Arduino PLC Keeps The Beat

July 6, 2024 by Bryan Cockfield 12 Comments

For most of our prototype, hobby, or one-off electronics projects it’s perfectly fine to use a development platform like an Arduino Uno or something to that effect. They’re both easy to program and easy to wire up to projects without breaking the bank. But if you step into an industrial setting where reliability is paramount even in places that are noisy, vibrating all the time, hot, or otherwise unpleasant for electronics, you’ll want to reach for a programmable logic controller (PLC) that are much more robust. There is actually a PLC from Arduino, and if you want to dip your toes into the PLC world then take a look at this drum kit based on the Arduino Opta.

With the PLC at the core of the build, it’s on to making the drumming mechanisms themselves. For that, project creator [JC Audio] is using a series of solenoids attached to camera mounts with a custom 3D printed part that allows for quick assembly and disassembly so he can get the positioning of each drum sound just right. The high hat is taken care of by the noise of an internal solenoid, with the other drums striking various real drums and other solid objects in his shops. The solenoids themselves are driven by a solid-state relay expansion module to ensure there’s enough power

While the build doesn’t sit inside a factory and run for years at a time, a musician’s stage is certainly a rough enough environment that we might reach for a PLC over a standard development board for its benefits. The code for this project is available as well at the project’s GitHub page for those looking for a more advanced timekeeper to play along with their music practice, and for more details on why you might choose a PLC for your project take a look at this Arduino vs PLC showdown from a few years ago.

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Metronome Flashes And Vibrates To The Beat

December 8, 2023 by Kristina Panos 3 Comments

Annoying though they can be, if you play any kind of instrument, you will definitely benefit from using a metronome. While many of them thock or otherwise tock, the VRRVRR metronome from [Turi] works a little differently.

In addition to flashing LEDs, the VRRVRR contains a small vibrating motor. If you’re wondering about the name, it comes from the fact that it vibrates and makes a sort of vrr vrr sound. Need to be quiet? A small switch on the side shuts off the vibrations.

The 4×4 keypad really allowed [Turi] to cram in a bunch of features using both short and long press to do different things. On short press, the digits set the tempo. When not typing in a tempo, zero can be used to enter a tempo by tapping. The letters load preset tempos, and the +/- keys increase and decrease it.

Inside the basswood enclosure is a Raspberry Pi Pico, the vibration motor, and various other bits and bobs that make it go. There’s even an LED to indicate that it’s time to charge the lithium battery. If you want to build your own, head on over to GitHub, but be sure to take the brief VRRVRR tour after the break.

We don’t see too many metronomes around here, but we do have this nice teardown to offer you.

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PendulumSynth Ties Music And Physics Together

February 17, 2022 by Lewin Day 2 Comments

Many musicians will be familiar with the metronome, a pendulum charged with generating a rhythmic tick to keep one’s performance in regular time. With PendulumSynth, [mrezanvari] takes the same basic pendulum but uses it in an altogether different musical way.

The build relies on a 10-inch plastic ball to serve as the weighted end of the pendulum, stuffed with a STM32F411CE BlackPill board, a BNO085 IMU, and an nRF radio module for sending out data for external processing. The pendulum’s motion is turned into MIDI data or CV for output to musical hardware which handles actually generating the output sounds.

The system operates in a variety of modes. Gravity mode outputs continuous MIDI data and CV relative to the continuous motion of the pendulum, while DIV3 mode tracks the pendulum’s motion and outputs 3 regular trigger points that correspond as such.

The combination of the intuitive physical nature of the pendulum and its sheer large size makes for an enticing musical exhibit. We’ve seen some other great musical installation pieces before, too. Video after the break.

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Teardown: Franz Crystal Metronome

June 22, 2021 by Tom Nardi 16 Comments

I wish I could tell you that there’s some complex decision tree at play when I select a piece of hardware to take apart for this series, but ultimately it boils down two just two factors: either the gadget was something I was personally interested in, or it was cheap. An ideal candidate would check both boxes, but that’s not always the case. This time around however, I can confidently say our subject doesn’t fall into either category.

Now don’t get me wrong, at first glance I found the Franz Crystal Metronome to be intriguing in its own way. With that vintage look, how could you not? But I’m about as far from a musician as one can get, so you’d hardly find a metronome on my wish list. As for the cost, a check on eBay seems to show there’s something of a following for these old school Franz models, with ones in good condition going for $50 to $80. Admittedly not breaking the bank, but still more than I’d like to pay for something that usually ends up as a pile of parts.

