Linamp, The IRL Winamp

June 6, 2024 by Dan Maloney 60 Comments

Anyone who first experienced music on computers using Winamp probably shares a memory of seeing that classic UI for the first time. Everything about it was a step ahead of the clunky, chunky interfaces we were used to, and even though it was supposed to be unobtrusive, it was hard to tear your eyes off that silky-smooth spectrum analyzer bouncing out your favorite MP3s.

Recapturing a little of the Winamp magic is the goal of Linamp, an physical version of the classic media player. It reproduces the Winamp UI on a touchscreen LCD with a wide aspect ratio that almost perfectly matches the original layout. Behind the display is a Raspberry Pi 4 with a 32 GB SD card, with all the important connections brought out to a board on the back of the case. The case itself is a treat, as it borrows design elements from another bit of retro gear, the mini-rack audio systems that graced many a bookshelf in the 1980s — and powered many high school parties too, if memory serves.

To recreate the case, [Rodmg] designed a sheet metal case and had it custom-made from anodized aluminum by PCBWay. He also printed a bezel for the display that looks very similar to the Winamp window border, complete with control icons. Where the build really shines, though, is with the work [Rodmg] put into the software. He matched the original Winamp UI very closely, both in terms of layout and performance. The pains he went to to get the spectrum analyzer working, including a deep dive into FFT, are impressive.

The results speak for themselves on this one, and hats off to [Rodmg] for the effort and the ride on the nostalgia train. We don’t know if the recent announcement of Winamp’s impending open-sourcing will have much impact on this project, but it might result in a flood of new Winamp builds.

USB Dongle Brings Python-Controlled GPIO To The Desktop

June 5, 2024 by Dan Maloney 25 Comments

Microcontroller dev boards are wonderfully useful items, in testament to which most of us maintain an ample collection of the things. But dragging one out to do a simple job can be a pain, what with making sure you have the whole toolchain set up to support the device, not to mention the inevitable need to solder or desolder header pins. Wouldn’t it be nice if there was a simple plug-and-play way to add a few bits of GPIO to your desktop or laptop machine?

[Nick Bild] thinks so, and came up with the USBgpio. The hardware in the dongle is pretty much what you’d expect — an Arduino Nano 33 IoT. Yes, you could just bust out a Nano and do this yourself, but [Nick] has done all the heavy lifting already. Eleven of the Nano’s IO pins plus 3.3V and ground are broken out to header pins that stick out of the 3D-printed enclosure, and the dongle is powered over the USB cable. [Nick] also built a Python library for the USBgpio, making it easy to whip up a quick program. You just import the library, define the serial port and baud rate, and the library takes care of the rest. The video below shows a quick blinkenlight test app.

Earth-shattering stuff? Perhaps not; [Nick] admits as much by noting the performance doesn’t really dazzle. But that’s hardly the point of the project, and if you need a couple of pins of IO on the desktop for a quick tactical project or some early-stage prototyping, USBgpio could be your friend. Continue reading “USB Dongle Brings Python-Controlled GPIO To The Desktop” →

Gamma Ray Spectroscopy The Pomelo Way

June 5, 2024 by Dan Maloney 15 Comments

Depending on the circumstances you find yourself in, a Geiger counter can be a tremendously useful tool. With just a click or a chirp, it can tell you if any invisible threats lurk. But a Geiger counter is a “yes or no” instrument; it can only tell you if an ionizing event occurred, revealing nothing about the energy of the radiation. For that, you need something like this gamma-ray spectroscope.

Dubbed the Pomelo by [mihai.cuciuc], the detector is a homebrew solid-state scintillation counter made from a thallium-doped cesium iodide crystal and a silicon photomultiplier. The scintillator is potted in silicone in a 3D printed enclosure, to protect the hygroscopic crystal from both humidity and light. There’s also a temperature sensor on the detector board for thermal compensation. The Pomelo Core board interfaces with the physics package and takes care of pulse shaping and peak detection, while a separate Pomelo Zest board has an ESP32-C6, a small LCD and buttons for UI, SD card and USB interfaces, and an 18650 power supply. Plus a piezo speaker, because a spectroscope needs clicks, too.

The ability to determine the energy of incident photons is the real kicker here, though. Pomelo can detect energies from 50 keV all the way up to 3 MeV, and display them as graphs using linear or log scales. The short video below shows the Pomelo in use on samples of radioactive americium and thorium, showing different spectra for each.

[mihai.cuciuc] took inspiration for the Pomelo from this DIY spectrometer as well as the CosmicPi.

