Author: Bryan Cockfield

1827 Articles

Hang Ten With Help From The Surf Window

October 24, 2019 by 6 Comments

Unless you live in a special, unique place like Hawaii or Costa Rica it’s unlikely you’ll be able to surf every day. It’s not easy to plan surf sessions or even surf trips to most locations because the weather conditions will need to be just right. Not only the wave height (swell) but also the wind speed and direction, tide, water and air temperature, and even amount and type of marine life present can all impact your surf session. You’ll want something which can easily tell you right away if conditions are good.

This project from [luke] is called the Surf Window shows the surf conditions at the local beach with just one glance. Made out of various pieces of wood, each part represents one of the weather conditions at the beach. A rotating seagull gives the wind direction, for example, and the wave height is represented by 3D, moving waves. All of the parts are connected with various motors and linkages to an Arduino Mega +WiFi R3 which grabs all of its information from Magicseaweed, a surf forecasting site.

The Surf Window can show the current conditions at virtually any surfable beach in the world, so if you really want to know how Jaws, Mavericks, or even Reef Road is breaking right now, you could use this to give you a more nuanced look. Don’t forget to take the correct board for the conditions!

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Student-Built Rocket Engine Packs A Punch

October 24, 2019 by 30 Comments

A group of students at Boston University recently made a successful test of a powerful rocket engine intended for 100km suborbital flights. Known as the Iron Lotus (although made out of mild steel rather than iron), this test allowed them to perfect the timing and perfect their engine design (also posted to Reddit) which they hope will eventually make them the first collegiate group to send a rocket to space.

Unlike solid rocket fuel designs, this engine is powered by liquid fuel which comes with a ton of challenges to overcome. It is a pressure-fed engine design which involves a pressurized unreactive gas forcing the propellants, in this case isopropanol and N2O, into the combustion chamber. The team used this design to produce 2,553 lb*ft of thrust during this test, which seems to be enough to make this a class P rocket motor. For scale, the highest class in use by amateurs is class S. Their test used mild steel rather than stainless to keep the costs down, but they plan to use a more durable material in the final product.

The Boston University Rocket Propulsion Group is an interesting student organization to keep an eye on. By any stretch of the imagination they are well on their way to getting their rocket design to fly into space. Be sure to check out their other projects as well, and if you’re into amateur rocketry in general there are a lot of interesting things you can do even with class A motors.

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A Drone Sprouts Wings

October 21, 2019 by 5 Comments

While there are some fixed-wing drones in the hobby world, most of us around here think of the quadcopter when this word is mentioned. There have been some fixed-wings around, and lots of multi-rotors, but not much of a mix of the two. [Paweł] wanted to see what would happen if he mixed these two together, and created a quadcopter drone with retractable wings, essentially just to see what would happen.

This isn’t something that can convert from fixed-wing flight to helicopter-style hovering like a V22 Osprey or Harrier, either. The lift and thrust is entirely generated by the rotors, and the “wings” are essentially deployable air brakes that allow the drone to slow down quickly without consuming as much energy under propeller power alone. The air brake wings are designed to automatically deploy as a function of throttle position, too, so there’s a lot that could be built on this idea in the future, in theory.

[Paweł] notes that this design is somewhat controversial, and although few of us are in the drone racing community we can imagine how a functional change like this might impact in an arena such as that. He also only saw marginal performance increases and isn’t planning on perusing this idea much further. If you’re interested in a drone with “true” wings, though, check out this one which gets fired out of a grenade launcher.

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A Tamagotchi For WiFi Cracking

October 16, 2019 by 8 Comments

OK, let’s start this one by saying that it’s useful to know how to break security measures in order to understand how to better defend yourself, and that you shouldn’t break into any network you don’t have access to. That being said, if you want to learn about security and the weaknesses within the WPA standard, there’s no better way to do it than with a tool that mimics the behavior of a Tamagotchi.

