LED Bicycle Spoke: POV Wheel Display Build

A bicycle spoke POV (Persistence of Vision) display turns your wheel into a full-colour circular screen. As the wheel spins, a strip of LEDs mounted on the spokes creates patterns, images, and even text visible from the side. It is one of the most eye-catching cycling accessories you can build, and it doubles as a brilliant safety feature for night riding in India.

How Bicycle Spoke POV Works

Same principle as a rotary POV display, applied to a bicycle wheel:

• An LED strip is mounted along one or more spokes
• As the wheel rotates, the LEDs trace circular paths
• By timing LED activation to the wheel’s angular position, patterns form
• A Hall effect sensor detects a fixed magnet once per revolution for synchronisation

Hardware Components

• 8-16 WS2812B LEDs on a small PCB strip
• Arduino Nano or Pro Mini
• Hall effect sensor (A3144) + small magnet on the fork
• 3.7V LiPo battery (500-1000 mAh)
• Boost converter to 5V
• 3D-printed or acrylic mounting bracket

Total cost: Rs.500-1000 per wheel.

Mounting LEDs on Spokes

• Mount the LED strip perpendicular to the spoke, pointing outward
• Secure with zip ties and hot glue — vibration resistance is critical
• Balance the assembly — add a counterweight on the opposite spoke if needed
• For better resolution, mount strips on 2-4 spokes (120/90 degree spacing)

Hall Sensor Synchronisation

The Hall sensor triggers once per revolution when passing the fork-mounted magnet:

volatile unsigned long revTime = 0;
void hallISR() {
  revTime = micros();
}
// In the main loop, calculate delay per pixel column
unsigned long colDelay = (micros()-revTime) / NUM_COLUMNS;

Programming Patterns and Images

• Solid colour ring: All LEDs same colour — simple but highly visible
• Rainbow wheel: Colour changes with angular position
• Text display: Your name or a message readable while cycling
• Patterns: Stars, spirals, hearts, or the Indian flag
• Speed indicator: Change pattern or colour based on cycling speed

Power Supply for Rotating Wheel

• Small LiPo battery mounted at the hub for minimal centrifugal load
• Magnetic charging: use pogo pins or magnetic connector for easy charging without removing the battery
• Runtime: 3-5 hours at moderate brightness with 500 mAh battery

Safety and Visibility Benefits

• LED spoke displays dramatically improve side visibility at night
• Cars approaching from side streets see the illuminated wheel clearly
• Use bright white or red patterns for maximum safety impact
• Add a light sensor to automatically turn on at dusk

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