When Is One Pixel Cooler Than Millions?

July 9, 2022 by Elliot Williams 14 Comments

On vacation, we went to see a laser show – one of the old school variety that combines multiple different lasers of many different colors together into a single beam, modulates them to create different colors, and sends it bouncing off galvos to the roof of a planetarium. To a musical score, naturally.

When I was a kid, I had no idea how they worked, but laser shows were awesome. As a younger grownup hacker, and after some friends introduced me to the dark arts, I built my own setup. I now know how they work from the deepest innards out, and they are no less awesome. Nowadays, you can get a capable set of galvos and drivers for around a hundred bucks from the far east, it’s fair to say that there’s no magic left, but the awesome still remains.

RGB laser — “laser show” by Ilmicrofono Oggiono

At the same time, lasers, and laser shows, are supremely retro. The most stunning example of this hit me while tearing apart a Casio projector ages ago to extract the otherwise unobtainable brand new 455 nm blue laser diodes. There I was pulling one diode out of an array of 24 from inside the projector, and throwing away the incredibly powerful DSP processor, hacking apart the precision optical path, and pulling out the MEMS DLP mirror array with nearly a million little mirrors, to replace it with two mirrors, driven around by big old coil-of-wire electromagnets. Like a caveman.

But still, there’s something about a laser show that I’ve never seen replicated – the insane color gamut that they can produce. It is, or can be, a lot more than just the RGB that you get out of your monitor. Some of the colors you can get out of a laser (or a prism) are simply beautiful in a way that I can’t explain. I can tell you that you can get them from combining red, blue, green, cyan, and maybe even a deep purple laser.

What you get with a laser show pales in comparison to the multi-megapixel projectors in even a normal movie theater. Heck, you’ve really got one pixel. But if you move it around fast enough, and accompany it with a decent soundtrack, you’ve still got an experience that’s worth having while you still can.

[Banner image from a positively ancient RGB laser hack. We need more! Send us yours!]

The Smallest Large Display Is Projected Straight Onto Your Retina

April 15, 2020 by Maya Posch 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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Fluorescence Microscope On A Hacker’s Budget

March 30, 2019 by Brian McEvoy 19 Comments

Some of biology’s most visually striking images come from fluorescence microscopes. Their brilliant colors on black look like a neon sign from an empty highway. A brand new fluorescence microscope is beyond a hacker’s budget and even beyond some labs’, but there are ways to upgrade an entry-level scope for the cost of a few cups of coffee. [Justin Atkin] of The Thought Emporium published a scope hacking video which can also be seen below. He is becoming a reputed scope modder.

This video assumes a couple of things for the $10 price tag. The first premise is that you already have a scope, a camera adapter, and a camera capable of shooting long exposures. The second premise is that you are willing to break the seals and open the scope to make some reversible mods. Since you are reading Hackaday, maybe that is a given.

The premise is simple compared to the build, which is not rocket surgery, the light source from below illuminates the subject like a raver, and the filter removes any light that isn’t spectacular before it gets to the camera.

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Teardown: AppLights Personalized Projection

February 27, 2019 by Tom Nardi 22 Comments

Listen, it hurts to hear, but somebody needs to say it. It’s over, OK? You’ve got to admit it and move on. Sure, you could get away with it for a week or two in January, but now it’s just getting weird. No matter how hard you fight it, the facts are the facts: the holidays are over. It’s time to pack up all those lights and decorations before the neighbors really start talking.

But don’t worry, because there’s an upside. Retailers are now gearing up for their next big selling season, which means right now clearance racks the world over are likely to be playing home to holiday lights and decor. That wouldn’t have been very interesting to the average hacker or maker a few years ago, after all, there’s only so much you can do with a string of twinkle lights. But today, holiday decorations are dripping with the sort of high-tech features you’d expect from gadgets that are actively aiming to be obsolete within the next ten months or so.

Case in point, the “AppLights Personalized Projection” which I found sulking around the clearance section of the Home Depot a couple weeks back. This device advertises the ability to project multi-color custom messages and animations on your wall, and is configured over Bluetooth with a companion application on your Android or iOS device. At a minimum we can assume the device must contain a fairly powerful RGB LED, an LCD to shine the light through, and some sort of Bluetooth-compatible microcontroller. For $20 USD, I thought it was worth taking a shot on.