That being the case, why are you currently reading about it on Hackaday? Because it exploits something of a loophole in the selection process: it doesn’t work, and somebody gave it to me to try and figure out why. So without further ado let’s find out what literally makes a Franz Crystal Metronome tick, and see if we can’t get it doing so gain.

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Why Pendulums Sync Up, And Other Mysteries Explained

April 12, 2021 by Lewin Day 6 Comments

If you’ve ever seen fireflies flashing together at night, you’ve witnessed the glory of synchronisation. In a new video, [Veritasium] examines some of the mechanisms in nature that help create order out of chaos.

The story begins back in 1665, when [Christiaan Huygens] discovered that two pendulum clocks hanging from the same wooden beam would spontaneously synchronise over a period of time. The same principle is then demonstrated with metronomes – an experiment readily recreated in the home. Other systems that show this same eerie coordiation are then explored – from tidally locked moons orbiting around planets (like ours!), to chemical oscillators discovered by Soviet scientists during the cold war. There’s also a great explanation of the problems faced by the London Millennium Bridge, which swayed wildly under heavy foot traffic as it induced pedestrians to walk in sync.

Overall, it’s a look at some of the action behind the scenes that ties seemingly independent systems together. Learning about such things can prove useful too – it might even help you solve real world problems in your machine shop! Video after the break.

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Your Own Electronic Drum Kit

July 8, 2020 by Orlando Hoilett 6 Comments

[Jake_Of_All_Trades] wanted to take up a new drumming hobby, but he didn’t want to punish his neighbors in the process. He started considering an electric drum kit which would allow him to practice silently but still get some semblance of the real drumming experience.

Unfortunately, electric drum kits are pretty expensive compared to their acoustic counterparts, so buying an electric kit was a bit out of the question. So, like any good hacker, he decided to make his own.

He found a pretty cheap acoustic drum kit on Craigslist and decided to convert it to electric. He thought this would be a perfect opportunity to learn more about electric drum kits in general and would allow him to do as much tweaking as he wanted to in order to personalize his experience. He also figured this would be a great way to get the best of both worlds. He could get an electric kit to practice whenever he wanted without disturbing neighbors and he could easily convert back to acoustic when needed.

First, he had to do a bit of restorative work with the cheap acoustic kit he found on eBay since it was pretty worn. Then, he decided to convert the drum heads to electric using two-ply mesh drum heads made from heavy-duty fiberglass screen mesh. The fiberglass screen mesh was cheap and easy to replace in the event he needed to make repairs. He added drum and cymbal triggers with his own DIY mechanism using a piezoelectric element, similar to another hack we’ve seen. These little sensors are great for converting mechanical to electrical energy and can feed directly into a GPIO to detect when the drum or cymbal was struck. The electrical signal is then interpreted by an on-board signal processing module.

All he needed were some headphones or a small amplifier and he was good to go! Cool hack [Jake_Of_All_Trades]!

While you’re here, check out some of our best DIY musical projects over the years.

15-digit Nixie Clock Contains Mostly Non-useful Information

April 6, 2011 by Mike Szczys 15 Comments

[Jarek Lupinski] is at it again, this time building a clock using 15 Nixie tubes. Just look at the time…. wait, how do you read this now? It’s not seconds since the epoch, but an homage to a very expensive New York City art piece. [Jarek] took his inspiration from the Metronome art installation in Union Square.

We hadn’t heard of it before and were shocked to learn that this art was commissioned at $4.2 million. It belches steam and confuses passersby with its cryptic fifteen digits. It seems that the eight digits on the left mark the current time – two digits for hours, two for minutes, two for seconds, and the final digit for hundreths of a second. The seven remaining digits count down the time left in the day. So when you watch it, you see the significant digits of the display increasing, and the insignificant half decreasing.

The Nixie version rests snuggly on a 15″x4″ PCB. We’re sure it doesn’t number in the millions, but that couldn’t have been cheap to have manufactured. Each tube has its own driver chip, removing the need for multiplexing. An ATmega168 controls the clock (along with some shift registers to expand the I/O count), reading time from a DS1307 RTC chip. It looks fancy, but where’s the belching smoke on this version?