Autonomous Submarine Relies On Color Detection

May 22, 2026 by Zoe Skyforest 5 Comments

We talk about all kinds of autonomous vehicles here at Hackaday, from aerial drones to rugged rovers. A little less common are the submarine builds, likely due to their technical complexity. That said, though they perhaps benefit most from autonomy given they’re so hard to talk to while underwater. In any case, [Ayman] has built an impressive sub that uses some rudimentary techniques to navigate around while under the surface.

The build uses typical construction techniques for DIY subs of this size, with a clear acrylic tube serving as the body of the craft. It’s carefully sealed to ensure water ingress doesn’t send it to the bottom, using nifty tricks like a magnetic coupling for the prop. Inside, there’s a Raspberry Pi 4, kitted out with an Arducam IMX708 camera with a wide angle lens. It’s joined by a BNO085 inertial measurement unit, along with two BMP280 pressure sensors for keeping track of motion and the sub’s vital signs, while a DRV8833 motor controller runs the main drive motor.

There’s also an ESP32 which helps out with motor and servo control for steering, and ballast control. Sinking and floating the sub is handled with a pair of two ballast tanks constructed out of 5 mL syringes that are driven in and out with high-torque output gear motors. The build uses an antenna buoy so that communication can be maintained with the sub when it’s within a certain range of the surface.

A neat addition to the sub is its autonomous navigation code. [Ayman] whipped up some simple object avoidance routines, which rely on the Raspberry Pi’s camera. The code uses HSV values to track specific colored objects and avoid them, which proves more reliable than RGB as it allows tracking color in a largely brightness-independent manner.

Although we’ve featured other builds that use similar construction techniques, seeing a transparent submarine gliding through the water will always make us think of the incredible Open Source Underwater Glider that won the 2017 Hackaday Prize.

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Scratch Built Subnautica Sub Explores The Pool

August 6, 2020 by Tom Nardi 6 Comments

In Subnautica, players explore an alien underwater landscape with the help of a number of futuristic tools and vehicles. [Robert Cook] found himself particularly enamored with the large submarine you unlock towards the later parts of the game, so much so that he decided to build his own real-life version.

Even though the RC version of the Cyclops [Robert] has designed is only big enough to explore swimming pool sized alien landscapes, it’s by no means a simple build. In fact, the sub’s internal watertight compartment holds an impressive array of electronics and systems that are arguably overkill for what’s essentially a toy. Not that we’re complaining, of course.

Beyond the electronics and a few key components, almost every part of the RC Cyclops has been 3D printed. From the bulkheads that cap off the internal watertight acrylic tube to the hull itself, there’s a lot of plastic aboard this ship. Which might explain why it takes nearly two kilograms of lead weight to get the sub close to neutral buoyancy. From there, a clever ballast tank arrangement made from a syringe and peristaltic pump allow the vehicle to dive and surface on command.

[Robert] is in the process of releasing the STL files for all the submarine’s 3D printed components, and has done an excellent job of documenting the roughly four months he’s spent working on the project in a series of videos on his YouTube channel. The videos contain a wealth of fascinating tips and tricks regarding DIY submersible vehicles, such as selecting the proper radio frequencies for maximum penetration through water and counteracting the permeability of 3D printed parts with a generous coating of epoxy.

Modern RC hardware makes it easier than ever to cobble together a “submarine”, but there’s still something to be said for a project that takes the long way around and actually implements features like a functioning ballast system.

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Retrotechtacular: The Nernst Lamp

June 16, 2020 by Dan Maloney 56 Comments

After dominating the illumination market for more than a century, it’s easy to think of the glowing filament of the standard incandescent lamp as the only way people found to turn electricity into light. But plenty of fertile minds turned out alternative designs, one of which is the fascinating Nernst lamp, which we’d previously never heard of.

If the name sounds familiar, it’s likely through exposure to [Walther Nernst]’s equation for electrochemistry, or for his “New Heat Theorem” which eventually became the Third Law of Thermodynamics. Pal of [Einstein] and eventual Nobel laureate, [Nernst] was also a bit of a tinkerer, and he came up with a design for an incandescent lamp in 1897 that was twice as efficient as carbon-filament lamps. The video below, from the Edison Tech Center, details the design, which used a ceramic “glower rod” that would incandesce when current flowed through it. The glower, though, was not conductive until it was quite hot, so separate heater coils that gave the glower a start on the process were included; these were switched off by a relay built into the base of the lamp once the glower started conducting.

It’s a complicated design, but its efficiency, coupled with a better light spectrum and the fact that it didn’t need a vacuum bulb since the glower wouldn’t oxidize like a carbon or tungsten filament, gave it certain advantages that let it stake out a decent share of the early market for electric illumination. It was even the light source for one of the first facsimile machines. We find it a very clever use of what were at the time exotic materials, and wonder if this could have lead to something like vacuum tubes without the vacuum.

