Turn A Mouse Into An Analogue Tuning Knob

September 27, 2024 by Jenny List 4 Comments

The software defined radio has opened up unimaginable uses of the radio spectrum for radio enthusiasts, but it’s fair to say that there’s one useful feature of an old-fashioned radio they lack when used via a computer. We’re talking of course about the tuning knob, because it represents possibly the most intuitive way to move across the bands. Never fear though, because [mircemk] has a solution. He’s converted a mouse into a tuning dial.

The scroll wheel on a mouse is nothing more than a rotary encoder, and can easily be used as a sort of tuning knob. Replacing it with a better encoder gives it a much better feel, so that’s what he’s done. An enclosure has the guts of a mouse, with the front-mounted encoder wired into where the scroll wheel would have been. The result, for a relatively small amount of work, is a tuning knob, and a peripheral we’re guessing could also have a lot of uses beyond software defined radio.

It’s not the first knob we’ve seen, for that you might want to start with the wonderfully named Tiny Knob, but it’s quite possibly one of the simplest to build. We like it.

Retro Inspired Cyberdeck Scrolls Around Cyberspace

July 25, 2024 by Tom Nardi 24 Comments

It’s difficult to nail down exactly what counts as a “real” cyberdeck in this brave new era of bespoke computing. But at the minimum, most in the community would agree that a proper deck should have a non-traditional form factor, and be designed to meet the unique needs of the builder. If you’re looking for a fantastic example of both concepts, check out the Cyberdore 2064 from [Tommi L].

At first glance the 3D printed enclosure of the Cyberdore looks a bit like a Speak & Spell, but it’s really more of an amalgamation of everything that made 1980s computers so unique. You’ve got the vents, the chunky switches, the undersized display, and of course, the handle. The case might have been extruded in 2024, but it’s doing a fantastic impression of a piece of tech from 40 years ago.

One of the key external features of the Cyberdore 2064 is the side-mounted rotary encoder that allows for smoothly scrolling through online feeds (such as your favorite hardware hacking site) or long documents. The cheap and easy to work with KY-040 encoder has been converted to a USB input device by way of a Pi Pico, and has been paired with an over-sized 3D printed knob that really makes this build stand out — not only visually, but in terms of usability. These cyberdeck builds often rely on touch screens for input, but we always appreciate a physical interface.

Under the hood you’ve got a Raspberry Pi Zero and an 18650 cell to keep the whole thing running while on the go. Though the Zero is certainly showing its age compared to the more modern variants of the Pi, for a device like this, raw computing power isn’t really the driving concern. A mechanical keyboard usually rounds out these cyberdeck builds, but in this case, [Tommi] went with a fairly common Rii 518BT portable board that’s been skillfully integrated into the front of the Cyberdore.

All of the STL files necessary to print out your own Cyberdore 2064 are available on Printables, and while [Tommi] didn’t exactly provide build instructions, the write-up provides plenty of information to get you started.

So is it just us, or does looking at Cyberdore 2064 make you think it’s time for another Hackaday Cyberdeck Challenge?

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Foot Keyboard

October 25, 2023 by Kristina Panos 12 Comments

[crispernaki]’s opening comments to this VCR head scroll wheel project lament that overall technical details aren’t “complex, ground-breaking, or even exciting.” Since when does that matter? The point is that not only did the thing finally, eventually get built, it gets daily use and it sparks joy in its owner.

This feel-good story is one of procrastination, laziness, and one aha! moment, and it’s roughly twelve years in the making. Inspired by an Instructable from long ago, [crispernaki] ran straight to the thrift store to get a VCR and take it apart.

The original plan was to just reuse the VCR head’s PCB and hide it in an enclosure, and then figure out way to block and unblock the path between an IR emitter/receiver pair. After many disemboweled mice and fruitless attempt, the project was once again shelved.

But then, [crispernaki] remembered the magnetic rotary encoder demo board that was just sitting around, along with various microcontrollers and Altoids tins. And it all quickly came together with a Teensy 2.0 and some bits and bobs, including a magnet glued on the shaft of the VCR head. A chip on the demo board does all the heavy lifting, and of course, the Teensy does the work of emulating an HID.

Continue reading “Keebin’ With Kristina: The One With The Foot Keyboard” →

A view of the inside of a car, with drivers wheel on the left and control panel in the middle, with red LED light displayed in the floor area under the drivers wheel and passenger side.

Bass Reactive LEDs For Your Car

April 25, 2023 by Abe Connelly 32 Comments

[Stephen Carey] wanted to spruce up his car with sound reactive LEDs but couldn’t quite find the right project online. Instead, he wound up assembling a custom bass reactive LED display using an ESP32.

The entirety of the build is minimal, consisting of a GY-MAX4466 electret microphone module, a KY-040 encoder for some user control and an ESP32 attached to a Neopixel strip. The only additional electronic parts are some passive resistors to limit current on the data lines and a capacitor for power line noise suppression. [Stephen] uses various enclosures from Thingiverse for the microphone, rotary encoder and ESP32 box to make sure all the modules are protected and accessible.

