encoder

68 Articles

Lightcomposer

LightComposer – Reach Out And Touch Your Lighting

June 22, 2026 by 1 Comment

While there is a time and place for wirelessly controlled devices, sometimes you want something you can just reach out and touch to interact with, no apps to install or devices to configure. In this case [John] wanted a lamp that was just that. Drawing inspiration from the rotary phone, he created the LightComposer.

This small lamp, just a bit smaller than a hockey puck, uses a 3D printed enclosure and a straightforward PCB. It’s a very accessible project to recreate. The 3D prints are well thought out including a TPU ring on the bottom to keep the lamp from sliding around. The light source comes from 32 SK6812 LEDs, which are very similar to NeoPixels. An ATmega328P microcontroller powers the project and can easily be programmed using the Arduino IDE. A rotary encoder in the center, coupled to the top diffuser, lets you control LED brightness and color by turning it. The firmware also includes some fun hidden light-effect modes.

Head over to [John]’s site for all the files needed to make your own LightComposer, or links to buy a premade one. What devices have you made that use a straightforward physical user interface in lieu of an app? Be sure to check some of the other lamp builds we’ve featured before.

Wireless MIDI Controller Has Lots Of Knobs

January 24, 2026 by 8 Comments

We live in a golden age for MIDI controllers. [rheslip]’s contribution to the milieu is a twisty take on the format, in that it’s covered in an array of knobs. Thus the name—Twisty 2. 

The controller can be built using the Raspberry Pi Pico or Pico 2. It’s set up to read a 4×4 array of clickable encoders, plus two bonus control knobs to make 18 in total, which are read via a 74HC4067 analog mux chip. There’s also an SK6812 RGB LED for each encoder, and an OLED display for showing status information. MIDI output is via USB, or, if you purchased the W variant of the Pi Pico/Pico 2, it can operate wirelessly over Bluetooth MIDI instead. The controller is set up to send MIDI CC messages, program changes, or note on/off messages depending on its configuration. Flipping through different modes is handled with the bottom set of encoders and the OLED display.

Few musicians we’ve ever met have told us they learned how to play the encoders, and yet. The cool thing about building your own MIDI controller is you can tune it to suit whatever method of performance strikes your fancy. If the name of this build alone has you inspired, you could always whip up a MIDI controller out of a Twister mat.

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Open source mute button

Silent No More: Open-Source Fix For Mic Mishaps

August 30, 2025 by 12 Comments

“Sorry, my mic was muted…” With the rise of video calls, we’ve all found ourselves rushing to mute or unmute our mics in the midst of a call. This open-source Mute Button, sent in by [blackdevice], aims to take out the uncertainty and make toggling your mic easy.

It’s centered around a small PIC32MM microcontroller that handles the USB communications, controls the three built-in RGB LEDs, and reads the inputs from the encoder mounted to the center of this small device. The button knob combo is small enough to easily move around your desk, yet large enough to toggle without fuss when it’s your turn to talk.

To utilize all the functions of the button, you’ll need to install the Python-based driver on your machine. Doing so will let you not only toggle your microphone and volume, but it will also allow the button to light up to get your attention should you be trying to talk with the mic muted.

Although small, it’s also quite rugged, knowing it will spend its life being treated much like a game of Whac-A-Mole—slapped whenever needed. The case is designed to be 3D printed by any FDM printer, with the top knob section printed in translucent material to make the notification light clearly visible.

All of the design files, firmware, and parts list are available over on [blackdevices]’s GitHub page, and they are open-source, allowing you to tweak the design to fit your unique needs. Thank you for sending in this well-documented project, [blackdevices]; we look forward to seeing future work. If you like this type of thing, be sure to check out some of our other cool featured desk gadgets.

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Look! It’s A Knob! It’s A Jack! It’s Euroknob!

April 28, 2025 by 25 Comments

Are your Eurorack modules too crowded? Sick of your patch cables making it hard to twiddle your knobs? Then you might be very interested in the new Euroknob, the knob that sports a hidden patch cable jack.

Honestly, when we first saw the Euroknob demo board, we thought [Mitxela] had gone a little off the rails. It looks like nothing more than a PCB-mount potentiometer or perhaps an encoder with a knob attached. Twist the knob and a row of LEDs on the board light up in sequence. Nice, but not exactly what we’re used to seeing from him. But then he popped the knob off the board, revealing that what we thought was the pot body is actually a 3.5-mm audio jack, and that the knob was attached to a mating plug that acts as an axle.

The kicker is that underneath the audio jack is an AS5600 magnetic encoder, and hidden in a slot milled in the tip of the audio jack is a tiny magnet. Pop the knob into the jack, give it a twist, and you’ve got manual control of your module. Take the knob out, plug in a patch cable, and you can let a control voltage from another module do the job. Genius!

To make it all work mechanically, [Mitxela] had to sandwich a spacer board on top of the main PCB. The spacer has a large cutout to make room for the sensor chip so the magnet can rotate without hitting anything. He also added a CH32V003 to run the encoder and drive the LEDs to provide feedback for the knob-jack. The video below has a brief demo.

