Customizable Bird Clock Sings The Hours By

For those looking to build their own clocks, one of the easiest ways to get started is with a pre-built module that uses a simple quartz oscillator and drives a set of hands. This generally doesn’t allow for much design of the clock besides the face, and since [core weaver] was building a clock that plays bird songs, a much more hackable clock driver was needed to interface with the rest of the electronics needed to build this project.

The clock hands for this build are driven by a double stepper motor which controls an hour and minute hand coaxially but independently. Originally an H-bridge circuit was designed for driving each of the hands but they draw so little current in this configuration that they could be driven by the microcontroller directly. A DS3231 clock is used for timekeeping connected to an ATMega128a which controls everything else. At the start of each hour the clock plays a corresponding bird song by communicating with an mp3 module, and a remote control can also be used to play the songs on demand.

Bird clocks are not an uncommon thing to find off the shelf, but this one adds a number of customizations that let it fly above those offerings, including customizing the sounds that play on the hour and adding remote control capabilities, a lithium battery charging circuit, and a number of other creature comforts. If you’re looking for even more unique bird clock designs this binary bird clock might fit the bill.

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Is The Frequency Domain A Real Place?

When analyzing data, one can use a variety of transformations on the data to massage it into a form that works better to tease out the information one is interested in. One such example is the application of the Fourier transform, which transforms a data set from the time domain into the frequency domain. Yet what is this frequency domain really? After enticing us to follow the white rabbit down a sudden plummet into the intangible question of what is and what is not, [lcamtuf] shows us around aspects of the frequency domain and kin.

One thing about the (discrete) Fourier transform is that it is excellent at analyzing data that consists out of sinewaves, such as audio signals. Yet when using the Fourier transform for square waves, the resulting output is less than useful, almost as if square waves are not real. Similarly, other transforms exist which work great for square waves, but turn everything else into meaningless harmonics. Starting with the discrete cosine transform (DCT), this gets us into Walsh and Hadamard matrices and the Walsh-Hadamard Transform (WHT), and their usage with transforming data from the time into the frequency domain.

Ultimately it would seem that the frequency domain is as real as it needs to be, albeit that its appearance is wholly dependent on the algorithm used to create it, whether this the DFT, DCT, WHT or something else entirely.

MIDI Spoon Piano Is Exactly What You Think It Is

Pianos traditionally had keys made out of ivory, but there’s a great way to avoid that if you want to save the elephants. You can build a keyboard using spoons, as demonstrated by [JCo Audio]. 

The build relies on twelve metal spoons to act as the keys of the instrument. They’re assembled into a wooden base in a manner roughly approximating the white and black keys of a conventional piano keyboard, using 3D-printed inserts to hold them in place. They’re hooked up to a Raspberry Pi Pico via a Pico Touch 2 board, which allows the spoons to be used as capacitive touch pads. Code from [todbot] was then used to take input from the 12 spoons and turn it into MIDI data. From there, hooking the Pi Pico up to a PC running some kind of MIDI synth is enough to make sounds.

It’s a simple build, but a functional one. Plus, it lets you ask your friends if they’d like to hear you play the spoons. The key here is to make a big show of hooking your instrument up to a laptop while explaining you’re not going to play the spoons a la the folk instrument, but you’re going to play a synth instead. Then you should use the spoon keyboard to play emulated spoon samples anyway. It’s called doubling down. Video after the break.

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Big Server Fan Becomes Fume Extractor

[Anthony Kouttron] wanted a fume extractor for his personal electronics lab, but he didn’t like the look of the cheap off-the-shelf units that he found. Ultimately, he figured it couldn’t be that hard to build own portable fume extractor instead.

The build is based around a mighty 110-watt centrifugal fan from an IBM server that’s rated at approximately 500 CFM. It’s a hefty unit, and it should be, given that it retails at over $200 on DigiKey. [Anthony] paired this fan with off-the-shelf HEPA and activated carbon filters. These are readily available from a variety of retailers. He didn’t want to DIY that part of the build, as the filter selection is critical to ensuring the unit actually captures the bad stuff in the air. He ended up building a custom power supply for the 12-volt fan, allowing it to run from common drill batteries for practicality’s sake.

