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ES2C6-Solar-Tracker

This is a solar tracker repository for the ES2C6 course. This project includes two distinct Arduino implementations to demonstrate and compare different solar tracking strategies.

1. Simple LDR: A pure "active" tracker that uses four LDRs (Light Dependent Resistors) to find the brightest light source.
2. Advanced Hybrid + Web UI Tracker: A "hybrid" tracker that uses an Arduino R4 WiFi to fetch precise UTC time, calculate the sun's astronomical position (azimuth/elevation), and then uses LDRs for fine-tuning. It also hosts a modern Web UI for status monitoring.

Circuit

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1. Simple LDR LED Tracker

This is a classic "active" solar tracker. It doesn't care about time or location; it only cares where the light is coming from.

✨ Features

• Active Tracking: Purely based on the difference in readings from the four LDRs to move the servos, always pointing towards the brightest direction.
  • Solar panel voltage
  • Raw readings of the 4 LDRs
  • Current servo angles (Horizontal/Vertical)
  • Average light intensity
• Startup Scan: Executes a findMaxLightPosition() function on boot, scanning the sky (0-180 degrees) to find the initial brightest spot.
• Voltage Monitoring: Optionally connect a small solar panel to pin A4 to monitor its output voltage.

🛠️ Hardware Requirements

• Arduino Uno / Nano (or any compatible board)
• 2x Servo Motors (for Pan/Tilt)
• 4x LDRs (Light Dependent Resistors)
• 4x Pull-down Resistors (e.g., 10KΩ)
• 1x Small Solar Panel (for A4 pin reading)
• 2-axis Pan/Tilt bracket
• Breadboard and jumper wires

📚 Library Dependencies

• Servo
• Adafruit_SSD1306
• Adafruit_GFX

🔧 Setup and Usage

1. Download the code into the Codes/sdynamic_Step/ folder.
2. Open sdynamic_Step.ino in the Arduino IDE.
3. Install the Adafruit_SSD1306 and Adafruit_GFX libraries using the Library Manager.
4. Check Pins: Ensure your OLED and servo pin definitions match the #define section at the top of the code.
   • OLED (SPI): OLED_MOSI, OLED_CLK, OLED_DC, OLED_CS, OLED_RESET
   • Servos: 5 (horizontal), 6 (vertical)
   • LDRs: A0 (TL), A1 (TR), A2 (BL), A3 (BR)
   • Solar Panel: A4
5. Upload the code to your Arduino.
6. When the device boots, it will first perform a "find max light" scan. The OLED will then light up with real-time data, and the tracker will begin active tracking.

Demo

• not assembled
  

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2. Advanced Hybrid + Web UI Tracker

This version uses an Arduino R4 WiFi board, combining time-based predictive tracking with LDR-based corrective tracking.

✨ Features

• Hybrid Tracking:
  • Predictive: Connects to worldtimeapi.org to get UTC time and accurately calculates the sun's Azimuth and Elevation based on a given Latitude and Longitude.
  • Corrective: Uses a 4-quadrant LDR sensor array to fine-tune the calculated position, compensating for any misalignments or atmospheric effects.
• Web Console: Hosts a web server that provides a modern, responsive dashboard built with Tailwind CSS.
• Solunar API: Fetches the day's sunrise, sunset, and solar noon times from api.sunrise-sunset.org.
• Night Mode: Automatically enters "Night Mode" when the sun's elevation is below a threshold (e.g., after sunset), moving the servos to a preset night position (e.g., facing east, ready for sunrise).
• WiFi Management: Automatically attempts to reconnect to WiFi if the connection is lost.

🛠️ Hardware Requirements

• Arduino R4 WiFi
• 2x Servo Motors (for Pan/Tilt)
• 4x LDRs (Light Dependent Resistors)
• 4x Pull-down Resistors (e.g., 10KΩ)
• 2-axis Pan/Tilt bracket
• Breadboard and jumper wires

📚 Library Dependencies

• WiFiS3
• ArduinoJson
• Servo

🔧 Setup and Usage

1. Download the code into the Codes/Dynamic_Step_wtih_Website/ folder.
2. Open dynamic_Step_wtih_Website.ino in the Arduino IDE.
3. Install the required libraries using the Library Manager.
4. Crucial Configuration: Modify the constants at the top of the sketch:
   • WIFI_SSID: Your WiFi network name.
   • WIFI_PASS: Your WiFi password.
   • LATITUDE: Your geographic latitude (e.g., 52.378753f).
   • LONGITUDE: Your geographic longitude (e.g., -1.570225f).
5. Upload the code to your Arduino R4 WiFi.
6. Open the Serial Monitor (Baud Rate: 115200) to view the connection status and the IP address.
7. On a device on the same network, open a web browser and navigate to that IP address (e.g., http://192.168.31.166) to see the web console.

Demo

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💡 How It Works

Active Tracker (Simple)

This model uses a simple Feedback Loop:

1. Compare the average of the top LDRs vs. the average of the bottom LDRs (diffVertical).
2. Compare the average of the left LDRs vs. the average of the right LDRs (diffHorizontal).
3. If the vertical difference is greater than the tolerance, move the vertical servo up or down.
4. If the horizontal difference is greater than the tolerance, move the horizontal servo left or right.
5. This process repeats, constantly minimizing the LDR differences to stay pointed at the light source.

Hybrid Tracker (Advanced)

This model uses a Predict-Correct loop:

1. Predict (Every 10 seconds): The device gets the precise time from an API and uses the solarPositionUTC function to calculate the sun's theoretical position in the sky (azimuth/elevation).
2. Correct (Every 50 milliseconds):
   • The LDRs read the light differential (azDiff, elDiff).
   • The new target position for the servo is a combination of (LDR correction) + (a gentle pull towards the theoretical position).
   • currentPan += deltaPan + SOLAR_CORRECTION_RATE * (targetPanFromSolar - currentPan);
   • This ensures the tracker not only points accurately at the sun (LDR part) but also knows where the sun should be, even after it's temporarily hidden by clouds (time-based part).

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🎉 Acknowledgements / Group Members

This project was a collaborative effort for the ES2C6 module, and the successful outcome is a result of the dedicated work of the entire team. We extend our sincere thanks to the following members:

Name	Assigned Role
Monteiro, Marcus	Background Research
Zhao, Haoxiang Owen	Mechanical Design and CAD Work
Jackson, Josh	Electronic Design
Stephan, Freddy	Manufacture of Mechanical Components and Electronic Circuit Boards
Maini, Rohan	Assembly
Boyu Zhang Bob (me)	Programming and Testing
Charusirisawad, Pun	Overall Project Management and Assigned Task Lead

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📄 License

This project is licensed under the MIT License. You should add a LICENSE file to your repository.