LED Light For Bikes To Improve Visibility

The core of this bicycle visibility system is the Digispark ATtiny85 microcontroller board, which acts as the central processing unit to control the lighting modes. Power is supplied by a 9V USB rechargeable battery connected via a 2-pin connector, with a 220µF electrolytic capacitor placed across the power rails to help stabilize voltage fluctuations. To drive the high-power 1-watt star white LEDs safely without overloading the microcontroller's limited digital output current capacity, an IRL520N N-channel MOSFET is employed as an electronic switch. The ATtiny85 sends control signals to the gate of the MOSFET, utilizing a 10k resistor as a pull-down and a 100-ohm resistor for gate current limiting to protect the I/O pins from high inrush currents caused by MOSFET gate capacitance. A 10k potentiometer is integrated into the circuit as an analog input device, allowing the microcontroller to read varying voltage levels and dynamically adjust the operational state between a steady beam and an adjustable strobe lighting pattern.

Mounted on bicycles as a headlight to ensure the rider is visible to other vehicles and pedestrians at night or in foggy conditions, while also providing enough illumination to see obstacles on the road.