Arduino Uno

122 Articles

Amiga? Arduino? AMeagerBall Gets The Uno Bouncing

November 19, 2025 by 9 Comments

When the iconic “Boing Ball” first debuted 40 years ago, it was a wonder to behold. There was nothing like it in the home compuing world upto that time, and it showed that Commodore’s new “Amiga” was a powerhouse sure to last the test of time. Forty years later, the Amiga as we knew it then might not be with us anymore, but [Mark Wilson] is recreating its iconic demo on a microcontroller– but not just any microcontroller. “AMeagerBall” is an Arduino Uno exclusive, and it even tells the time.

Like the original “Boing Ball”, the demo is running at 320×240, though on a touch LCD shield instead of a CRT. Unlike some microcontrollers, the Uno doesn’t have the horsepower to just brute-force emulate a 1980s home computer, so [Mark] has had to recreate the boing ball from scratch. He’s not doing it with any graphics libraries, either. On the Uno that would be too slow, so [Mark] is driving the LCD directly to its appropriate registers, to stay close enough to the metal to make it work. That means if you’re going to try the code on his GitHub repository, you’ll need to be sure to use matching hardware or be prepared to port it.

One of the things about Amiga’s demo that was so impressive is that it hardly made use of the CPU, allowing the Workbench to be pulled up while the ball bounced. That’s not the case here, as the UNO doesn’t have any extra graphics chips. Still, [Mark] was able to squeeze enough horsepower out of everyone’s favourite ATmega to present us with an Amiga-styled clock– either analog, digital, or in the workbench title bar in that iconic blue-and-white. To keep the clock accurate, he’s squeezed an RTC module in, too. Lovely! The different clocks can be accessed via the touchscreen.

Oh, did we forget to mention that the touchscreen is implemented? This certainly stretches the hardware far enough to be considered a demo. If just a bouncing ball doesn’t work the UNO hard enough for you, try booting Linux.

This isn’t the first bouncing ball demo we’ve seen on a microcontroller:  here are four of them bouncing in an ATtiny85.

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Theremin-Style MIDI Controller Does It With Lasers

September 7, 2025 by 7 Comments

Strictly speaking, a Theremin uses a pair of antennae that act as capacitors in a specific R/C circuit. Looking at [aritrakdebnath2003]’s MIDI THEREMIN, we see it works differently, but it does play in the manner of the exotic radio instrument, so we suppose it can use the name.

The MIDI THEREMIN is purely a MIDI controller. It sends note data to a computer or synthesizer, and from there, you can get whatever sound at whatever volume you desire. The device’s brain is an Arduino Uno, and MIDI-out for the Arduino has been a solved problem for a long while now.

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2025 One Hertz Challenge: Digital Clock Built With Analog Timer

August 13, 2025 by 1 Comment

You can use a microcontroller to build a clock. After all, a clock is just something that counts the passage of time. The only problem is that microcontrollers can’t track time very accurately. They need some kind of external timing source that doesn’t drift as much as the microcontroller’s primary clock oscillator. To that end, [Josh] wanted to try using a rather famous IC with his Arduino to build a viable timepiece.

[Josh]’s idea was straightforward—employ a 555 timer IC to generate a square wave at 1 Hz. He set up an Arduino Uno to count the pulses using edge detection. This allowed for a reliable count which would serve as the timebase for a simple 24-hour clock. The time was then displayed on an OLED display attached over I2C, while raw pulses from the 555 were counted on a 7-segment display as a useful debugging measure. Setting the time is easy, with a few pushbuttons hooked up to the Arduino for this purpose.

[Josh] claims a drift of “only ~0.5 seconds” but does not state over what time period this drift occurs. In any case, 555s are not really used for timekeeping purposes in this way, because timers based on resistor-capacitor circuits tend to drift a lot and are highly susceptible to temperature changes. However, [Josh] could easily turn this into a highly accurate clock merely by replacing the 555 square wave input with a 1PPS clock source from another type of timer or GPS device.

We’ve had quite a few clocks entered into the One Hertz Competition already, including this hilariously easy Nixie clock build. You’ve got until August 19 to get your own entry in, so wow us with your project that does something once a second!

2025 Hackaday One Hertz Challenge

Building A 3D-Printed Strandbeest

January 16, 2025 by 16 Comments

The Strandbeest is a walking machine, a creation of the celebrated artist Theo Jansen. They can look intimidating in their complexity, but it’s quite possible to build your own. In fact, if you’ve got a 3D-printer, it can be remarkably straightforward, as [Maker 101] demonstrates.

The build relies on an Arduino Uno as the brains. It’s equipped with an L293D motor driver shield to run two DC gear motors which drive the walking assemblies. Power is courtesy of a 3-cell lithium-polymer battery. The chassis, legs, and joints are all 3D-printed, and rather attractively in complimentary colors, we might add.

