A Steam Engine For Empty Beer Cans

October 27, 2022 by Al Williams 10 Comments

If Hero — the ancient Greek inventor — had been able to enjoy a beer after work, he might have pulled a trick like [BevCanTech] did: use it to create a simple steam engine. Of course, we aren’t sure why it has to be a beer can, but even with a soda can there is a fundamental problem: the can is open, assuming you’ve already enjoyed the beverage.

A pressure vessel with a big gaping hole in it isn’t much of a pressure vessel. The resealing process was actually quite simple. First, you bend back the tab to close up the opening as best you can. Next, you use cyanoacrylate glue and baking soda to seal up what’s left. We wondered if you could use epoxy, hot glue, or UV-curable resin. The top might get too hot for hot glue to last, but we aren’t sure.

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A Collection Of Websites That Look Like Desktops

October 27, 2022 by Lewin Day 15 Comments

Web design has come a long way since those halcyon days of Web 1.0. There are plenty of rules about how to make a clean and efficient website, but sometimes it’s more fun to throw them out and just be creative instead. In that vein, [Simone] has curated a wonderful collection of websites that emulate the computer desktop experience online.

The collection’s website very much fits this theme. Upon visiting, an Award BIOS screen flashes up. From there, we get a Windows 95-like interface full of links to other sites that emulate a computer desktop layout. There’s even a 3D screensaver that pops up if you mouse away for too long.

There’s Browso.app, which semi-accurately tells you information about your computer in a theme reminiscent of MacOS 9. Meanwhile, clicking on “It Is As if You Were Doing Work” will take you to a weird game that’s compelling in its replication of office banality. Nightwave Plaza offers exquisite vaporwave vibes, while others simply intend to faithfully recreate various OSes in a browser window.

It’s a fun collection of websites that go from the weirdly afamiliar to downright impressive recreations of former realities. It’s certainly fun to click around for a while and see what’s out there. We do love some good web ephemera around these parts!

Computing Fluidly

October 27, 2022 by Al Williams 20 Comments

Computers come in many forms, depending on your definition. We’ve seen computers and computer gates built out of things as diverse as marbles, relays, and — of course — transistors. However, there are logic gate systems that use a property of moving fluids to form logic gates and a bistable element. That’s all the pieces you need to build a working computer.

It may sound far-fetched, but there have been general-purpose computers built using this technology. It is also used in specialized applications where fluids are already flowing, like shower heads, automotive transmissions, and in places where electronics are prone to misbehave. Many think the field will see a resurgence when we need to build logic at the molecular level for nanotech applications, too.

Basics

In its most basic form, a fluidic gate uses flow as a logic 1 and less flow to be a logic 0. Merging two streams together provides an OR gate. Using a supply stream that you can divert with a control stream provides a NOT function. Given enough inverters and OR gates, you can build everything else.

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A diagram showing an LED on the left, a lever-style plumbing valve in the center, and an Arduino Uno on the right.

Plumbing Valves As Heavy Duty Analog Inputs

October 24, 2022 by Navarre Bartz 36 Comments

Input devices that can handle rough and tumble environments aren’t nearly as varied as their more fragile siblings. [Alastair Aitchison] has devised a brilliant way of detecting inputs from plumbing valves that opens up another option. (YouTube) [via Arduino Blog]

While [Aitchison] could’ve run the plumbing valves with water inside and detected flow, he decided the more elegant solution would be to use photosensors and an LED to simplify the system. This avoids the added cost of a pump and flow sensors as well as the questionable proposition of mixing electronics and water. By analyzing the change in light intensity as the valve closes or opens, you can take input for a range of values or set a threshold for an on/off condition.

[Aitchison] designed these for an escape room, but we can see them being great for museums, amusement parks, or even for (train) simulators. He says one of the main reasons he picked plumbing valves was for their aesthetics. Industrial switches and arcade buttons have their place, but certainly aren’t the best fit in some situations, especially if you’re going for a period feel. Plus, since the sensor itself doesn’t have any moving parts, these analog inputs will be easy to repair should anything happen to the valve itself.

If you’re looking for more unusual inputs, check out the winners of our Odd Inputs and Peculiar Peripherals contest or this typewriter that runs Linux.

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Trying To Build The World’s Fastest Roomba

October 22, 2022 by Lewin Day 7 Comments

A lot of people complain that Roombas are unreliable, poor at their job, or just plain annoying. Few people complain they’re not fast enough in a straight line. Regardless, [electrosync] set about building the world’s fastest Roomba for his own personal satisfaction.

For this challenge, [electrosync] set his own rules. The build must look like a Roomba, use two drive wheels, and one motor per wheel. It also has to maintain its vacuum functionality. After stripping down a used Roomba, he set about carving out space in the chassis for upgraded hardware. Brushed DC 775 motors were selected for the drivetrain, and these run through a 3:1 planetary reduction gearbox. 3D-printed mounts were then used to install the new motors in the existing chassis. New 3D-printed wheels completed the drivetrain. The original Ni-MH cells were replaced with a pair of 3-cell lithium polymer batteries for more power.

Measured with a Bluetooth GPS device, the upgraded Roomba achieved an impressive 36 km/h (22 MPH). With new wheel designs clad in urethane rubber and an improved anti-wheelie device, it hit a mighty 49 km/h (30 MPH). Adding 4-cell batteries pushed things further to 57 km/h (35 MPH), but the Roomba became difficult to control.

The gauntlet has been thrown down. Do you think you can build a faster Roomba? Time to get hacking! Video after the break.

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Forearm Muscle Contraction Sensor Is Useful Component For Open Source Prosthetics

October 20, 2022 by Lewin Day 2 Comments

Being able to actuate parts of a prosthetic limb can make it much more useful. To help in this goal for partial arm or hand amputees, [TURFPTAx] has developed a sensor for detecting forearm muscle contractions.

The sensor itself is cost-effective and simple to build.

The build is part of the Open Prosthetics project, which aims to offer open designs for various types of prosthetic devices. It apes common commercial designs using a simple electromechanical system.

The build relies on magnets mounted on twelve pistons that move when the muscles contract under the skin. The pistons are sprung to allow them to follow the expansion and contractions of the muscles, and the motion of the magnets is detected by hall effect sensors. The system is bulkier than some other solutions, but has the benefit of clean output and the ability to detect the movement of several distinct muscle groups. The data is all collected by an ESP32 which is then sent wirelessly to a computer for measurement, with [TURFPTAx] using the PyGame library to plot the sensor data.

[TURFPTAx] notes that the output of the sensors would be perfect to input into a machine learning system. Video after the break.

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UV Monitoring Budgie Keeps An Eye On Exposure Levels

October 19, 2022 by Lewin Day 2 Comments

UV rays are great at helping us generate vitamin D, but they can also be harmful, causing sunburn and even melanoma. To help kids keep track of the UV index in his local area, [Jude Pullen] created the UV Budgie.

The build is based around an Arduino Nano 33 IoT board, which queries the Met Office’s API to determine the UV level in the area. The relevant data is then displayed on a small e-ink display, with cute little sun characters telling you about the prevailing conditions. It also announces the current risk level with recorded voice samples, advising on whether precautions should be taken, such as using sunscreen or sheltering inside for the worst days. Plus, there’s a bird that flaps its wings to announce an update, actuated by a small servo in the base.

It’s a fun build that should help [Jude] and his family remain sun safe in the summer. [Jude] notes the build could also be reprogrammed to share other warnings, too. APIs to query local air quality or radiation levels are just some of the ideas that come to mind. Video after the break.

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