Collaborative Effort Gets Laser Galvos Talking G-Code

July 15, 2022 by 9 Comments

Everyone should know by now that we love to follow up on projects when they make progress. It’s great to be able to celebrate accomplishments and see how a project has changed over time. But it’s especially great to highlight a project that not only progresses, but also gives back a little to the community.

That’s what we’re seeing with [Les Wright]’s continuing work with a second-hand laser engraver. It was only a few weeks ago that we featured his initial experiments with the eBay find, a powerful CO2 laser originally used for industrial marking applications. It originally looked like [Les] was going to have to settle for a nice teardown and harvesting a few parts, but the eleven-year-old tube and the marking head’s galvanometers actually turned out to be working just fine.

The current work, which is also featured in the video below, mainly concerns those galvos, specifically getting them working with G-code to turn the unit into a bit of an ad hoc laser engraver. Luckily, he stumbled upon the OPAL Open Galvo project on GitHub, which can turn G-code into the XY2-100 protocol used by his laser. While [Les] has nothing but praise for the software side of OPAL, he saw a hardware hole he could fill, and contributed his design for a PCB that hosts the Teensy the code runs on as well as the buffer and line driver needed to run the galvos and laser. The video shows the whole thing in use with simple designs on wood and acrylic, as well as interesting results on glass.

Of course, these were only tests — we’re sure [Les] would address the obvious safety concerns in a more complete engraver. But for now, we’ll just applaud the collaboration shown here and wait for more updates.

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Laser Galvos And An ESP32 Recreate Old-School Asteroids

February 18, 2021 by 21 Comments

Playing Asteroids now isn’t quite what it used to be when it came out 40 years ago. At the time, the vector-scan display was part of the charm; making do with an emulator running on a traditional raster display just doesn’t quite do it for purists. But if you manage to build your own laser-projector version of the game like [Chris G] did, you’re getting close to capturing some of the original magic of the game.

There’s a lot to unpack about this project, and the video below does a good job explaining it. Where the original game used a beam of electrons flashing inside a CRT to trace out each object in the game, [Chris] substituted an off-the-shelf two-axis galvanometer from eBay and a 5-mW laser LED. This can project a gamefield on a wall up to two meters on a side, far bigger than any version of the machine ever built. The galvos are driven by op-amp drivers and an SPI DAC on a custom PCB. And in comparison to the discrete logic chips and 6502 running the original game, [Chris] opted for an ESP32.

As interesting as the hardware for this is, the real story is in the software. [Chris] does an excellent job running through his design, making the bulk of the video feel like a master class in game programming. His software is from scratch — no emulations here. As such it doesn’t perfectly reproduce the original games — no flying saucers and no spaceship explosion animations (yet) — but when coupled with the laser vector display, it certainly captures the feel of the original.

Being devoted Asteroids fans from back in the day, this one really pushes our buttons. We’ve seen laser-based recreations of the game before, but this one makes us think we can finally afford to recapture the glory of our misspent youth.

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Laser Galvo Control Via Microcontroller’s DAC

February 15, 2018 by 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.

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Custom built RGB laser firing beam

Lasers, Galvos, Action: A Quest For Laser Mastery

November 22, 2024 by 1 Comment

If you’re into hacking hardware and bending light to your will, [Shoaib Mustafa]’s latest project is bound to spike your curiosity. Combining lasers to project multi-colored beams onto a screen is ambitious enough, but doing it with a galvanomirror, STM32 microcontroller, and mostly scratch-built components? That’s next-level tinkering. This project isn’t just a feast for the eyes—it’s a adventure of control algorithms, hardware hacks, and the occasional ‘oops, that didn’t work.’ You can follow [Shoaib]’s build log and join the journey here.

