Cycle Chaser: Transform Your Bike into a Nighttime Light Show with Raspberry Pi

Bring your nighttime rides to life with the Cycle Chaser, a DIY system that projects dynamic animations onto the road behind you. Powered by a Raspberry Pi and a compact, battery‑operated pico projector, the animation’s speed syncs directly with your pedaling pace, creating a mesmerizing visual trail that speeds up or slows down as you do.

Inspired by a previous project where I built a programmable bike headlight, I expanded the idea into a full‑blown animation platform. The result? A lightweight, modular kit that lets cyclists and hobbyists experiment with creative light displays, all while enjoying the safety and convenience of open‑source tools.

Key hardware components include:

• A battery‑powered pico projector that streams video from the Raspberry Pi.
• A Hall‑effect sensor attached to a magnet on the wheel, detecting each revolution to drive the animation frame‑by‑frame.
• The Raspberry Pi’s GPIO pins, accessed through WiringPi, which allow real‑time interaction between the sensor and the software.

On the software side, the project leverages openFrameworks, a robust C++ toolkit for creative coding. OpenFrameworks supports multiple platforms—Windows, macOS, Linux, iOS, and Android—making it an excellent choice for rapid prototyping. The community’s support for Raspberry Pi simplifies setup, and the familiar Processing‑style syntax helps developers transition smoothly.

With the Hall‑effect sensor, each wheel turn triggers a new frame. For example, at 60 RPM your animation will play at roughly 1 frame per second. Adjust the code to modify frame rates, add new visual effects, or sync multiple lights. Whether you want a fiery trail that intensifies with speed or a ripple of colors that fades when you slow down, the system is fully customizable.

Once you have the hardware assembled and the base code running, I encourage you to experiment. Change the animation assets, tweak the timing logic, or integrate additional sensors. If you’re comfortable with Processing, you’ll find the openFrameworks paradigm intuitive, though a few nuances may require a brief learning curve.

Above all, safety first—ensure the projector’s beam is directed away from other road users and that the setup does not obstruct your vision.

For more details, see the Cycle Chaser project page.