RGB image from the projector, with human for scale.

RGB Laser Projector Does Colorful Asteroids And Much More

May 6, 2026 by Tyler August 13 Comments

Have you thought about building a galvonometer-based laser projector, but don’t know where to start? There are a lot of resources out there, but you could do worse than to check out [Breq] and [Mia]’s laser vector project, which provides a very well-documented and low-cost starting point. They boast that the most expensive part of the project was the ANSI-certified safety glasses, which shows a dedication to safety we wish more people would show when playing with coherent light.

The rest of the parts — from the galvos to the RGB lasers module with dichoric mirrors to keep everything on the same beamline, to the ESP32 module driving everything — was ordered from AliExpress, and not from the most expensive vendors, either. Considering that, it works remarkably well.

If you’re not playing *Asteroids* on your vector display, why even bother?

Like all DIY laser projectors, this one does vector graphics, sweeping the beam fast enough that the human eye registers crisp, clean lines. Galvonometers, or galvos for short, take analog input, so a DAC is needed — fortunately the ESP32-S2 comes with a pair built in. The custom PCB of course has audio-in for the usual Lissajous lightshow or oscilloscope music, but with an ESP32 as the brains, you can do a lot just inside the projector.

Like what? Well, play Asteroids, for instance, using Wiimote controllers. Project a lovely clock. Render text input in various single-stroke fonts. More to the point, since this is a projector, take arbitrary SVG data and project literally any image you’d like — as long as it doesn’t have too many lines, at least. The galvos in this project are rated at 20,000 points per second, which is not exceedingly fast: they were chosen to meet the budget, not the greatest-possible speed.

More to the point is that this is one of the better-documented projects of this type we’ve seen. [Breq] doesn’t just tell us how to build the projector, but why they designed it that way. We really encourage you to give it a read if you’ve been thinking of getting into this sort of display.

We’ve seen plenty of laser projectors before, most of them producing vector images like this one. If you really must have a raster display, though, that’s also an option. Don’t count out vector images, though — they could even replace your Christmas lights.

Thanks to [CapinRedBeard] for the tip! Remember to send any bright ideas you see to our tips line, coherently lit or no.

Upgraded Raster Laser Projector Goes RGB

September 18, 2024 by Dave Rowntree 10 Comments

We’ve covered a scanning laser project by Ben Make’s Everything last year, and now he’s back with a significant update. [Ben]’s latest project now offers a higher resolution and RGB lasers. A couple of previous versions of the device used the same concept of a rotating segmented mirror synchronised to a pulsed laser diode to create scanlines. When projected onto a suitable surface, the distorted, pixelated characters looked quite funky, but there was clearly room for improvement.

More scanlines and a faster horizontal pixel rate

The previous device used slightly inclined mirrors to deflect the beam into scanlines, with one mirror per scanline limiting the vertical resolution. To improve resolution, the mirrors were replaced with identically aligned mirrors of the type used in laser printers for horizontal scanning. An off-the-shelf laser galvo was used for vertical scanning, allowing faster scanning due to its small deflection angle. This setup is quicker than then usual vector galvo application, as the smaller movements require less time to complete. Once the resolution improvement was in hand, the controller upgrade to a Teensy 4 gave more processing bandwidth than the previous Arduino and a consequent massive improvement in image clarity.

Finally, monochrome displays don’t look anywhere near as good as an RGB setup. [Ben] utilised a dedicated RGB laser setup since he had trouble sourcing the appropriate dichroic mirrors to match available lasers. This used four lasers (with two red ones) and the correct dichroic mirrors to combine each laser source into a single beam path, which was then sent to the galvo. [Ben] tried to find a DAC solution fast enough to drive the lasers for a proper colour-mixing input but ended up shelving that idea for now and sticking with direct on-off control. This resulted in a palette of just seven colours, but that’s still a lot better than monochrome.

The project’s execution is excellent, and care was taken to make it operate outdoors with a battery. Even with appropriate safety measures, you don’t really want to play with high-intensity lasers around the house!

Here’s the previous version we covered, a neat DIY laser galvo using steppers, and a much older but very cool RGB vector projector.

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Laser Galvo Control Via Microcontroller’s DAC

February 15, 2018 by Donald Papp 33 Comments

Mirror galvanometers (‘galvos’ for short) are the worky bits in a laser projector; they are capable of twisting a mirror extremely quickly and accurately. With two of them, a laser beam may be steered in X and Y to form patterns. [bdring] had purchased some laser galvos and decided to roll his own control system with the goal of driving the galvos with the DAC (digital to analog) output of a microcontroller. After that, all that was needed to make it draw some shapes was a laser and a 3D printed fixture to hold everything in the right alignment.

The galvos came with drivers to take care of the low-level interfacing, and [bdring]’s job was to make an interface to translate the 0 V – 5 V output range of his microcontroller’s DAC into the 10 V differential range the driver expects. He succeeded, and a brief video of some test patterns is embedded below.

Continue reading “Laser Galvo Control Via Microcontroller’s DAC” →