Personal projects / Optics & light
RGB laser pointer
A handheld light project with selectable colors, brightness control, and an Arduino-based controller.
Open the numbered review →Controls and internal components
Photos 35–37
An RGB laser pointer I built around an inexpensive module combining red, green, and blue lasers with dichroic mirrors—mirrors that selectively transmit or reflect different colors. A pushbutton turns it on, the yellow dial adjusts intensity, and the black selector offers 12 color and pattern settings, including mixed colors, white, flashing, and sparkle effects.
Another view of the RGB laser-pointer project. I discovered that the inexpensive module’s lasers and combining mirrors were poorly aligned: the colors appeared to meet nearby but separated farther away. It was a useful lesson in how much alignment matters when combining several beams.
The opened assembly shows the laser module, power electronics, and wiring to the controls. I recall adapting the power supply from a small battery-backup unit that used 18650 lithium cells. I modified it to supply power on demand and adapted the laser-driver circuit to accept power and control signals from an Arduino Nano, which coordinated the colors and patterns.