Many people around the world live in cities designed for cars, with bicycle use being a distant afterthought. That makes cycling dangerous and lights can do a lot to make riding safer. That’s why Giovanni Aggiustatutto designed this DIY system that includes headlights, a taillight, turn signals, and even an integrated odometer/speedometer. 

Aggiustatutto wanted this system to work with most bicycles, so he designed the front lights and controls to clamp onto the handlebars. The rear light pod attaches to a cargo rack and should be compatible with a wide range of models. There are two bright white LED headlight arrays on the front with integrated yellow turn signal LEDs. Also on the front is an OLED display that shows the speed, time, and odometer, as well as three buttons. The back lights consist of red taillight LEDs and yellow turn signal LEDs in a single 3D-printed enclosure.

An Arduino Nano board controls everything, directing power to the LEDs from an 18650 lithium battery through IRFZ44N MOSFETs. A DS3231 RTC module helps the Arduino track time accurately and that gives it the ability to monitor speed — and therefore total distance — with the help of a Hall effect sensor. That sensor detects the passing of a magnet attached to a spoke, so the Arduino can count each rotation. The Arduino then displays the results on a 0.96” 128×64 monochrome OLED screen. 

Finally, Aggiustatutto tucked the Arduino and battery into an enclosure disguised as a water bottle to prevent theft.