Termi2 Is Siri Like It’s 1976

November 23, 2022 by Kristina Panos 9 Comments

What are your plans for the long weekend? If you don’t have time or don’t want to dive into a new project, why not dust off something left unfinished, or do as Hackaday alum [Cameron Coward] did recently and upgrade an old project with a new brain.

In this case, the project in question is a terminal typewriter — a Texas Instruments Silent 700 Terminal, to be exact — into a sort of late ’70’s version of Siri. The terminal typewriter is a special beast that used an acoustic coupler to send and receive both beeps and boops from distant mainframes. Whereas the first iteration of Termi used a Raspberry Pi Zero W to run a script that queries Wolfram Alpha, [Cameron] decided that between the login requirement, the boot time, and the weird formatting required to get it to work, that there had to be a better way.

Turns out that the better way is to use an ESP32 and read the “serial port”, which is a proprietary port with two serial connections — one for the acoustic coupler, and one for regular serial communication. Our favorite thing about this build, no matter the brain, is that there is a permanent record of all the questions and answers. Be sure to check out the video after the break.

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Books You Should Read: Why Buildings Fall Down

November 23, 2022 by Dan Maloney 35 Comments

People with long commutes usually come up with tricks to stay focused and alert and avoid the dangerous tendency to zone out during the drive. One trick I used to use was keeping mental track of the various construction projects I’d pass by on my way to work, noticing which piers on a new highway overpass were nearing completion, or watching steelworkers put together the complex rebar endoskeletons of a new stretch of roadway.

One project I loved to watch back in the 80s was a new high-rise going in right next to the highway, which fascinated me because of the construction method. Rather than putting together a steel frame, laying out decking, and covering each floor with concrete, the workers seemed to be fabricating each floor at ground level and then jacking them up on the vertical steel columns. I was fascinated by this because every time I passed by the floors were in a different position, spreading out vertically as the building grew.

And then one day, it just wasn’t there anymore. Where there had been columns stretching nine stories into the city sky with concrete slabs lined up ready to be jacked up into their final positions, there was just an enormous hole in the ground with a ghastly gray cloud of concrete dust rising from it. It was April 23, 1987, and what was once going to be a luxury apartment building called L’Ambience Plaza in Bridgeport, Connecticut lay pancaked into the ground, entombing the bodies of 28 construction workers.

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Hardware Store Chemicals Transform Sheets Into Waterproof Tarps

November 23, 2022 by Ryan Flowers 35 Comments

For hackers in the Northern Hemisphere, the seasons of wet and cold are upon us. Staying dry is every bit as important as staying warm, so what better than a hack or two to keep us warm and dry! All you’ll need is a bed sheet, some rope, and a run to the local hardware store, and a bit of knowledge. [NightHawkInLight] has us covered with the excellent video “Recycled Bedsheets Make The Best Waterproof Tarps” as seen below the break.

[NightHawkInLight] brings old traditional methods into the 21st century by turning away from oil, beeswax and canvas in favor of a recycled bed sheet made waterproof with silicone. The video goes into just enough detail so that you can reproduce their results without fear of working with the powerful solvent being used.

Cheap hardware store grade silicone sealant is thinned by naphtha, worked into the old bed sheet, and then hung out to dry overnight. The result? A perfectly waterproof sheet that’s just as pliable as before treatment. But how can you use it like a tarp, when there are no eyelets? If you watch the video for no other reason, check out the neat attachment trick at the end, where traditional technology is brought to the fore once again with nothing more than a rock and a slip knot.

We can imagine that the uses for such inexpensive, durable home made tarps are many. Perhaps one could put it to use when building your own Custom Cycling Camper.

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Don’t Believe Everything You Read: The Great Electric Toaster Hoax

November 23, 2022 by Al Williams 65 Comments

We’ve all looked up things on Wikipedia and, generally, it is usually correct information. However, the fact that anyone can edit it leads to abuse and makes it somewhat unreliable. Case in point? The BBC’s [Marco Silva] has the story of the great online toaster hoax which erroneously identified the inventor of the toaster with great impact.

You should read the original story, but in case you want a synopsis, here goes: Until recently, the Wikipedia entry for toasters stated that a Scottish man named Alan MacMasters invented the electric toaster in the 1800s. Sounds plausible. Even more so because several books had picked it up along with the Scottish government’s Brand Scottland website. At least one school had a day memorializing the inventor and a TV show also honored him with a special dessert named for Alan MacMasters, the supposed inventor. Continue reading “Don’t Believe Everything You Read: The Great Electric Toaster Hoax” →

The 13.5 Million Core Computer

November 23, 2022 by Al Williams 55 Comments

Having a dual- or quad-core CPU is not very exotic these days and CPUs with 12 or even 16 cores aren’t that rare. The Andromeda from Cerebras is a supercomputer with 13.5 million cores. The company claims it is one of the largest AI supercomputers ever built (but not the largest) and can perform 120 Petaflops of “dense compute.”