Controlling this little Strandbeest is simple. [Maker 101] gave the Arduino an infrared sensor which can pick up signals from a simple IR remote control. It can be driven backwards and forwards or turned left and right. What’s more, it looks particularly elegant as it walks—a hallmark of a good Strandbeest design.

Design files are available online for the curious. We love a good Strandbeest build, and some can even be useful, too! Video after the break.
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Nottingham Railway departure board in Hackspace

All Aboard The Hack Train: Nottingham’s LED Revival

January 4, 2025 by 4 Comments

Hackerspaces are no strangers to repurposing outdated tech, and Nottingham Hackspace happens to own one of those oddities one rarely gets their hands on: a railway departure board. Left idle for over a decade, it was brought back to life by [asjackson]. Originally salvaged around 2012, it remained unused until mid-2024, when [asjackson] decided to reverse-engineer it. The board now cycles between displaying Discord messages and actual train departures from Nottingham Railway Station every few minutes. The full build story can be found in this blog post.

The technical nitty-gritty is fascinating. Each side of the board contains 4,480 LEDs driven as two parallel chains. [asjackson] dove into its guts, decoding circuits, fixing misaligned logic levels, and designing custom circuit boards in KiCAD. The latest version swaps WiFi for a WizNet W5500 ethernet module and even integrates the Arduino Uno R4 directly into the board’s design. Beyond cool tech, the display connects to MQTT, pulling real-time train data and Discord messages via scripts that bridge APIs and custom Arduino code.

This board is a true gem for any hackerspace, even more so now it’s working. It waited for the exact mix of ingredients why hackerspaces exist in the first place: curiosity, persistence, and problem-solving. Nottingham Hackspace is home to a lot more, as we once wrote in this introductory article.If you don’t have room for the real thing, maybe set your sights a bit smaller.

Do you have a statement piece this cool in your hackerspace or your home? Tip us!

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Puzzle Bobble on a screen with a physical gadget in front

Crafting A Cardboard Tribute To Puzzle Bobble

January 2, 2025 by 2 Comments

What do you get when you cross cardboard, deodorant rollers, and a love for retro gaming? A marvel of DIY engineering that brings the arcade classic Puzzle Bobble to life—once again! Do you remember the original Puzzle Bobble aiming mechanism we featured 12 years ago? Now, creator [TomTilly] has returned with a revamped version, blending ingenuity with a touch of nostalgia. [Tom] truly is a Puzzle Bobble enthusiast. And who could argue that? The game’s simplicty makes for innocent yet addictive gameplay.

[Tom]’s new setup recreates Puzzle Bobble’s signature aiming mechanic using surprising materials: deodorant roller balls filled with hot glue (to diffuse LED colours), bamboo skewers, and rubber bands. At its heart is an Arduino UNO, which syncs the RGB LED ‘bubbles’ and a servo-driven aiming arm to the game’s real-time data. A Lua script monitors MAME’s memory locations to match the bubble colours and aimer position.

But this isn’t just a static display. [Tom] hints at a version 2.0: a fully functional controller complete with a handle. Imagine steering this tactile masterpiece through Puzzle Bobble’s frantic levels!

Need more inspiration? Check out other quirky hacks like [Tom]’s deodorant roller controller we featured in 2023. Whether you’re into cardboard mechanics or retro gaming, there’s no end to what clever hands can create.

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A Parts Bin MIDI Controller In 24 Hours

October 20, 2024 by 9 Comments

Part of the reason MIDI has hung on as a standard in the musical world for so long is that it is incredibly versatile. Sure, standard instruments like pianos and drums can be interfaced with a computer fairly easily using this standard, but essentially anything can be converted to a MIDI instrument with the right wiring and a little bit of coding. [Jeremy] needed to build a MIDI controller in a single day, and with just a few off-the-shelf parts he was able to piece together a musical instrument from his parts bin.

The build is housed in an off-brand protective case from a favorite American discount tool store, but the more unique part of the project is the choice to use arcade buttons as the instrument’s inputs. [Jeremy] tied eight of these buttons to an Arduino Uno to provide a full octave’s worth of notes, and before you jump to the comments to explain that there are 12 notes in an octave, he also added a button to the side of the case to bend any note when pressed simultaneously. An emergency stop button serves as a master on/off switch and a MIDI dongle on the other side serves as the interface point to a computer.

After a slight bit of debugging, the interface is up and running within [Jeremy]’s required 24-hour window. He’s eventually planning to use it to control a custom MIDI-enabled drum kit, but for now it was fun to play around with it in some other ways. He’s also posted the project code on a GitHub page. And, if this looks a bit familiar, this was not [Jeremy]’s first MIDI project. He was also the creator of one of the smallest MIDI interfaces we’ve ever seen.

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