Smart Irrigation

Abstract

1. Introduction

IoT-based automatic irrigation system using STM32F407, ESP8266 WiFi, and environmental sensors with web dashboard control.

2. Objective

IoT-based smart agriculture system using STM32, DHT11, ESP8266 & SIM800L for automated monitoring, irrigation control, and SMS alerts.

This project demonstrates how C can be applied to a real-world Internet of Things (IoT) problem.

3. Key Features / Modules

• Automatic Irrigation: Activates watering when soil humidity ≤ 50%, stops when ≥ 80%
• Manual Override: Remote control via web dashboard
• Real-time Monitoring: Temperature/humidity updates every 2 seconds
• SMS Alerts: Temperature threshold notifications (33°C) with 5-minute cooldown
• Web Dashboard: Live data and controls accessible from any device
• Dual Mode Operation: Seamless AUTO/MANUAL mode switching
• Tested configuration (4.0V): 4.0V × 0.667 = 2.67V Safe for STM32
• With 3.7V Li-Ion: 3.7V × 0.667 = 2.47V Safe for STM32
• With 4.2V (fully charged): 4.2V × 0.667 = 2.80V Safe for STM32

4. Technology Stack

• MCU: STM32F407VGT6 (168MHz ARM Cortex-M4F)
• WiFi: ESP8266 (802.11 b/g/n, 2.4GHz)
• Sensor: DHT11 (0-50°C, 20-90% RH, ±2°C/±5% accuracy)
• Communication: UART, USB CDC, WiFi, MQTT, GSM
• Update Rate: 2-second sensor intervals
• Power: 5V (STM32), 3.3V (ESP8266), 4V (SIM800L)

5. System Requirements

General requirements for this technology stack — check the README for exact versions.

• Arduino IDE / PlatformIO or a C compiler (gcc)
• Target board where applicable
• Git (to clone the repository)

6. Installation & Setup

git clone https://github.com/Yassineg07/smart-irrigation.git
cd smart-irrigation

1. Download from mosquitto.org
2. Install and run as service

sudo apt update
sudo apt install mosquitto mosquitto-clients
sudo systemctl start mosquitto
sudo systemctl enable mosquitto

docker run -d -p 1883:1883 --name mosquitto eclipse-mosquitto

cd websocket
npm install
npm run setup    # Automated configuration script
npm start

cd websocket
npm install
# Edit server.js and replace YOUR_MQTT_BROKER_IP with your broker IP
npm start

Full setup instructions are in the project README.

7. Future Enhancements

Suggested extensions you can add to make this your own project.

• Add a mobile dashboard using Blynk or Firebase
• Store readings in a cloud database for history charts
• Add alerts via SMS / Telegram when thresholds are crossed

8. Viva / Review Questions

Common questions examiners ask for projects in this domain.

1. Which microcontroller / board and sensors are used and why?
2. How does the device send data (Wi-Fi, MQTT, HTTP, Bluetooth)?
3. Where is the sensor data stored and visualised?
4. How is power consumption managed?
5. How would you secure the device and its communication?

9. Source Code & License

This project is developed by Yassineg07 and published on GitHub under the MIT License. Please follow the license terms and credit the original author when you use or modify this code.