Called the pwnagotchi, this package of artificial intelligence looks for information in local WiFi packets that can be used to crack WPA encryption. It’s able to modify itself in order to maximize the amount of useful information it’s able to obtain from whatever environment you happen to place it in. As an interesting design choice, the pwnagotchi behaves like an old Tamagotchi pet would, acting happy when it gets the inputs it needs.

This project is beyond a novelty though and goes deep in the weeds of network security. If you’re at all interested in the ways in which your own networks might be at risk, this might be a tool you can use to learn a little more about the ways of encryption, general security, and AI to boot. Of course, if you’re new to the network security world, make sure the networks you’re using are secured at least a little bit first.

Thanks to [Itay] for the tip!

Extreme Refurbishing: Amiga Edition

October 11, 2019 by 17 Comments

The last Amiga personal computer rolled off the assembly line in 1996, well over 20 years ago. Of course, they had their real heyday in the late 80s, so obviously if you have any around now they’ll be in need of a little bit of attention. [Drygol] recently received what looks like a pallet of old Amiga parts and set about building this special one: The Vampiric Amiga A500.

The foundation of this project was a plain A500 with quite a bit of damage. Corrosion and rust abounded inside the case, as well as at least one animal. To start the refurbishment, the first step was to remove the rust from the case and shields by an electrochemical method. From there, he turned his attention to the motherboard and removed all of the chips and started cleaning. Some of the connectors had to be desoldered and bathed in phosphoric acid to remove rust and corrosion, and once everything was put back together it looks almost brand new.

Of course, some other repairs had to be made to the keyboard and [Drygol] put a unique paint job on the exterior of this build (and gave it a name to match), but it’s a perfect working Amiga with original hardware, ready to go for any retrocomputing enthusiast. He’s no stranger around here, either; he did another extreme restoration of an Atari 800 XL about a year ago.

Professional Audio On An ESP32

October 6, 2019 by 53 Comments

Audiophiles have worked diligently to alert the rest of the world to products with superior sound quality, and to warn us away from expensive gimmicks that have middling features at best. Unfortunately, the downside of most high quality audio equipment is the sticker price. But with some soldering skills and a bit of hardware, you can build your own professional-level audio equipment around an ESP32 and impress almost any dedicated audiophile.

The list of features the tiny picoAUDIO board packs is impressive, starting with a 3.7 watt stereo amplifier and a second dedicated headphone amplifier. It also has all of the I/O you would expect something based on an ESP32 to have, such as I2S stereo DAC, an I2S microphone input, I2C GPIO extenders and, of course, a built-in MicroSD card reader. The audio quality is impressive too, and the project page has some MP3 files of audio recorded using this device that are worth listening to.

Whether you want the highest sound quality for your headphones while you listen to music, or you need a pocket-sized audio recording device, this might be the way to go. The project files are all available so you can build this from the ground up as well. Once you have that knocked out, you can move on to building your own speakers.

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Floating Power Plants; The Coastal City Solution Sure To Be Increasingly Popular

October 3, 2019 by 62 Comments

Building new things in an existing city is hard. Usually, new development means tearing down existing structures. Doing so for apartment complexes or new skyscrapers is one thing, but infrastructure is much more complicated, both from an engineering perspective and an economical one. Not only do people not want to foot the tax bill for things they may not see an immediate benefit from, but it can be difficult to find the space for bigger roads, more pipelines, or subway tunnels in a crowded urban area. It’s even harder for infrastructure that most consider an eyesore, like a power plant or electric substation. It’s no surprise then that some of the largest cities in the world have been making use of floating power plants rather than constructing them on dry land.

The latest city to entertain a bid for a new floating power plant (FPP) is New York, which is seeking to augment its current fleet of barge-based power stations already in operation. It already operates the largest FPP in the world at Gowanus in Brooklyn, which is able to output 640 MW of electricity. There’s also a 320 MW plant nearby as well, and the new plants would add eight 76 MW generators to New York City’s grid.

Let’s take a look at what goes into these barge-based generator designs.

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