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DIY Arc Light Makes An Unnecessarily Powerful Bicycle Headlight

October 17, 2018 by Dan Maloney 39 Comments

Remember when tricking out a bike with a headlight meant clamping a big, chrome, bullet-shaped light to your handlebar and bolting a small generator to your front fork? Turning on the headlight meant flipping the generator into contact with the front wheel, powering the incandescent bulb for the few feet it took for the drag thus introduced to grind you to a halt. This ridiculous arc-lamp bicycle headlight is not that. Not by a long shot.

We’re used to seeing [Alex] doing all manner of improbable, and sometimes impossible, things on his popular KREOSAN YouTube channel. And we’re also used to watching his videos in Russian, which detracts not a whit from the entertainment value for Andglophones; subtitles are provided for the unadventurous, however. The electrodes for his arc light are graphite brushes from an electric streetcar, while the battery is an incredibly sketchy-looking collection of 98 18650 lithium-ion cells. A scary rat’s nest of coiled cable acts as a ballast to mitigate the effects of shorting when the arc is struck. The reflector is an old satellite TV dish covered in foil tape with the electrodes sitting in a makeshift holder where the feedhorn used to be. It’s bright, it’s noisy, it’s dangerous, and it smokes like a fiend, but we love it.

Mounting it to the front of the bike was just for fun, of course, and it works despite the janky nature of the construction. The neighbors into whose apartments the light was projected could not be reached for comment, but we assume they were as amused as we were.

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Hackaday Links: March 23, 2014

March 23, 2014 by Mike Szczys 9 Comments

[Jack] sent us a link to a Metropolitan Museum of Art video showing off a mechanized desk that plays music and has a ton of hidden compartments. Furniture makers of yore built hidden compartments in furniture all the time. After all, there weren’t credit cards back in the day and you had to keep important documents, cash, and everything else on hand. What strikes us is that this mates woodworking of the highest caliber with precision mechanics.

Before you get rid of that old box spring, ask yourself if you need to store dimensional goods. If you rip off the outer fabric, the network of wire inside makes a reasonable lumber rack.

And since we’re talking trash, we enjoyed seeing this water bottle wire spool minder which [Daniel] sent our way.

You know those portable DVD players you can hang from a headrest to entertain the kids on long trips? Well [John’s] broke, and like chasing the dragon, once you’re hooked on watching videos during car trips there’s no going back. Luckily he was able to throw a Raspberry Pi at the problem. He now has a portable OpenElec XBMC device controlled via a smartphone.

[Jaromir] posted some breakout board footprints that you can use. It’s not the footprints that impress us, but the idea of using them to fill up board space when spinning a new PCB. [Thanks Sarah]

LEGO Gachapon. Need we say more? Okay, truth be told we had to look it up too; Wikipedia says it’s spelled Gashapon. These are coin-operated machines that dispense toys inside of plastic capsules. This one’s made of LEGO and it’s awesome.

[Mikhail] actually built his own ballast resistors for some HeNe laser tubes. This is a bit easier than it might sound at first, as they are much lower power than the tubes used in cutters. But none-the-less an interesting, and successful, experiment.

Hackaday Links: Sunday, April 28th, 2013

April 28, 2013 by Mike Szczys 40 Comments

Another week has gone by and we hope you’ve been happily hacking away in your underground lairs. If not, here’s some inspiration that didn’t quite make it to the front page this week:

[Razr] used a CFL ballast to replace the mechanical one in his fluorescent tube light fixture.

To make the drawers of his workbench more awesome [Rhys] used the faceplates from some servers.

This week saw some changes in the hobby PCB market. Looks like BatchPCB is being sold to OSH Park starting May 1st. [Thanks Brad]

[Rich Olson] shouldn’t have any trouble getting out of bed now that his alarm clock literally shreds cash if he doesn’t shut it off.

We faced the same problem as [Kremmel] when we first got a Raspberry Pi, no USB keyboard. We bought one but he simply hacked his laptop to work. [Thanks Roth]

You may remember that post about a self-propelled snowboard. Here’s a similar project that uses a screw-drive system.

And finally, if you need help reading a quadrature encoder from a microcontroller this lengthy technical post is the place to look.

Water Glider Prototype

August 17, 2012 by Mike Szczys 48 Comments

[Byrel Mitchell] wrote in to share some details on this water glider which he has been working on with his classmates at the Nonlinear Autonomous Systems lab of Michigan Technological University. As its name implies, it glides through the water rather than using propulsion systems typically found on underwater ROVs. The wings on either side of the body are fixed in place, converting changes in ballast to forward momentum.

The front of the glider is at the bottom right of the image above. Look closely and you’ll see a trio of syringes pointed toward the nose. These act as the ballast tanks. A gear motor moves a pinion connected to the syringe plungers, allowing the Arduino which drives the device to fill and empty the tanks with water. When full the nose sinks and the glider moves forward, when empty it rises to the surface which also results in forward movement.

After the break you can find two videos The first shows off the functionality and demonstrates the device in a swimming pool. The second covers the details of the control systems.

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