Laser Hacks

652 Articles

The Smallest Large Display Is Projected Straight Onto Your Retina

April 15, 2020 by 42 Comments

For most of human history, the way to get custom shapes and colors onto one’s retinas was to draw it on a cave wall, or a piece of parchment, or on paper. Later on, we invented electronic displays and used them for everything from televisions to computers, even toying with displays that gave the illusion of a 3D shape existing in front of us. Yet what if one could just skip this surface and draw directly onto our retinas?

Admittedly, the thought of aiming lasers directly at the layer of cells at the back of our eyeballs — the delicate organs which allow us to see — likely does not give one the same response as you’d have when thinking of sitting in front of a 4K, 27″ gaming display to look at the same content. Yet effectively we’d have the same photons painting the same image on our retinas. And what if it could be an 8K display, cinema-sized. Or maybe have a HUD overlay instead, like in video games?

In many ways, this concept of virtual retinal displays as they are called is almost too much like science-fiction, and yet it’s been the subject of decades of research, with increasingly more sophisticated technologies making it closer to an every day reality. Will we be ditching our displays and TVs for this technology any time soon?

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LIDAR Built On Familiar Platform

April 11, 2020 by 7 Comments

Moore’s law may have reached its physical limit for transistor density, but plenty of other technologies are still on that familiar path of getting smaller and smaller as time passes. It looks like LIDAR is no exception to this trend either. This project from [Owen] shows a fully-functional LIDAR system for about $20 and built almost entirely on top of an ESP32.

The build uses a Time-Of-Flight IR laser range sensor controlled by the ESP32, and the sensor is much smaller than even the ESP32’s footprint so it takes up very little extra space. To get it to function as a LIDAR system instead of just a simple rangefinder it does need a motor in order to rotate itself to see its entire space. Besides its small form factor and low cost, it also has a handy user interface that can run anywhere an HTML5 browser can run, making the use of the system easy and straightforward as well. All of the code is available on the project’s GitHub page.

We wouldn’t expect a system like this to be driving an autonomous car anytime soon, it’s update rate is far too slow, but its intent for small robots and even as an educational demo for learning LIDAR is second to none. If you do need a little more power in a LIDAR system but still don’t want to break the bank, we featured this impressive setup a few weeks ago.

LIDAR System Isn’t Just A Rangefinder Anymore

March 24, 2020 by 15 Comments

For any project there’s typically a trade-off between quality and cost,as higher quality parts, more features, or any number of aspects of a project can drive its price up. It seems as though [iliasam] has managed to avoid this paradigm entirely with his project. His new LIDAR system knocks it out of the park on accuracy, sampling, and quality, and somehow manages to only cost around $114 in parts.

A LIDAR system works by sending out many pulses of light in different directions, measuring the reflections of that light as it returns. LIDAR systems therefore improve with higher frequency pulses and faster control electronics for both the laser output and the receiving data. This system manages to be accurate to within a few centimeters and works up to 25 meters all while operating at 15 scans per second. The key was a high-powered laser module which can output up to 75 watts for extremely short times. More details can be found at this page (Google Translate from Russian).

Another bonus from this project is that [iliasam] has made everything available from his GitHub page including hardware specifications, so as long as you have a 3D printer this won’t take long to produce either. There’s even detailed breakdowns of how the laser driving circuitry works, and how there are safety features built in to keep anyone’s vision from accidentally getting damaged. Needless to say, this isn’t just a laser rangefinder module but if you want to see how you can repurpose those, [iliasam] can show you that as well.

Camera And Code Team Up To Make Impossible Hovering Laser Effect

March 5, 2020 by 20 Comments

Right off the bat, we’ll say that this video showing a laser beam stopping in mid-air is nothing but a camera trick. But it’s the trick that’s the hack, and you’ve got to admit that it looks really cool.

It starts with the [Tom Scott] video, the first one after the break. [Tom] is great at presenting fascinating topics in a polished and engaging way, and he certainly does that here. In a darkened room, a begoggled [Tom] poses with what appears to be a slow-moving beam of light, similar to a million sci-fi movies where laser weapons always seem to disregard the laws of physics. He even manages to pull a [Kylo Ren] on the slo-mo photons with a “Force Stop” as well as a slightly awkward Matrix-style bullet-time shot.  It’s entertaining stuff, and the effect is all courtesy of the rolling shutter effect. The laser beam is rapidly modulated in sync with the camera’s shutter, and with the camera turned 90 degrees, the effect is to slow down or even stop the beam.

The tricky part of the hack is the laser stuff, which is the handiwork of [Seb Lee-Delisle]. The second video below goes into detail on his end of the effect. We’ve seen [Seb]’s work before, with a giant laser Asteroids game and a trick NES laser blaster that rivals this effect.

