ArduinoMania

In a curious historical twist, the “Twelve days of Christmas” are actually the days of revelry that followed the 25th. The preceding period, Advent, was traditionally a fast, not unlike Lent. When and why a fast became an excuse for chocolate calendars we cannot say, but this historical information is presented to explain that this great hack by [Kevin], making a vintage speech synthesizer chip sing the classic carol will remain relevant at least until January 5th — or perhaps even the 19th, for the Orthodox amongst us.

The chip in question is an SP0256A-AL2, which you may remember from various speech projects for 8-bit computers back in the day. It can talk, after a fashion, by reproducing 56 “allophones” — the sounds that make up English speech — from ROM. Singing, though? We cannot recall much of that back in the day, but then, a talking computer was impressive enough.

As it turns out this is building on an earlier hack [Kevin] did in which he used an Arduino to make the venerable speech chip MIDI controllable. In that project’s write-up it is revealed that a Si5351 programmable clock module is used to give a variable pitch signal to the speech synthesizer. In this way he’s able to get about an octave an a half, which is good enough when the carol in question only spans one octave.

Of course the pitch signal needs to be varied by something and for that the venerable Arduino once again takes the place of an 8-bit computer. In this case it’s pre-programmed, but can also be set up for MIDI control.Of course nothing says you can’t use true retro hardware or a more-capable RP2040 instead of the Amtel chip.

It’s sad to think how much compute power has been wasted this year on AI-generated novelty carols when a little bit of 1980s silicon and some ingenuity can do nearly as good — or better, depending on your tastes.

[Rick] had a problem. His garage refrigerator was tasked with a critical duty—keeping refreshing beverages at low temperature. Unfortunately, it had failed—the condenser was forever running, or not running at all. The beverages were either frozen, or lukewarm, regardless of the thermostat setting. There was nothing for it—the controller had to be rebuilt from scratch.

Thankfully, [Rick]’s junk drawer was obliging. He was able to find an Arduino Uno R4, complete with WiFi connectivity courtesy of the ESP32 microcontroller onboard. This was paired with a DHT11 sensor, which provided temperature and humidity measurements. [Rick] began testing the hardware by spitting out temperature readings on the Uno’s LED matrix.

Once that was working, the microcontroller had to be given control over the fridge itself. This was achieved by programming it to activate a Kasa brand smart plug, which could switch mains power to the fridge as needed. The Uno simply emulated the action of the Kasa phone app to switch the smart plug on and off to control the fridge’s temperature, with the fridge essentially running flat out whenever it was switched on. The Uno also logs temperature to a server so [Rick] can make sure temperatures remain in the proper range.

We’ve seen some great beverage-cooling hacks over the years. If you’ve mastered your own hacky methods of keeping the colas chilled, don’t hesitate to let us know on the tipsline.

Want to know if somebody is lying? It’s always so hard to tell. [dbmaking] has whipped up a fun little polygraph, otherwise known as a lie detector. It’s nowhere near as complex as the ones you’ve seen on TV, but it might be just as good when it comes to finding the truth.

The project keeps things simple by focusing on two major biometric readouts — heart rate and skin conductivity. When it comes to the beating heart, [dbmaking] went hardcore and chose an AD8232 ECG device, rather than relying on the crutch that is pulse oximetry. It picks up heart signals via three leads that are just like those they stick on you in the emergency room. Skin conductivity is measured with a pair of electrodes that attach to the fingers with Velcro straps. The readings from these inputs are measured and then used to determine truth or a lie if their values cross a certain threshold. Presumably, if you’re sweating a lot and your heart is beating like crazy, you’re telling a lie. After all, we know Olympic sprinters never tell the truth immediately after a run.

Does this work as an actual, viable lie detector? No, not really. But that’s not just because this device isn’t sophisticated enough; commercial polygraph systems have been widely discredited anyway. There simply isn’t an easy way to correlate sweating to lying, as much as TV has told us the opposite. Consider it a fun toy or prop to play with, and a great way to learn about working with microcontrollers and biometric sensors.

If you’ve got an old black and white TV, it’s probably not useful for much. There are precious few analog broadcasters left in the world and black and white isn’t that fun to watch, anyway. However, with a little work, you could repurpose that old tube as a clock, as [mircemk] demonstrates.

