CYD Line Bounce

An animated line bouncing demo for the Cheap Yellow Display (CYD) ESP32-2432S028R. This project creates a dynamic screen saver-style animation with bouncing lines that leave colorful trails.

🎯 What It Does

This Arduino sketch animates a line with two endpoints that bounce around the screen, leaving a gradient trail behind it. The animation features:

• Bouncing Physics: Lines bounce off screen boundaries with randomized velocities
• Trail Effect: Smooth gradient trail that fades from blood red to candy apple red
• High Performance: Runs at maximum frame rate with no artificial delays
• Dynamic Movement: Random starting positions and velocity changes on bounces

📺 Watch it in action: CYD Line Bounce Demo

🖥️ Hardware Requirements

• Display: Cheap Yellow Display (CYD) ESP32-2432S028R
• Resolution: 320x240 pixels
• Interface: SPI TFT display
• Microcontroller: ESP32

🎨 Visual Features

Trail System

• 5 Trail Lines: Smooth interpolation between stored positions
• Gradient Colors: Blood red to candy apple red gradient
• Smooth Movement: All trail lines move fluidly with the main line
• Configurable Spacing: Adjustable trail spacing via TRAIL_SPACING

Animation "Physics"

• Random Bounces: Velocity changes randomly on boundary collisions
• Speed Range: Configurable minimum/maximum velocities
• Boundary Detection: Proper collision detection and position correction
• No Sticking: Robust edge handling prevents lines from getting stuck

⚙️ Configuration

Key Parameters

#define TRAIL_LENGTH 5      // Number of trail lines
#define TRAIL_SPACING 3     // Frames between trail position updates
#define VELOCITY_MIN 5      // Minimum bounce velocity
#define VELOCITY_MAX 12     // Maximum bounce velocity
#define FRAME_DELAY 0       // Frame delay (0 = maximum speed)

Color Customization

The trail colors can be easily modified in the trailColors array:

uint16_t trailColors[TRAIL_LENGTH] = {
  0x6000, // Blood red - back trail line
  0xCA0A, // 
  0xFB0F, // 
  0xE004, // 
  0xF840  // Candy apple red - front trail line
};

🚀 Installation

1. Install Libraries: Ensure TFT_eSPI library is installed with the correct User_Setup.h file. I followed this to get my CYD running the first time with Arduino: https://randomnerdtutorials.com/cheap-yellow-display-esp32-2432s028r/
2. Configure TFT_eSPI: Set up the library & display settings in CYD_line_bounce.ino for your specific display
3. Upload Code: Compile and upload to your ESP32
4. Enjoy: Watch the bouncing lines...straight from the 1980's

🔧 Technical Details

Trail System

• Uses circular buffer to store trail positions
• Interpolates between stored positions for smooth movement
• Updates trail positions every TRAIL_SPACING frames
• Handles frame counter overflow protection

Performance

• Runs at maximum hardware speed (no artificial delays)

🎮 Customization

Changing Colors

Modify the trailColors array to create different gradient effects:

• Use RGB565 color format
• Create custom gradients from any color to any color
• Experiment with different color combinations

Adjusting Speed

• Increase Speed: Raise VELOCITY_MAX
• Decrease Speed: Lower VELOCITY_MIN
• Change Trail Density: Modify TRAIL_SPACING

🐛 Known Issues

• The 5th trail line (closest to main line) is currently disabled due to visual inconsistencies
• Some color combinations may not display correctly depending on display configuration
• High speeds may cause occasional visual artifacts

📝 Code Notes

This project was created as a vibe coding experiment with Cursor AI. The code is functional but not optimized for production use. It serves as a rough starting point for TFT display animations and can be extended with additional features.

🤝 Contributing

Feel free to fork this project and experiment with:

• Different trail effects
• Multiple bouncing lines
• Interactive controls
• Sound effects
• Network connectivity features

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Created for the Cheap Yellow Display community - enjoy your bouncing lines! 🎯