Modern Toilet Generates Energy

December 29, 2021 by 44 Comments

Environmental Engineering [Prof Jaeweon Cho] at South Korea’s Ulsan National Institute of Science and Technology specializes in water and waste management. He has developed an energy-generating toilet called BeeVi (pronounced beevee) that recycles your waste in three ways. Liquid waste is processed in a microbial reaction tank to make a liquid fertilizer. Solid waste is pumped into an anaerobic digestion tank, which results in methane gas used to power a silicone oxide fuel cell to make electricity. The remaining solids are composted to make fertilizer. The daily waste from one person is about 500 g, which can generate about 50 L of methane.

The BeeVi toilets, located on the UNIST campus, pay students in a digital currently called Ggools, or Honey Money in English. Each deposit earns 10 Ggools, which can be used to purchase coffee, instant noodles, and other items (one Ggool is equivalent to about $3.00 value). The output from this pilot project is used to partially power the building on campus, and to fertilize gardens on the grounds. If you want to learn more, here is a video lecture by [Prof Cho] (in English).

Waste management is an area of research around the world. The Gates Foundation has been funding research into this field for ten years, and has held a number of expos over the years highlighting innovative solutions, most recently being the 2018 Reinvent the Toilet Expo in Beijing. We wrote a piece about the future of toilets last year as well.

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The Current State Of Play In Autonomous Cars

December 29, 2021 by 54 Comments

Bluster around the advent of self-driving cars has become a constant in the automotive world in recent years. Much is promised by all comers, but real-world results – and customer-ready technologies – remain scarce on the street.

Today, we’ll dive in and take a look at the current state of play. What makes a self-driving car, how close are the main players, and what can we expect to come around the corner?

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Rat playing DOOM

Rats Learn To Play DOOM In This Automated VR Arena

December 29, 2021 by 29 Comments

When we run an article with “DOOM” in the title, it’s typically another example of getting the venerable game running on some minimalist platform. This DOOM-based VR rig for rats, though, is less about hacking DOOM, and more about hacking the rats.

What started as a side project for [Viktor Tóth] has evolved into quite a complex apparatus. At the center of the rig is an omnidirectional treadmill comprised of a polystyrene ball about the size of a bowling ball. The ball is free to rotate, with sensors detecting rotation in two axes — it’s basically a big electromechanical mouse upside down. The rat rides at the top of the ball, wearing a harness to keep it from slipping off. A large curved monitor sits right in front of the rat to display the virtual environment, which is a custom DOOM map.

With the VR rig built, [Viktor] worked on automating the training. A treat dispenser provides the proper motivation, while powered drive wheels engage with the ball to nudge the rat if it gets stuck in the virtual world. [Viktor] says he has trained three rats — [Romero], [Carmack], and [Tom] — to walk down a straight hallway using this automated method. As for the meat of the game — shooting monsters — [Viktor] has that covered too, with a sensor that detects when a rat rears up on its hind legs to register a shot.

Total training time to get the rats to the point seen in the video was about six weeks, and [Viktor] reports the whole thing cost him about $2000. That’s a lot of time and money, but the results are pretty interesting. If you’re more interested in minimalist DOOM builds, we understand — check out DOOM on a lightbulb, or a thermostat, or even a GPS.

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The Three Cent Motor Controller

December 29, 2021 by 20 Comments

If you follow the world of small microcontrollers you will certainly be familiar with the usual fare of Atmel, ARM Cortex, PIC, and others. But these aren’t the smallest or cheapest devices, below them is an entire category of grain-of-dust microcontrollers with minimal capabilities and at rock bottom prices. Maybe the most well known are the Padauk series of chips, whose PIC12-like architecture can be had for literal pennies. These are the famous 3 cent microcontrollers, but despite their fame they have a bit of a reputation in our community for being difficult to work with. [Ben Lim] dispels some of those ideas, by Padauk-enabling a motor and encoder from a printer to make a three cent motor controller.

The Padauk doesn’t have on-chip peripherals such as SPI, instead its IDE provides bit-banging code to do the job. This and some PID motor controller code makes for a straightforward task on the little chip, and with the help of a probably considerably more expensive MAX14870 it can drive the motor. For the curious, the code can be found in a Git Hub repository. There may be more accomplished motor controllers to be found, but we doubt you’ll find one with a cheaper microcontroller.

Want to know what the fuss is about with the Padauk? Our colleague [Maya Posch] has you covered.

The insides of a vacuum tube computer

1950s Vacuum Tube Computer Replica Communicates Through USB

December 28, 2021 by 15 Comments

When we talk about a “computer” today, we generally picture an electronic machine that can perform various kinds of mathematical operations, manage its program flow, move data from one place to another, and string all these functions together to perform some useful task. But once upon a time there were machines that could perform only a subset of these functions; these might be classified somewhere between computers and calculators.

One such machine was the Elektronensaldierer ES 24, built in 1955 by German computer pioneer Heinz Nixdorf. Its name translates as “electronic balancer”, with “balance” in the accounting sense meaning the difference of assets and liabilities. Designed to interface with a punch card machine from French manufacturer Bull, it contained several hundred vacuum tubes and could be used to add and subtract numbers stored on those punch cards.

[Henry Westphal] decided to make a modern copy of the ES 24 (translated), based on Nixdorf’s original schematics, for display in the HNF computer museum in Paderborn. The result is a huge display containing 204 tubes as well as a massive power supply. Like the 1955 original it can add incoming numbers and output the result as a twelve-digit decimal number. To make its inner workings visible, [Henry] also added a status light to each tube, showing whether it is storing a “0” or a “1”. This makes for a beautiful Blinkenlights display that shows the bits moving through the machine’s inner circuits.

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UV Printing PCBs

December 28, 2021 by 12 Comments

We always enjoy [Thomas Sanladerer’s] 3D printing videos. But his latest isn’t only about 3D printing. He shows how he uses a DLP printer — which has UV light, after all — to expose PC board blanks with great results. Honestly, once we heard the idea, we immediately saw how that could work it is surprising more people aren’t taking advantage of their DLP printers like that. Of course, [Thomas] does his usual thorough treatment of the topic.

Really, this isn’t exactly 3D printing even though it uses a 3D printer. Exposing boards with UV light and artwork is an old process that has been around for years, usually using transparency film and a UV light source. With a printer, you can create artwork digitally and the UV light source is already there.

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A 1981 Centaur pinball table rebuilt into a coffee table.

Clear Off The Coffee Table, It’s Pinball Time

December 28, 2021 by 10 Comments

Like many of us, [BuildXYZ] has always wanted to own a pinball machine, but doesn’t have the space to justify buying such a big and heavy toy. But where there’s a will, there’s a way. [BuildXYZ] figured that if they could build a pinball machine into a coffee table form factor, they’d be at least halfway to justification.

[BuildXYZ] didn’t choose just any pin. After doing a bunch of research, they settled on 1981’s Bally Centaur because it’s an early solid-state machine, and it’s one of the best. It has no secondary playfield levels to deal with, making it much easier to do this project.

Where do we even start to describe this beautiful labor of love? There are too many details to list, but know that it seems to be equal amounts of restoration work and custom work that brought this table together. The build video after the break is definitely worth your time, and you’ll gain a much better appreciation of the amount of time that went into this, from the custom score decoder chip built on an FPGA to the 3D printed replacement drop targets and new acrylic bits to replace the yellowing ones from the playfield.

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