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!]

Not On The Internet

July 2, 2022 by Elliot Williams 106 Comments

Whenever you need to know something, you just look it up on the Internet, right? Using the search engine of your choice, you type in a couple keywords, hit enter, and you’re set. Any datasheet, any protocol specification, any obscure runtime error, any time. Heck, you can most often find some sample code implementing whatever it is you’re looking for. In a minute or so.

It is so truly easy to find everything technical that I take it entirely for granted. In fact, I had entirely forgotten that we live in a hacker’s utopia until a couple nights ago, when it happened again: I wanted to find something that isn’t on the Internet. Now, to be fair, it’s probably out there and I just need to dig a little deeper, but the shock of not instantly finding the answer to a random esoteric question reminded me how lucky we actually are 99.99% of the time when we do find the answer straight away.

So great job, global hive-mind of über-nerds! This was one of the founding dreams of the Internet, that all information would be available to everyone anywhere, and it’s essentially working. Never mind that we can stream movies or have telcos with people on the other side of the globe – when I want a Python library for decoding Kansas City Standard audio data, it’s at my fingertips. Detailed SCSI specifications? Check.

But what was my search, you ask? Kristina and I were talking about Teddy Ruxpin, and I thought that the specification for the servo track on the tape would certainly have been reverse engineered and well documented. And I’m still sure it is – I was just shocked that I couldn’t instantly find it. The last time this happened to me, it was the datasheet for the chips that make up a Speak & Spell, and it turned out that I just needed to dig a lot harder. So I haven’t given up hope yet.

And deep down, I’m a little bit happy that I found a hole in the Internet. It gives Kristina and me an excuse to reverse engineer the format ourselves. Sometimes ignorance is bliss. But for the rest of those times, when I really want the answer to a niche tech question, thanks everyone!

Hacker Diary: Embedded World 2022

June 25, 2022 by Elliot Williams 11 Comments

Yesterday I went up to the Embedded World trade fair in Nuremburg, Germany. As a lone hacker, you often feel more than a little out of place when you buy chips in single unit quantities and the people you’re talking to are used to minimum order quantities of a million. But what’s heartening is how, once you ask an interesting question, even some of the suit-wearing types flip into full-on kids who like to explain the fun tech. I struck up conversations with more than a couple VPs of global chip behemoths, and they were cool.

But my heart is still with the smaller players, and the hackers. That’s where the innovation is. I met up with Colin O’Flynn, of Chip Whisperer fame — his company is selling fancier chip-glitching tools, but he still had a refined version of the open source, quick-and-dirty zapper circuit from his Remoticon talk last year. There was a small local company producing virtual buttons that were essentially Pepper’s Ghost illusions floating in mid-air, and the button press was detected by reflective IR. Cool tech, but I forgot the company’s name — sorry!

Less forgettable was Dracula Technologies, a French company making inkjet-printable organic solar cells. While they wouldn’t go into deep details about the actual chemistry of what they’re doing, I could tell that it pained them to not tell me when I asked. Anyway, it’s a cool low-power solar tech that would be awesome if it were more widespread. I think they’re just one of many firms in this area; keep your eyes on organic solar.

When talking with a smaller German FPGA manufacturer, Cologne Chip, about their business, I finally asked about the synthesis flow and was happily surprised to hear that they were dedicated to the fully open-source Yosys toolchain. As far as I know, they’re one of the only firms who have voluntarily submitted their chips’ specs to the effort. Very cool! (And a sign of things to come? You can always hope.)

I met a more than a few Hackaday readers just by randomly stumbling around, which also shows that the hacker spirit is alive in companies big and small. All of the companies have to make demos to attract our attention, but from talking to the people who make them, they have just as much fun building them as you or I would.

And last but not least, I ran into Hackaday regular Chris Gammell and my old boss and good friend Mike Szczys who were there representing the IoT startup Golioth, and trying to fool me into using an RTOS on microcontrollers. (Never say never.) We had an awesome walkaround and a great dinner.