The nitty-gritty is where it gets fascinating. Shoaib digs into STM32 Timers, explaining how modes like Timer, Counter, and PWM are leveraged for precise control. From adjusting laser intensity to syncing galvos for projection, every component is tuned for maximum flexibility. Need lasers aligned? Enter spectrometry and optical diffusers for precision wavelength management. Want real-time tweaks? A Python-controlled GUI handles the instruments while keeping the setup minimalist. This isn’t just a DIY build—it’s a work of art in problem-solving, with successes like a working simulation and implemented algorithms along the way.

If laser projection or STM32 wizardry excites you, this build will inspire. We featured a similar project by [Ben] back in September, and if you dig deep into our archives, you can eat your heart out on decades of laser projector projects. Explore Shoaib’s complete log on Hackaday.io. It is—literally—hacking at its most brilliant.

Upgraded Raster Laser Projector Goes RGB

September 18, 2024 by 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 Fault Injection On The Cheap

August 9, 2024 by 8 Comments

One can only imagine the wonders held within the crypto labs of organizations like the CIA or NSA. Therein must be machines of such sophistication that no electronic device could resist their attempts to defeat whatever security is baked into their silicon. Machines such as these no doubt bear price tags that only a no-questions-asked budget could support, making their techniques firmly out of reach of even the most ambitious home gamer.

That might be changing, though, with this $500 DIY laser fault injection setup. It comes to us from Finnish cybersecurity group [Fraktal], who have started a series of blog posts detailing how they built their open-source reverse-engineering rig. LFI is similar to other “glitching” attacks we’ve covered before, such as EMP fault injection, except that a laser shining directly on a silicon die is used to disrupt its operation rather than a burst of electromagnetic energy.

Since LFI requires shining the laser very precisely on nanometer-scale elements of a bare silicon die, nanopositioning is the biggest challenge. Rather than moving the device under attack, the [Fraktal] rig uses a modified laser galvanometer to scan an IR laser over the device. The galvo and the optical components are all easily available online, and they’ve started a repo to document the modifications needed and the code to tire everything together.

Of course, this technique requires the die in the device under study to be exposed, but [Fraktal] has made that pretty approachable too. They include instructions for milling away the epoxy from the lead-frame side of a chip, which is safer for the delicate structures etched into the top of the die. The laser can then shine directly through the die from the bottom. For “flip-chip” packages like BGAs, the same milling technique would be done from the top of the package. Either way, we can imagine a small CNC mill making the process safer and quicker, even though they seem to have done pretty well with a Dremel.

This looks like a fantastic reverse engineering tool, and we’re really looking forward to the rest of the story.
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An RGB laser projector opened up on a workbench

Laser Projector Needs Hardware Hack After Software Mod

December 11, 2022 by 13 Comments

You probably recognize that dreadful feeling when you reboot a gadget after updating its firmware, only to be greeted by a blank screen and an unresponsive device. This apparently happened to the previous owner of a bricked RGB laser projector that [Buy It Fix It] got his hands on: it briefly flashed its laser on power-up but otherwise remained completely dead.

A thorough inspection of the major components didn’t reveal any physical damage, so the issue had to be in software. [Buy It Fix It] managed to connect his Segger J-link programmer to the STM32 main processor and downloaded the contents of its firmware, only to find the remains of a PDF file which seemed to have been accidentally flashed into the chip’s program space. Fixing the device should then just be a matter of restoring the proper firmware, but [Buy It Fix It] wasn’t able to find a copy of it anywhere.

A PCB with a few mod wires on itWhat he did find was Maximus64’s GitHub repository that contained a software mod for a different projector model, as well as its original firmware. Flashing that version didn’t fix [Buy It Fix It]’s projector either, although it did now start to actuate its galvos.

A bit of reverse engineering revealed that the two projectors were very similar from a hardware point of view, but had their laser drivers hooked up to different I/O pins: simply cutting the board traces and soldering some wires to re-route the signals was enough to bring the projector back into a working state.

Having to modify hardware in order to make it fit a piece of software is unfortunate, but sometimes you just have to make do with what you’ve got. If you’ve got no firmware to begin with, then you might even have to write your own from scratch.

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