We aren’t sure about the methodology, but they also claim more than one exaflop of “AI computing.” The computer has a fabric backplane that can handle 96.8 terabits per second between nodes. According to a post on Extreme Tech, the core technology is a 3-plane wafer processor, WSE-2. One plane is for communications, one holds 40 GB of static RAM, and the math plane has 850,000 independent cores and 3.4 million floating point units.

The data is sent to the cores and collected by a bank of 64-core AMD EPYC 3 processors. Andromeda is optimized to handle sparse matrix computations. The company claims that the performance scales “almost linearly.” That is, as you double the number of cores used, you roughly half the total run time.

The machine is available for remote use and cost about $35 million to build. Since it uses 500 kW at peak run times, it isn’t free to operate, either. Extreme Tech notes that the Frontier computer at Oak Ridge National Labs is both larger and more precise, but it cost $600 million, so you’d expect it to be more capable.

Most homebrew “supercomputers” we see are more for learning how to work with clusters than trying to hit this sort of performance. Of course, if you have a modern graphics card, OpenCL and CUDA will let you do some of this, too, but at a much lesser scale.

The Fastest Fourier Transform In The West

November 23, 2022 by Dave Walker 22 Comments

An interesting aspect of time-varying waveforms is that by using a trick called a Fourier Transform (FT), they can be represented as the sum of their underlying frequencies. This mathematical insight is extremely helpful when processing signals digitally, and allows a simpler way to implement frequency-dependent filtration in a digital system. [klafyvel] needed this capability for a project, so started researching the best method that would fit into an Arduino Uno. In an effort to understand exactly what was going on they have significantly improved on the code size, execution time and accuracy of the previous crown-wearer.

A complete real-time Fourier Transform is a resource-heavy operation that needs more than an Arduino Uno can offer, so faster approximations have been developed over the years that exchange absolute precision for speed and size. These are known as Fast Fourier Transforms (FFTs). [klafyvel] set upon diving deep into the mathematics involved, as well as some low-level programming techniques to figure out if the trade-offs offered in the existing solutions had been optimized. The results are impressive.

Fastest FFT code benchmarking results in ms — Benchmarking results showing speed of implementation versus the competition (ApproxFFT)

Not content with producing one new award-winning algorithm, what is documented on the blog is a masterclass in really understanding a problem and there are no less than four algorithms to choose from depending on how you rank the importance of execution speed, accuracy, code size or array size.

Along the way, we are treated to some great diversions into how to approximate floats by their exponents (French text), how to control, program and gather data from an Arduino using Julia, how to massively improve the speed of the code by using trigonometric identities and how to deal with overflows when the variables get too large. There is a lot to digest in here, but the explanations are very clear and peppered with code snippets to make it easier and if you have the time to read through, you’re sure to learn a lot! The code is on GitHub here.

If you’re interested in FFTs, we’ve seen them before around these parts. Fill your boots with this link of tagged projects.

A 3D printed cat treat dispenser on a table with a laptop in the background and with a treat in it's tray and a cat on the left about to eat the treat.

Local IOT Cat Treat Dispenser

November 22, 2022 by Abe Connelly 9 Comments

[MostElectronics], like many of us, loves cats, and so wanted to make an internet connected treat dispenser for their most beloved. The result is an ingenious 3D printed mechanism connected to a Raspberry Pi that’s able to serve treats through a locally run web application.

From the software side, the Raspberry Pi uses a RESTful API that one can connect to through a static IP. The API is implemented as a Python Flask application running under a stand alone web server Python script. The web application itself keeps track of the number of treats left and provides a simple interface to dispense treats at the operators leisure. The RpiMotorLib Python library is used to control a 28BYJ-48 stepper motor through its ULN2003 controller module, which is used to rotate the inside shaft of the treat dispenser.

The mechanism to dispense treats is a stacked, compartmentalized drum, with two drum layers for food compartments that turn to drop treats. The bottom drum dispenses treats through a chute connected to the tray for the cat, leaving an empty compartment that the top drum can replenish by dropping its treats into through a staggered opening. Each compartmentalized treat drum layer provides 11 treats, allowing for a total of 22 treats with two layers stacked on top of each other. One could imagine extending the treat dispenser to include more drum layers by adding even more layers.

Source code is available on GitHub and the STL files for the dispenser are available on Thingiverse. We’ve seen cat electronic feeders before, sometimes with escalating consequences that shake us to our core and leave us questioning our superiority.

Video after the break!

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