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Mining And Refining: Fracking

June 5, 2024 by Dan Maloney 53 Comments

Normally on “Mining and Refining,” we concentrate on the actual material that’s mined and refined. We’ve covered everything from copper to tungsten, with side trips to more unusual materials like sulfur and helium. The idea is to shine a spotlight on the geology and chemistry of the material while concentrating on the different technologies needed to exploit often very rare or low-concentration deposits and bring them to market.

This time, though, we’re going to take a look at not a specific resource, but a technique: fracking. Hydraulic fracturing is very much in the news lately for its potential environmental impact, both in terms of its immediate effects on groundwater quality and for its perpetuation of our dependence on fossil fuels. Understanding what fracking is and how it works is key to being able to assess the risks and benefits of its use. There’s also the fact that like many engineering processes carried out on a massive scale, there are a lot of interesting things going on with fracking that are worth exploring in their own right.
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Thermoelectric Module Keeps Printer Filament Cool And Dry

June 5, 2024 by Dan Maloney 59 Comments

Anyone who has left their car windows open during a rainstorm will tell you the best way to dry the upholstery is to crank the AC and close the windows. A couple of hours later, presto — dry seats. The same can be said for 3D printer filament, and it’s pretty much what [Ben Krejci] is doing with this solid-state filament dryer.

The running gear for this build is nothing fancy; it’s just a standard thermoelectric cooling module and a fan. The trick was getting the airflow over the module right. [Ben] uses two air inlets on his printed enclosure to pull air from the cold side of the Peltier, which allows the air enough time in contact with the cold to condense out the water. It also allows sufficient airflow to keep the hot side of the module from overheating.

Water collection was a challenge, too. Water always finds a way to leak, and [Ben] came up with a clever case design incorporating a funnel to direct water away. The module is also periodically run in reverse to defrost the cold side heatsink.

The dehumidifier lives in a large tool cabinet with plenty of room for filament rolls and is run by an ESP32-C3 with temperature and humidity sensors, which allowed [Ben] to farm most of the control and monitoring out to ESPHome. The setup seems to work well, keeping the relative humidity inside the cabinet in the low 20s — good enough for PETG and TPU.

It’s an impressively complete build using off-the-shelf parts. For a different approach to solid-state filament drying, check out [Stefan]’s take on the problem.

Old Dot-Matrix Displays Give Up Their Serial Secrets

June 4, 2024 by Dan Maloney 11 Comments

If there’s one thing we like better around here than old, obscure displays, it’s old, obscure displays with no documentation that need a healthy dose of reverse engineering before they can be put to use. These Plessey dot-matrix displays are a perfect example of that.

We’re not sure where [Michael] scored these displays, but they look fantastic. Each 8-pin DIP has two 5×7-matrix, high-visibility LED displays. They bear date codes from the late 80s under the part number, GPD340, but sadly, precious little data about them could be dredged up from the Interwebz. With 70 pixels and only six pins after accounting for power and ground, [Michael] figured there would be a serial protocol involved, but which pins?

He decided to brute-force the process of locating them, using a Pico to sequentially drive every combination while monitoring the current used with a current sensor. This paid off after only a few minutes, revealing that each character of the display has its own clock and data pins. The protocol is simple: pull the clock and data pins high then send 35 bits, which the display sorts out and lights the corresponding pixels. The video below shows a 12-character scrolling display in action.

Plessey made a lot of displays for military hardware, and these chunky little modules certainly have a martial air about them. Given that and the date code, these might have come from a Cold War-era bit of military hardware, like this Howitzer data display which sports another Plessey-made display.

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Hackaday Links: June 2, 2024

June 2, 2024 by Dan Maloney 6 Comments

So you say you missed the Great Solar Storm of 2024 along with its attendant aurora? We feel you on that; the light pollution here was too much for decent viewing, and it had been too long a day to make a drive into the deep dark of the countryside survivable. But fear not — the sunspot that raised all the ruckus back at the beginning of May has survived the trip across the far side of the sun and will reappear in early June, mostly intact and ready for business. At least sunspot AR3664 seems like it’s still a force to be reckoned with, having cooked off an X-class flare last Tuesday just as it was coming around from the other side of the Sun. Whether 3664 will be able to stir up another G5 geomagnetic storm remains to be seen, but since it fired off an X-12 flare while it was around the backside, you never know. Your best bet to stay informed in these trying times is the indispensable Dr. Tamitha Skov.

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