Around this time last year, the regular Hackaday reader may recall I did a teardown for a Christmas laser projector. Inside we found red, green, and blue lasers of considerable power, as well as all the optics and support hardware to get them running. It was a veritable laser playground for $14. Let’s see if the AppLights projector turns out to be a similar electronic cornucopia, and whether or not we’ve got a new Hackaday Holiday tradition on our hands.

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Dublin Knows How To Bring-a-Hack

April 9, 2018 by Mike Szczys 11 Comments

When on the road, we love to stop by a local hackerspace and connect with the hacker community. On Friday, TOG Hackerspace in Dublin, Ireland opened their doors to host a Bring-a-Hack with Hackaday and Tindie.

The city center of Dublin is anything but a grid. The cobblestone roads meander every which way and are a puzzle of one-way and surprise construction, none of which seemed to faze Google’s navigation algorithms. I was happy to be operating the smartphone instead of the rental vehicle. A big thanks goes to Jenny List for taking on the stress of driving on our refreshments run without coming in contact with people or cars.

You’re likely wondering why the street layout of the city deserves such attention. I’m used to centrally-located Hackerspaces being tight on space, and indeed the members of TOG cautioned us that 50 people would feel cramped. Much the opposite, the pubs, restaurants, hotels, and performing arts centers are not small, nor winding, nor made of cobblestones. Dublin is a fantastic place to party, with plenty of space for us hardware geeks to congregate. TOG itself, which about 20 minutes walk from the central Temple Bar area (where this image was taken), even has a small parking lot which made our beer drop off and pizza delivery a breeze.

A Tour of TOG Hackerspace

TOG is a Gaelic word which loosely translates as “to make”. Declan met us for the beer drop and gave us a tour when we returned for the evening event. The building is divided into several different spaces, starting with an entry area that serves as a meeting space, gaming room, and showcase of projects.

Where you might see prayer flags strung up on an apartment building, we see floppy disks (both the hard and soft variety) strung around the meeting area. Declan has a shamrock of K’nex parts wired up with a microphone controlled RGB LED strip — it’s like a test your strength game to see who can shout the coolest colors.

3.5″ Floppies

5.25″ Floppies

Sound-activated shamrock

Shamrock is RGB

How would you do on fabric anatomy?

I also really enjoyed the fabric anatomy display that has snaps on each organ and only lights up the labels if you complete the circuits in the correct locations.

These are just the tip of the iceberg. There’s much more after the break so join me for the rest of the tour, and some of the notable hacks that showed up on Friday evening.

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Hackerspacing In Europe: ACKspace In Heerlen

October 23, 2013 by James Hobson 11 Comments

ACKspace group photo

Welcome to the ACKspace in Heerlen. So far this has been one of the coolest hackerspaces we have visited — and super hospitable! What makes this space really neat is the location. It’s on the first floor of a mostly empty office building. They have three official rooms on the first floor. The Hackspace, the Slackspace, and the Stackspace — quite self-explanatory.

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Weekly Roundup 11/12/11

November 12, 2011 by Jack Buffington 1 Comment

In case you missed them the first time around, here are our most popular posts from the past week:

In the #1 spot, we had a post about a tri-color laser projector that really is a well-done project. This projector sweeps the lasers around in vector mode using a pair or mirror galvanometers so would be perfect for playing asteroids in vivid full color!

In at #2 is a post about a PVC pipe gun that can shoot AA batteries at 600 batteries per minute!

Next up we have a post about the US military finding that due to Chinese counterfeit electronics, some of its weapon systems are defective. This has become a more serious issue in recent years. It has effected hackers too as shown in this Sparkfun post from last year.

After that, we had a post about a novel and somewhat scary way to post bulletins on a board without using tacks. How do they do that? By carefully using 20,000 Volts! Yikes. We’ll stick to tape next time we run out of tacks thank you very much.

Finally, we have one about a spot welder built out of some super capacitors and carbon rods. This one probably produces equally large sparks where it is welding and at the triggering mechanism!