Few of us have need for such a beefy fume extractor on the regular. Indeed, many hobbyists choose to ignore the risk from soldering or 3D printing fumes. Still, for those that want a beefy fume extractor they can build themselves, it might be worth looking over [Anthony]’s initial work.

We’ve seen some other great DIY fume extractors before, too. Even those that use drill batteries! If you’ve been cooking up your own solution, don’t hesitate to drop us a line!

Pump It Up Gets Homebrew GBA Port That Rocks

Pump It Up is a popular music video game that hails from South Korea. It’s similar in vibe to Dance Dance Revolution and In The Groove, but it has an extra arrow panel to make life harder. [Rodrigo Alfonso] loved it so much, he ported it to the Game Boy Advance.

The port looks fantastic, with all the fast-moving arrows and lovely sprite-based graphics you could dream of. But more than that, [Rodrigo’s] port is very fully featured. It doesn’t rely on tracked or sampled music, instead using actual GSM audio files for the songs.

It can also accept input from a PS/2 keyboard, and you can even do multiplayer over the GBA’s Wireless Adapter. What’s even cooler is that some of the game’s neat features have been broken out into separate libraries so other developers can use them. If you need a Serial Port library for the GBA, or a way to read the SD card on flash carts, [Rodrigo] has put the code on GitHub.

As you might have guessed, this isn’t the first time [Rodrigo] has pushed the limits on what Nintendo’s 32-bit handheld can do.

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DisplayPort: Hacking And Examples

So far, I’ve talked about why DisplayPort is the future, introduced the basics of how to work with it on the hacker level, took apart and tamed the DisplayPort altmode, and recently, went through the eDP (embedded DisplayPort) display technology. This time, I want to give you a project library to reference, so that your hacking goes as smoothly as possible – real-world examples of open-source DisplayPort boards, a few boards I’ve worked on, part numbers, and whatever other information you might need.

Even this wonderful build is not immune from wasting power on unnecessary video conversion

Over the past few years, I’ve noticed that a non-zero amount of cyberdeck builders buy eDP screens with HDMI converter boards on Aliexpress, then connect them to SBCs using USB-C to HDMI adapters, or ignore the onboard eDP port; even this super cool Framework-based cyberdeck has done that! I get that it’s the simplest option, but I do believe that you ought to know how to improve it. The issue is that this double-conversion decreases the battery life significantly by burning two extra ASICs doing video conversion back and forth. Every hour of battery life matters in a cyberdeck, doubly so if it’s based on a low-power device already – you could easily cut your battery life in half if you’re not careful!

With these projects and references in your arsenal, my aim is that DisplayPort becomes way more comfortable for you to work with. Thankfully, there are quite a few projects to reference by now – let’s delve in.

Right out of the gate – are you looking for an SBC with DisplayPort support? The BoardDB website, a database of single-board computers, has a DisplayPort filter – click this link with the filter already enabled and browse through.

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A 3D-printed clock that uses flaps for the digits that get rotated.

Non-Split-Flap Clock Does It With Fewer Flaps

As cool as split-flap clocks and displays are, they do have a few disadvantages. The mechanism sticks out on the side, and the whole thing relies on gravity. Some people don’t care for the visual split in the middle of each digit that comes as a result. And their cousins, the Numechron clocks? Those wheels, especially the hours wheel, are really big compared to the size of what they display, so the clock housings are huge by comparison.

[shiura] decided to re-invent the digital display and came up with this extremely cool spinning flap mechanism that uses a lip to flip each flap after it is shown. Thanks to this design, only half the number of flaps are needed. Not only is the face of the clock able to be much larger compared to the overall size of the thing, the whole unit is quite shallow. Plus, [shiura] tilted the display 15° for better visibility.

If you want to build one of these for yourself, [shiura] has all the STLs available and some pretty great instructions. Besides the printed parts, you don’t need much more than the microcontroller of your choice and a stepper motor. Check out the demo/build video after the break, and stick around for the assembly video.

Don’t mind the visual split in the numbers? Check out this split-flap clock that uses a bunch of magnets.

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