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Star Wars Themed Laser Badge: All That Is Missing Is The Pew Pew Sound Effect

February 13, 2020 by 9 Comments

In the quest to advance the art of the electronic badge, the boundaries of what is possible to manufacture in small quantities are continually tested. Full-colour PCBs, injection moulding, custom keyboards, and other wow factor techniques have all been tried, leading to some extremely impressive creations. With all this innovation then it’s sometimes easy to forget that clever design and a really good idea can produce an exceptional badge with far more mundane materials.

The 10th InCTF cybersecurity contest held at Amrita, Kerala, India, had a Star Wars themed badge designed by Team bi0s for the event. It takes the form of a Millennium Falcon-shaped PCB, with a NodeMCU ESP8266 board mounted on it, a shift register, small OLED display, and the usual array of buttons and LEDs. The fun doesn’t stop there though, because it also packs a light-dependent resistor and a laser pointer diode that forms part of one of its games. Power for this ensemble comes courtesy of a set of AA cells on its underside.

They took a novel approach to the badge’s firmware, with a range of different firmwares for different functions instead of all functions contained in one. These could be loaded through means of a web-based OTA updater. Aside from a firmware for serial exploits there was an Asteroids game, a Conway’s Game Of Life, and for us the star of the show: a Millennium Cannon laser-tag game using that laser. With this, attendees could “shoot” others’ LDRs, with three “hits” putting their opponent’s badge out of action for a couple of minutes.

Unusually this badge is a through-hole design as a soldering teaching aid, but its aesthetics do not suffer for that. We like its design and we especially like the laser game, we look forward to whatever next Team bi0s produce in the way of badges.

This isn’t the first badge packing a laser we’ve seen, at last year’s Def Con there was a laser synth badge. No laser tag battles though.

A Laser Drawing Machine For Flashes Of Creativity

February 7, 2020 by 6 Comments

Ahh, midterms. Some students blow off steam between study sessions by playing video games or just zoning out. While those kids were all distracted, [Justinwong777] and his buddy [Brett] found a bunch of scrap wood and built this laser drawing machine in their school’s makerspace. You operate it as you might an Etch-a-Sketch, except your drawings are as fleeting as sparkler art on the 4th of July, if they made Tron-colored sparklers.

Though you work it like an Etch-a-Sketch, the business end operates like a laser cutter. Inside that plywood enclosure is an Arduino Uno and a pair of motors. These motors turn a series of custom gears, which move a small mirror angled at 45° in the xy-plane.  There’s a 30mW laser mounted parallel with the base, pointed at the mirror, and it reflects the beam toward a canvas panel coated with phosphorescent paint. We dig the printed ergonomic case for the joystick, which gives control of both x and y. Put on some eye protection and check it out after the break.

If you want to draw with lasers, but aren’t much of an artist, do something unexpected: build a laser turret not to kill, but to draw the weather on the wall.

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Node-RED Laser Shooting Gallery Goes Anywhere

January 14, 2020 by 6 Comments

When you think of a shooting gallery, you might envision a line of tin cans set up along a split-rail fence, or a few rows of ducks or bottles lined up at a carnival. But what do these have in common? You, standing in one spot, and shooting in the same general direction. You’re exposed! If those targets could shoot back, you’d be dead within seconds. Wouldn’t it be more fun if the targets were all around you in 360°? We think so, too.

So how could you possibly set up a shooting gallery this way? [Another Maker] already solved that problem for you with ESP32s and Node-RED (YouTube). Each target has an ESP32, a laser sensor, and an LED that lights up when the target is ready, and turns off once it’s been hit. They all make an enticing ‘shoot me’ sound that goes with their graphics, and a second mp3 plays upon direct hit.

The PVC gun houses an ESP8266, a laser module at the end of the barrel, and runs on a cylindrical USB battery slipped down in the secondary grip. [Another Maker] can spread the targets out far and wide, as long as they all stay in range of the localized WiFi access point.

The best part is that the Node-RED system is target-agnostic — it doesn’t care how many you have or how they’re made, and it can juggle up to 250 of them. Because of the way the target objects are programmed, it would be quite easy to add actuators that make them drop down or fall backward when hit. You could also implement [Another Maker]’s fantastic suggestion of hitting arcade buttons with NERF darts instead. Charge those lasers and fire at the break button to see the demo and walk-through video.

If you plan to knock the targets down or over in your implementation, you’ll want an easy way to reset them. Here’s a scrap-built shooting gallery that uses a windshield wiper motor to set ’em back up.