If you ever get the chance to go to a trade show like this, even if you feel like you might be out of your league, I encourage you to attend anyway. You’d be surprised how many cool geeks are hiding in the least likely of places.

[Banner image: Embedded World]

Eyes On The Prize!

April 2, 2022 by Elliot Williams 4 Comments

This year’s Hackaday Prize is off to a roaring start. And that’s fantastic, because this year’s challenge is a particularly important one: reducing mankind’s footprint on the earth through better energy collection, better resource use, and keeping what we’ve already got running a little bit longer. Not only is this going to be the central challenge for the next century, but it’s also a playground for hackers like us.

The first phase, Planet-Friendly Power, is in full swing, and we saw some entries on the first day! Were they cheating? Did they have inside information? Nope! Tons of hackers are working on energy efficient ways to drive their projects all along. If your Raspberry Pi data-logger can run on the fuel of the sun, it’s not only better for the world, but it’s a project that you don’t have to remember to change the batteries on.

We’ve got a challenge on recycling, one on reverse engineering stuff to keep it out of the landfill, and one on environmental monitoring and communications infrastructure. These are all great hacker topics, and showcase how folks like us can do our small parts to keep the world running without running it into the ground.

So all of you out there making mesh networks, optimizing solar projects, hacking open closed IoT networks to keep them from obsolescence, or building plastic-sorting robots, this is your chance to get some money and some recognition for your good work.

Thanks again to our Supplyframe overlords for consistently backing and believing in the purpose of the Hackaday Prize, and also to DigiKey who’s been a sponsor of the Prize many years running! Without them, we wouldn’t be able pull this off.

Hack the planet! (Non-ironically, and literally. And get money for doing it.) Hooray for the Hackaday Prize!

Against The Cloud

February 19, 2022 by Elliot Williams 58 Comments

One of our writers is working on an article about hosting your own (project) website on your own iron, instead of doing it the modern, cloudy-servicey way. Already, this has caused quite a bit of hubbub in the Hackaday Headquarters. Who would run their own server in 2022, and why?

The arguments against DIY are all strong. If you just want to spin up a static website, you can do it for free in a bazillion different places. GitHub’s Pages is super convenient, and your content is version controlled as a side benefit. If you want an IoT-type data-logging and presentation service, there are tons of those as well — I don’t have a favorite. If you want e-mail, well, I don’t have to tell you that a large American search monopoly offers free accounts, for the low price of slurping up all of your behavioral data. Whatever your need, chances are very good that there’s a service for you out there somewhere in the cloud.

And that’s awesome if you only want the service provided. But what if you want to play around? Or learn how it all works under the hood? This is Hackaday!

For instance, you could run your own mail server just for your friends and family. The aforementioned search monopolist will probably flag all of your e-mail as spam, partly because they don’t trust small e-mail providers, and partly because that’s the “m” in monopoly. But if you can get folks to whitelist the addresses, you’ll be in business. And then you open up a world of fun and foolery. You can write hooks to automatically handle mail, or you can create an infinite number of mail accounts, even on the fly as per Spamgourmet, the most awesome anti-spam tool of the last 30 years. Or you can invent your own. Run a mailing list for your relatives. Or do something stupid.

I used to run a service where, when a particular account received an e-mail, the attached photo was pushed up to a website with the subject line as the caption. Instant photo-blog, of the strangest and least secure sort. Getting it running was a few lines of Bash scripting, and an afternoon of fun. Is there a service that does this, already existing in the cloud? Probably. One that allows you a little privacy and doesn’t track your every move? Maybe. But even if there is, would I have learned about sendmail by using this service? Nope!