The magic, of course, is in the software, with the CircuitPythyon ulab library used to do the heavy lifting of creating the spectrogram and frequency filtering. [Stephen] has made the code is available on GitHub for those wanting to take a closer look.

It wasn’t very long ago that sound reactive LEDs used to be a heavy lift, requiring optimized FFT libraries or specialized components to do the spectrogram. With faster and cheaper microcontroller boards, we’re seeing many great projects, like the sensory bridge or Raspberry Pi driven LED spectrogram, that can now take spectrograms and Fourier transform calculations as basic infrastructure to build on top of them. We’re happy to see [Stephen] leverage the ESP32’s speed and various circuit Python libraries to create a very cool LED car hack.

Video after the break!

Continue reading “Bass Reactive LEDs For Your Car” →

Kitchen timer project in a angled green 3d printed case with a 7 segment display and knob.

Printing A Brutalist Kitchen Timer

April 2, 2023 by Abe Connelly 23 Comments

A kitchen timer is one of those projects that’s well defined enough to have a clear goal, but allows plenty of room for experimentation with functionality and aesthetics. [Hggh]’s exploration of the idea is a clean, Brutalist kitchen timer.

The case for [Hggh]’s kitchen timer is 3D printed with openings for a TM1637 four digit, seven segment display and for a KY-040 rotary encoder with knob attached. The internals are driven by an ATmega328P powered from a 18650 cell with a DW01-P battery protection chip and a TP4056 chip for charging. On the back of the case is a power switch and USB-C connector for power. It looks like the 3D printed case was sanded down to give it a smooth matte surface finish.

All the project files, including the STLs, OpenSCAD code, and KiCAD design, are available on GitHub. This Brutalist kitchen timer project is a nice addition to some of the kitchen timers we’ve featured in the past, including a minimalist LED matrix timer and a Nixie timer with keypad.

DIY Arduino Hearing Test Device

October 23, 2022 by Dave Walker 18 Comments

Hearing loss is a common problem for many – especially those who may have attended too many loud concerts in their youth. [mircemk] had recently been for a hearing test, and noticed that the procedure was actually quite straightforward. Armed with this knowledge, he decided to build his own test system and document it for others to use.

audiogram showing the results of the arduino hearing test device — Resultant audiogram from the device showing each ear in a different color

By using an Arduino to produce tones of various stepped frequencies, and gradually increasing the volume until the test subject can detect the tone, it is possible to plot an audiogram of hearing threshold sensitivity. Testing each ear individually allows a comparison between one side and the other.

[mircemk] has built a nice miniature cabinet that holds an 8×8 matrix of WS2812 addressable RGB LEDs. A 128×64 pixel OLED display provides user instructions, and a rotary encoder with push-button serves as the user input.

Of course, this is not a calibrated professional piece of test equipment, and a lot will depend on the quality of the earpiece used. However, as a way to check for gross hearing issues, and as an interesting experiment, it holds a lot of promise.

There is even an extension, including a Class D audio amplifier, that allows the use of bone-conduction earpieces to help narrow down the cause of hearing loss further.

There’s some more information on bone conduction here, and we’ve covered an intriguing optical stimulation cochlear implant, too.

Continue reading “DIY Arduino Hearing Test Device” →

A Rotary Encoder: How Hard Can It Be?

April 20, 2022 by Al Williams 70 Comments

As you may have noticed, I’ve been working with an STM32 ARM CPU using Mbed. There was a time when Mbed was pretty simple, but a lot has changed since it has morphed into Mbed OS. Unfortunately, that means that a lot of libraries and examples you can find don’t work with the newer system.

I needed a rotary encoder — I pulled a cheap one out of one of those “49 boards for Arduino” kits you see around. Not the finest encoder in the land, I’m sure, but it should do the job. Unfortunately, Mbed OS doesn’t have a driver for an encoder and the first few third-party libraries I found either worked via polling or wouldn’t compile with the latest Mbed. Of course, reading an encoder isn’t a mysterious process. How hard can it be to write the code yourself? How hard, indeed. I thought I’d share my code and the process of how I got there.

There are many ways you can read a rotary encoder. Some are probably better than my method. Also, these cheap mechanical encoders are terrible. If you were trying to do precision work, you should probably be looking at a different technology like an optical encoder. I mention this because it is nearly impossible to read one of these flawlessly.

So my goal was simple: I wanted something interrupt driven. Most of what I found required you to periodically call some function or set up a timer interrupt. Then they built a state machine to track the encoder. That’s fine, but it means you eat up a lot of processor just to check in on the encoder even if it isn’t moving. The STM32 CPU can easily interrupt with a pin changes, so that’s what I wanted.

The Catch

The problem is, of course, that mechanical switches bounce. So you have to filter that bounce either in hardware or software. I really didn’t want to put in any extra hardware more than a capacitor, so the software would have to handle it.

I also didn’t want to use any more interrupts than absolutely necessary. The Mbed system makes it easy to handle interrupts, but there is a bit of latency. Actually, after it was all over, I measured the latency and it isn’t that bad — I’ll talk about that a little later. Regardless, I had decided to try to use only a pair of interrupts.

Continue reading “A Rotary Encoder: How Hard Can It Be?” →