The build is based around an Arduino Nano R3. This isn’t a particularly powerful microcontroller board, but it’s good enough to run the classic TVOut library. This library lets you generate composite video on an Atmel AVR microcontroller with an absolute minimum of supporting circuitry. [mircemk] paired the Arduino with a DS3231 real-time clock, and whipped up code to display the time and date on the composite video output. He then also demonstrates how to hack the signal into an old TV that doesn’t have a specific input for composite signals.

You’ll note the headline says “any old TV can be a clock,” and that’s for good reason. Newer TVs tend to eschew the classic composite video input, so the TVOut library won’t be any good if you’re trying to get a display up on your modern-era flatscreen. In any case, we’ve seen the TVOut library put to good use before, too. Video after the break.

Pinball machines have something for everyone. They’re engaging, fast-paced games available in a variety of sizes and difficulties, and legend has it that they can be played even while deaf and blind. Wizardry aside, pinball machines have a lot to offer those of us around here as well, as they’re a complex mix of analog and digital components, games, computers, and artistry. [Daniele Tartaglia] is showing off every one of his skills to build a tabletop pinball machine completely from the ground up.

This is the latest in a series of videos documenting [Daniele]’s project, so he already has the general arrangement of the game set up. He has some improved ball-counting devices to enhance the game’s ability to keep track of ball position. [Daniele] also builds a few chutes and chimneys for the ball to pass outside of the play field. Next up are flippers and some of the bumpers.  The video is rounded out with conductive targets built completely from scratch using metal zip ties. With a machine as complex as this, there are many points during the build where he has to stop and redesign parts. Prototyping as he goes, [Daniele] adds to the distinctive flair of this unique game.

This build truly puts every tool in [Daniele]’s toolbox to work, from a laser cutter, lathe, and 3D printer to various microcontrollers, solenoids, and electronics. He seamlessly blends the analog world of steel ball bearings and rubber bumpers with the digital world of scoring, automation, lighting, and sound. Pinball machines are experiencing a bit of a resurgence, meaning many of the classic tables are expensive collector’s items. If you want to build your own, we featured a great resource for others like [Daniele] who want to build one of these intricate machines themselves.

Thanks to [Aaron] for the tip!

Halloween is about tricks and treats, but who wouldn’t fancy a bit to drink with that? [John Sutley] decided to complete his Halloween party with a drink dispenser looking as though it was dumped by a backstreet laboratory. It’s not only an impressive looking separating funnel, it even runs on an Arduino. The setup combines lab glassware, servo motors, and an industrial control panel straight from a process plant.

The power management appeared the most challenging part. The three servos drew more current than one Arduino could handle. [John] overcame voltage sag, brownouts, and ghostly resets. A healthy 1000 µF capacitor across the 5-volt rail fixed it. With a bit of PWM control and some C++, [John] managed to finish up his interactive bar system where guests could seal their own doom by pressing simple buttons.

This combines the thrill of Halloween with ‘the ghost in the machine’. Going past the question whether you should ever drink from a test tube – what color would you pick? Lingonberry juice or aqua regia, who could tell? From this video, we wouldn’t trust the bartender on it – but build it yourself and see what it brings you!

If you’re blessed with high water pressure at home, you probably love how it helps blast grime from your dishes and provides a pleasant washing experience. However, it can also cause a wonderful mess when that water splashes all over your countertops. [vgmllr] has whipped up a simple solution to this problem by installing an automatic splash guard.

The concept is simple enough—install a pair of flat guards that raise up when the sink is running, in order to stop water getting everywhere. To achieve this, [vgmllr] grabbed an Arduino, and hooked it up to a piezo element, which acts as a water sensor.

The piezo is attached to the bottom of the sink, and effectively acts as a microphone, hooked up to one of the Arduino’s analog-to-digital pins. When water flow is detected, the Arduino commands two servos to raise a pair of 3D printed arms that run up and down the outside of the sink. Each arm is fitted with magnets, which mate with another pair of magnets on the splash shields inside the sink. When the arms go up, the splash shields go up, and when the arms go down, the splash shields go down.