I hear you saying “security” under your breath, and you’re right. This system was secured by lock made of purest obscurity. But still, in seven years of running the service, nobody guessed the magic e-mail address, not once. Knowledge of the e-mail address was essentially a password, but if I needed extra security I probably could have implemented it in a few lines of Bash anyway. The webpage itself was static HTML, so good luck with that, Hackerman! (The site’s been down for a while now, so you missed your chance.)

If you just want a service, you can be served. But if you want to be a server, a first-class Internet citizen, with your own cloud in the sky, nothing’s stopping you either. And in contrast to using someone else’s computers, running your own is an invitation to play. It’s a big, Internet-connected sandbox. There are an infinity of funny ideas out there that you can implement on your own box, and a lot to learn. If you hack on someone else’s box, it’s a crime. If you hack on your own, it’s a pleasure.

I know it’s anachronistic, but give it a try. (PDF, obscenity, uncorrected typos.) Be your own cloud.

The Real World Strikes Back

February 12, 2022 by Elliot Williams 17 Comments

My son was into “Secret Coders“, a graphic novel series wherein a pair of kids discover and thwart a plot to take over the world by learning to program in the LOGO computer language. When I told him that these “turtle bots” were originally actually real physical things, he wanted one. So we built one out of some nice geared DC motors I had lying around.

A turtle bot has essentially three jobs: move forward in a straight line a controlled distance, turn a given number of degrees, and raise and lower a pen. If you’re already screaming “use stepper motors!” at your screen, well, you’re probably right. But I had these nice Faulhaber/Micromo geared motors with encoders that were just collecting dust in the closet, so I used ’em. And because of that, the robot stumbles on two of its three goals in life — the servo pen lifter works just fine.

Perfectly matched DC motors don’t exist. Of course I knew this, because I’ve built bots with DC motors before. But they’ve all had complex control mechanisms and/or feedback that made it moot. Not here. This bot needs to drive perfectly straight without any lines to guide it or more interesting navigation algorithms.

We spent a good half hour driving it around in not-quite-but-almost squares, tweaking each side’s PWMs, running the motors backwards for short bursts to brake the wheels, and generally trying to map degrees of rotation to milliseconds of motor drive. And you know what, my son enjoyed it. The concepts were simple enough for a second grader, and guessing the right PWM values was like a game. When we finally got it good enough, there was a small celebration.

Of course I know that what it really needs is encoder feedback. I installed those encoder gearmotors on purpose after all. But dealing with quadrature and probably a PID loop to control and sync the two sides is not for my son, at least not for another couple years. (They do learn closed-loop control theory in fourth grade these days, right?) I’ll have to do that all offline some night while he’s sleeping.

But I hope he’ll remember the lessons learned from stabbing at it the naive way. Abstractions are great, but no two motors are ever perfectly alike. You’d think you could just calibrate it out, but the motors differ in driven and coasting behavior, so you’ve got a lot more calibrating to do than you think at first. The real world is tough, and although it’s important to have theory and ideas and abstractions to guide you, you’re going to have to tweak to make it work when the wheels hit the floor. But also that it’s fun to do so, and super rewarding when it finally draws a wonky square.

The Weirdest Hack

February 5, 2022 by Elliot Williams 31 Comments

I was on the FLOSS podcast (for the Episode of the Beast no less!) and we were talking all about Hackaday. One of the hosts, secretly Hackaday’s own Jonathan Bennett in disguise, asked me what the weirdest hack I’d ever seen on Hackaday was. Weird?!?!

I was caught like a deer in headlights. None of our hacks are weird! Or maybe all of them are? I dunno, it certainly depends on your perspective. Is it weird to build a box that makes periodic meowing noises to hid in a friend’s closet? Is it weird to design new and interesting wheels for acrobats to roll themselves around in? Is it weird to want a rainbow-colored USB DIP switch? Is it weird that these are all posts from the last week?

OK, maybe we are a little bit weird. But that’s the way we like it. Keep it weird and wonderful, Hackaday. You’ve got enough normal stuff to do eight hours a day!