboard |
| Component | Technology / Details | Function |
|---|---|---|
| Backend | Spring Boot (Java) | Receives sensor data via MQTT, processes it, exposes REST API |
| Frontend | React (JavaScript) | Displays dashboard, charts, alerts and feeding controls |
| Database | PostgreSQL | Stores user data, sensor history and feeding logs |
| MQTT Broker | HiveMQ Cloud (Free Tier, QoS 1) | Handles real-time messaging between ESP32 and backend |
Main dashboard view
Sensor data charts
- No authentication (single client setup)
- Some features may not work fully
- Mainly for testing UI and data flow
👉 https://fishmaster.up.railway.app/
- Hardware sensor setup
- Basic backend API
- Dashboard UI
- Support for multiple tanks
- Servo feeder integration
- Audio alert integration
- Condition-based feeding logic
- Support for calibration settings
- Offline/online mode switching