It’s an ingenious design, mostly because the installation is so clean and seamless. By using magnets to move the splash shields, [vgmllr] eliminated any need to drill through the sink, or deal with any pesky seals or potential water leaks. Plus, if the splash shields are getting in the way of something, they can easily be popped off without having to disassemble the entire mechanism.

It’s a tidy little build, both practical and well-engineered. It’s not as advanced as other kitchen automations we’ve seen before, but it’s elegant in its simple utility.

Generally people equate the Arduino hardware platforms with MCU-centric options that are great for things like low-powered embedded computing, but less for running desktop operating systems. This looks about to change with the Arduino Uno Q, which keeps the familiar Uno formfactor, but features both a single-core Cortex-M33 STM32U575 MCU and a quad-core Cortex-A53 Qualcomm Dragonwing QRB2210 SoC.

According to the store page the board will ship starting October 24, with the price being $44 USD. This gets you a board with the aforementioned SoC and MCU, as well as 2 GB of LPDDR4 and 16 GB of eMMC. There’s also a WiFi and Bluetooth module present, which can be used with whatever OS you decide to install on the Qualcomm SoC.

This new product comes right on the heels of Arduino being acquired by Qualcomm. Whether the Uno Q is a worthy purchase mostly depends on what you intend to use the board for, with the SoC’s I/O going via a single USB-C connector which is also used for its power supply. This means that a USB-C expansion hub is basically required if you want to have video output, additional USB connectors, etc. If you wish to run a headless OS install this would of course be much less of a concern.

What does one do with old circuit boards and projects? Throwing them out doesn’t feel right, but storage space is at a premium for most of us. [Gregory Charvat] suggests doing what he did: combining them all into a wall-mountable panel in order to memorialize them, creating a functional digital clock in the process. As a side benefit, it frees up storage space!

Memorializing and honoring his old hardware is a journey that involved more than just gluing components to a panel and hanging it on the wall. [Gregory] went through his old projects one by one, doing repairs where necessary and modifying as required to ensure that each unit could power up, and did something once it did. Composition-wise, earlier projects (some from childhood) are mounted near the bottom. The higher up on the panel, the more recent the project.

As mentioned, the whole panel is more than just a collage of vintage hardware — it functions as a digital clock, complete with seven-segment LED displays and a sheet metal panel festooned with salvaged controls. Behind it all, an Arduino MEGA takes care of running the show.

Creating it was clearly a nostalgic journey for [Gregory], resulting in a piece that celebrates and showcases his hardware work into something functional that seems to have a life of its own. You can get a closer look in the video embedded below the page break.

This really seems like a rewarding way to memorialize one’s old projects, and maybe even help let go of unfinished ones.

And of course, we’re also a fan of the way it frees up space. After all, many of us do not thrive in clutter and our own [Gerrit Coetzee] has some guidance and advice on controlling it.

As we all look across a sea of lifeless, nearly identically-styled consumer goods, a few of us have become nostalgic for a time when products like stereo equipment, phones, appliances, homes, cars, and furniture didn’t all look indistinguishable. Computers suffered a similar fate, with nearly everything designed to be flat and minimalist with very little character. To be sure there are plenty of retro computing projects to recapture nostalgia, but to get useful, modern hardware in a fun, retro-themed case check out this desktop build from [Mar] that hides a few unique extras.

The PC itself is a modern build with an up-to-date operating system, but hidden in a 386-era case with early-90s styling. The real gem of this build though is the floppy disk drive, which looks unaltered on the surface. But its core functionality has been removed and in its place an Arduino sits, looking for NFC devices. The floppy disks similarly had NFC tags installed so that when they interact with the Arduino,it can send a command to the computer to launch a corresponding game. To the user it looks as though the game loads from a floppy disk, much like it would have in the 90s albeit with much more speed and much less noise.

Modern industrial design is something that we’ve generally bemoaned as of late, and it’s great to see some of us rebelling by building unique machines like this, not to mention repurposing hardware like floppy drives for fun new uses (which [Mar] has also open-sourced on a GitHub page). It’s not the first build to toss modern hardware in a cool PC case from days of yore, either. This Hot Wheels desktop is one of our favorites.