This is just a proof of concept, to be sure, but it’s still pretty slick. Almost as slick as [Mitxela]’s recent fluid-motion simulation pendant, or his dual-wielding soldering irons.

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Hacking Digital Calipers For Automated Measurements And Sorta-Micron Accuracy

March 6, 2025 by 14 Comments

We’ll take a guess that most readers have a set of digital calipers somewhere close to hand right now. The cheapest ones tend to be a little unsatisfying in the hand, a bit crusty and crunchy to use. But as [Matthias Wandel] shows us, these budget tools are quite hackable and a lot more precise than they appear to be.

[Matthias] is perhaps best known around these parts for making machine tools using mainly wood. It’s an unconventional material for things like the CNC router he loves to hate, but he makes it work through a combination of clever engineering and a willingness to work within the limits of the machine. To assess those limits, he connected some cheap digital calipers to a Raspberry Pi by hacking the serial interface that seems to be built into all of these tools. His particular calipers output a pair of 24-bit words over a synchronous serial connection a couple of times per second, but at a level too low to be read by the Pi. He solved this with a clever resistor ladder to shift the signals to straddle the 1.8 volt transition on the Pi, and after solving some noise problems with a few strategically placed capacitors and some software debouncing, he was gathering data on his Pi.

Although his setup was fine for the measurements he needed to make, [Matthias] couldn’t help falling down the rabbit hole of trying to milk better resolution from the calipers. On paper, the 24-bit output should provide micron-ish resolution, but sadly, the readings seem to fluctuate rapidly between two levels, making it difficult to obtain an average quickly enough to be useful. Still, it’s a good exercise, and overall, these hacks should prove handy for anyone who wants to dip a toe into automated metrology on a budget.

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Lathe Outfitted With Electronic Gearbox

September 19, 2024 by 46 Comments

Running a metal lathe is not for the faint of heart. Without proper knowledge and preparation, these machines can quickly cause injury or destroy expensive stock, tools, or parts. The other major problem even for those with knowledge and preparedness is that some of their more niche capabilities, like cutting threads with a lead screw, can be tedious and complicated thanks to the change gear system found on some lathes. While these are useful tools for getting things done, [Not An Engineer] decided that there was a better way and got to work building an electronic gearbox to automate the task of the traditional mechanical change gear setup in this video.

What makes change gears so tricky is that they usually come as a set of many gears of different ratios, forcing the lathe operator to figure out the exact combination of gears needed to couple the spindle of the lathe to the feed screw at the precise ratio needed for cutting a specific thread pattern. It is possible to do this task but can be quite a headache. [Not An Engineer] first turned to an Arduino Nano to receive input from a rotary encoder connected to the shaft of the lathe and then instruct a motor to turn the feed screw at a set ratio.

The first major problem was that the Arduino was not nearly fast enough to catch every signal from the encoder, leading to a considerable amount of drift in the output of the motor. That was solved by upgrading to a Teensy 4.1 with a 600 MHz clock speed. There was still one other major hurdle to cross; the problem of controlling the motor smoothly when an odd ratio is selected. [Not An Engineer] used this algorithm to inspire some code, and with that and some custom hardware to attach everything to the lathe he has a working set of electronic change gears that never need to be changed again. And, if you don’t have a lathe at all but are looking to get started with one, you can always build your own from easily-sourced parts.

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Electronic Etch-A-Sketch, No Microcontroller Required

June 20, 2024 by 8 Comments

In a lot of ways, Etch-A-Sketch is the perfect toy; simple, easy to use, creative, endlessly engaging, and as a bonus, it’s completely mechanical. We find that last attribute to be a big part of its charm, but that’s not to say an electronic version of the classic toy can’t be pretty cool, especially when it’s done without the aid of a microcontroller.

This is one of those “because I can” projects that we always find so interesting, and more so because it wasn’t entirely clear to [BigZaphod] that he had the skills to pull it off. While his initial design centered around a bunch of 8×8 LED matrix displays and a 256×4-bit RAM chip, the rest of it was a lot of hand-waving. After a few experiments with addressing the LEDs, [Zaphod] started filling in the blanks with a refresh circuit using a 555 — naturally — and a pair of counters. Properly debounced encoders for the horizontal and vertical controls came next, along with more counters to track the cursor and a host of other circuits that ended up looking like a “one of each” selection from the 7400-series catalog.

While we do wish for a schematic on this one, it’s still a pretty enjoyable video, and the end product seems to work really well. The electronic version has a few features the original lacks, such as wrapping the cursor to the other side of the screen. We’d imagine that the buttons on the encoders could be put to work, too; perhaps a click could make it so you can move the cursor without leaving a trail behind. That might be a challenge to execute in logic, but then again, that was the point of the whole thing.

Still jonesing for that mechanical Etch-A-Sketch experience? Not a problem.

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