Lumigrids is an LED projector for bicycles, which aims to improve safety during night riding. It projects square grids onto the ground. By observing changes in the grids, the rider can easily comprehend the landforms ahead. Lumigrids can be fixed onto the bicycle’s handlebars. Its power is supplied by either an internal battery or by the rotation of the bicycle’s wheels. It has only one button so that the rider can easily use it while riding. The first press will turn on the power, the second press will change the mode of projection, and holding the button down for two seconds will turn the power off. Lumigrids has three modes with different grid sizes that can be used to adapt to different situations: normal mode (140x180mm), high-speed mode (140x260mm), and team mode (300x200mm).