SMCS Pi in the Sky

A Raspberry Pi 4 camera streaming application with servo motor control and brightest pixel detection.

Features

• Live Video Streaming: MJPEG stream accessible at /admin/stream or /admin/stream.mjpeg
• Brightest Pixel Detection: Real-time tracking of the brightest point in the camera feed
• Servo Control: Web-based dashboard for controlling two SM-S4303R continuous rotation servos
• Authentication: Admin pages protected with basic HTTP authentication
• Public API: Unauthenticated endpoint for brightest pixel coordinates

Hardware Requirements

• Raspberry Pi 4
• OV5647 Camera Module (connected via MIPI interface)
• 2x SM-S4303R Continuous Rotation Servos
  • Servo 1: GPIO 17
  • Servo 2: GPIO 27
• Power supply for servos

Software Requirements

• Raspberry Pi OS (Debian Trixie)
• Python 3.9+
• pigpiod daemon (for servo control)

Installation

1. Install System Dependencies

# Update system
sudo apt update && sudo apt upgrade -y

# Install pigpio daemon
sudo apt install pigpio python3-pigpio -y

# Enable and start pigpiod
sudo systemctl enable pigpiod
sudo systemctl start pigpiod

2. Set Up Python Environment

# Navigate to project directory
cd /path/to/smcs-pi-in-the-sky

# Create virtual environment
python3 -m venv venv

# Activate virtual environment
source venv/bin/activate

# Install Python dependencies
pip install -r requirements.txt

3. Configure Authentication

The .env file contains the login credentials in the format:

ADMIN_USERNAME=username
ADMIN_PASSWORD=password

*These are not the actual admin credentials. You can modify these in the .env file if needed.

Usage

Starting the Application

# Make sure pigpiod is running
sudo systemctl status pigpiod

# Activate virtual environment
source venv/bin/activate

# Run the application
python3 app.py

The server will start on http://0.0.0.0:5000

Accessing the Dashboard

1. Open a web browser
2. Navigate to http://<raspberry-pi-ip>:5000/admin/dashboard
3. Enter credentials when prompted

API Endpoints

Public Endpoints (No Authentication Required)

• GET /api/coordinate
  • Returns the (x, y) coordinates of the brightest pixel
  • Example response: {"x": 320, "y": 240}

Admin Endpoints (Authentication Required)

• GET /admin/dashboard

  • Web dashboard with video stream and servo controls

• GET /admin/stream or /admin/stream.mjpeg

  • MJPEG video stream from camera

• POST /admin/servo/control

  • Control servo motors
  • Request body:

    {
      "servo": "servo1",  // or "servo2"
      "pulse_width": 1500  // 500-2500 microseconds
    }

• POST /admin/servo/stop

  • Stop a servo motor
  • Request body:

    {
      "servo": "servo1"  // or "servo2"
    }

Servo Control Guide

The SM-S4303R servos are continuous rotation servos:

• 1500 μs: Stop/Rest position
• < 1500 μs: Clockwise rotation (speed increases as value decreases)
• > 1500 μs: Counter-clockwise rotation (speed increases as value increases)
• Range: 500-2500 microseconds

Experimentally, the best settings for the servos are 1030μs (Servo 1), and 1520μs (Servo 2).

Project Structure

smcs-pi-in-the-sky/
├── app.py                 # Main Flask application
├── camera.py             # Camera management and image processing
├── servo_control.py      # Servo motor control using pigpiod
├── templates/
│   └── dashboard.html    # Admin dashboard interface
├── .env                  # Authentication credentials (not in git)
├── requirements.txt      # Python dependencies
└── README.md            # This file

Troubleshooting

Camera Not Starting

# Check if camera is detected
rpicam-vid --list-cameras

# Check camera interface is enabled
sudo raspi-config
# Navigate to Interface Options > Camera and enable it

Servos Not Responding

# Check if pigpiod is running
sudo systemctl status pigpiod

# Restart pigpiod if needed
sudo systemctl restart pigpiod

# Check GPIO permissions
sudo usermod -a -G gpio $USER

Permission Errors

# Add user to video group for camera access
sudo usermod -a -G video $USER

# Log out and back in for changes to take effect

Development

To run in development mode with debug enabled, modify app.py:

app.run(host='0.0.0.0', port=5000, debug=True, threaded=True)

Security Notes

• Authentication credentials are stored in plain text in .env
• The API endpoint /api/coordinate is intentionally public
• For production use, consider implementing HTTPS and more robust authentication
• Never commit .env to version control

License

This project is created for educational purposes under the MIT license. Made by Eli Ferrara, SMCS class of 2026.