Light painting, also known as light graffiti, involves taking an image for several seconds or minutes. During this time, the camera captures all the light that enters the lens, even if it doesn’t take place simultaneously. This means that a car’s headlights appear as a line, a twirled LED can appear as an orb, or, as seen in this video, a light on a CNC router can appear to be anything you want.
I've experimented with light painting in the past, and even turning bitmaps into router GCode, but after seeing Matthew Rayfield's dot matrix 3D printer web app, I decided to revisit it.
What I came up with was a new fixture for my CNC router that clamps on with magnets. The device is activated by a button, and in its latest form uses an Arduino Nano to control an RGB LED for: green, red, blue, yellow, and random colors.
Code for the build, along with stl files if you want to print your own are found on GitHub. The vacuum fixture base that it attaches to is found in this separate repository. It's been a fun experiment, and the parts should work most routers running a DeWalt DWP611 router or something of similar size.