Year: 2020

Tic Tac Arduintoe Moves The Game To 4×4

May 26, 2020 by 5 Comments

We know you’re out there spending a lot more time with your loved ones, and appreciate that you may be running out of ways to keep everyone entertained. [Mukesh] dropped us a tip because he has the antidote to boredom — a new twist on that old chestnut, Tic Tac Toe.

Instead of the usual 3×3 configuration, [Mukesh] made the grid 4×4 so the game would be more engaging. Game play is otherwise the same — this Tic Tac Toe still results in a lot of draws, but they take longer and you can’t see them coming a mile away. What’s even more engaging is that you get to push clicky buttons that light up, and don’t have to draw a grid before every game.

Under the hood is an Arduino Uno that controls 16 push buttons and their corresponding RGB LEDs. Whoever goes first is blue, and player two gets pink. If you win, your color floods the board for a brief victory animation. If the game is a tie, the board turns red. We really like the printed two-piece buttons that house the LEDs and actuate the push buttons while keeping the two separate. Toe your way past the break to check out the build video.

Intrigued by the 4×4 version, but need a build that takes more time? Try building your TTT in TTL.

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Beautiful Sourdough Bread At Home Thanks To Dynamic Recipe Parameterization

May 26, 2020 by 21 Comments

More people are making sourdough at home than ever before, and while it may not take a lot of effort to find a decent recipe, it’s quite another thing to try using recipes to figure out how and why bread actually works. Thankfully, [Makefast Workshop] has turned copious research and hundreds of trials into a dynamic sourdough (and semi-sourdough) bread recipe chock-full of of drop-down options to customize not just ingredients, but baking methods and other recipe elements as well. Want to adjust quantities or loaf styles? Play with hydration or flour type? It’s all right there, and they even have quick-set options for their personal favorites.

In order to do all this, [Makefast Workshop] needed to understand bread at a deeper level than is usually called for. During research, they observed that the format of recipes was often an obstacle to understanding how good bread actually gets made. The reason for this is simple: recipes are presented as standalone documents describing a fixed process; a set of specific steps that, when followed, yield a particular result. What they do not normally do is describe the interplay and balance between ingredients and processes, which makes it difficult to understand how and why exactly the recipe produces what it does. Without that knowledge, it’s impossible to know what elements can be adjusted, and how. The dynamic recipe changes all that.

[Makefast Workshop] performed hundreds of tests, dialing in parameters one by one, to gain the insights needed to populate their dynamic recipe. It’s got clear processes and drop-down options that dynamically update not just the recipe steps, but also the URL. This means that one can fiddle the recipe to one’s desire, then simply copy and paste the URL to keep track of what one has baked.

When it comes to thoughtful approaches to food, this certainly isn’t [Makefast Workshop]’s first rodeo. We covered their beautiful directions for creating delicious speculoos, complete with effective 3D printed molds for a modern twist on a Belgian classic.

Boot Your Pi Over USB

May 25, 2020 by 50 Comments

Historically, booting a Raspberry Pi required an SD card. However, if you follow [tynick’s] instructions, you can get a Pi 4 to boot from the USB port. Combine it with a small solid state disk drive, and you’ll get great performance, according to his post.

The caveat is this depends on a beta bootloader and, of course, you’ll still have to boot from an SD card at least once to load that bootloader. If you were deploying something serious, you’d probably want to make sure the bootloader is suitable for your needs.

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This Frequency Generator Knows How To Get Down

May 25, 2020 by 19 Comments

What kind of clever things could you do with a signal that had a period of 2 hours? Or 20? Any ideas? No seriously, tell us. Because [Joseph Eoff] has come up with a way to produce incredibly low frequency signals that stretch out for hours, and we’d love to figure out what we can do with it.

To be fair, it’s not like [Joseph] has any ideas either. He thought it would be an interesting project, and figures now that he has the technology, maybe some application will come to him. They say that if you’ve got a hammer everything looks like a nail, so maybe the next project he sends our way will be a sinusoidal fish feeder.

[Joseph] says doing the software side of things with Pure Data wasn’t a problem, but getting it out of the computer proved to be tricky. It turns out that your average computer sound card isn’t equipped to handle frequencies down into the millihertz range (big surprise), so they need to be coaxed out with some extra hardware. Using a simple circuit not unlike an AM demodulator, he’s able to extract the low-frequency signal from a 16 kHz carrier.

So if you ever find yourself in need of a handful of hertz, now you’ve got the tool to generate them. At least it’s more practical than how they used to generate low frequency signals back in the 1900s.

Herb Garden Is Smarter Than The Average… Garden

May 25, 2020 by 11 Comments
After 13 days, the herbs are showing good signs of growth.

Herbs are a great way to spice up any dish. Often they don’t need much, meaning that it’s possible to grow a useful amount in a fairly compact area. [Sunyecz22] wanted to do just that, so built a convenient indoor herb garden, giving it some smarts along the way.

The project is built around an Arduino Mega, a venerable stalwart of the scene that comes in handy on projects requiring plenty of digital I/O. It’s paired with four soil moisture sensors, one per planter pot to keep an eye on water levels. The system also controls LEDs which provide light based on the time of day to help the herbs grow. Finally, a tidy 3D printed enclosure gives the project a neat, finished look.

It’s a build that’s a straightforward way to get into automatic plant maintenance, and leaves plenty of scope for future work. With the capable Arduino Mega on hand, it would be a cinch to upgrade to automatic watering down the track. We’ve seen similar builds before, too. Video after the break.

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Secret Knock Unlocks Door

May 25, 2020 by 12 Comments

Watch any movie about the years of prohibition, and you’ll probably see character gain admittance to a speakeasy by using a secret knock on the door. In the old movies, a little sliding door would open so the doorman could check you out and let you in. With [IsmailSan’s] electronic lock, the secret knock automatically unlocks the door. You can see a video of how it works, below.

(Ed Note: Grrr…GitHub repo got pulled between writing and publication. Go check out the in-links in the bottom paragraph if you’re interested in knock-detectors.)

The device uses a piezoelectric speaker to detect the knocking. A speaker is a transducer and like many transducers, it will work — to some extent — in either direction. A servo motor manages the deadbolt. An Arduino runs the whole thing.

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FPGA Raises Component Video From A Sinclair ZX Spectrum

May 25, 2020 by 39 Comments

An abiding memory of the early-80s heyday of 8-bit computing for many is operating their computer from the carpet in front of the family TV. While the kids in the computer adverts had parents who bought them a portable colour telly on which to play Jet Set Willy, the average kid had used up all the Christmas present money on the computer itself. The cable would have been an RF connection to the TV antenna socket, and the picture quality? At the time we thought it was amazing because we didn’t know any different, but with the benefit of nearly 40 years’ hindsight, it was awful.

For ZX Spectrum owners in 2020 a standard modification is to bring out a composite video signal, but [c0pperdragon] has gone a step or two beyond that with a component video interface. And this isn’t a mod in which the signals are lifted from the Spectrum’s colour encoder circuitry, instead it uses an FPGA hooked directly to the ULA chip to generate the component video itself.

The Altera chip sits on a little PCB designed to occupy the footprint of the original Astec modulator, and sports a neat bundle of wires hooked up to the various Spectrum signals it needs. There are a couple of jumpers to select the output type and resolution, it supports YPbPr or RGsB outputs and both 288p and 576p. If you think perhaps it looks a little familiar, that’s because it’s the sister project of an earlier board for the Commodore 64. So if you have a Spectrum and are annoyed by UHF and PAL, perhaps it’s worth a look.