A capacitive touch MIDI instrument that doubles as a bookmark.

MIDI Bookmark Marks The Spot Where Work And Play Intersect

May 6, 2024 by Kristina Panos 3 Comments

Have you ever wanted to take a break from reading or studying to just rock out for a few blissful minutes? If you’re anything like us, you like to rock out most of the time and take the occasional break to do your reading. Either way, you really can’t go wrong with this MIDI bookmark from [Misfit Maker].

This slick little bookmark may look 3D printed, but it’s all carefully-cut foam board in two thicknesses. Even the keys are made foam board — they’re just wrapped in carbon fiber so they look extra cool.

Underneath that carbon fiber is a layer of aluminium tape to make them capacitive. [Misfit Maker] recommends using copper tape instead because it allows for wires to be soldered directly to the keys.

The brains of this beauty is in the form of an ESP32 which is controlling an MPR-121 capacitive touch sensor. If you’d like to make one of these for yourself, there are plenty of helpful GIFs embedded in the thorough write-up. Be sure to check out the brief demo after the break.

If you want to easily MIDI-fy something and use touch inputs, you can’t really go wrong with the Raspberry Pi Pico, which does capacitive touch natively. Check out this MIDI kalmiba to learn more.

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A beehive sits on bricks with an outdoor-rated box full of electronics to monitor the hive.

Hive Monitor Is The Bee’s Knees

May 5, 2024 by Kristina Panos 11 Comments

Beekeeping is quite the rewarding hobby. There’s delicious honey and useful wax to be had, plus you get the honor of knowing that you’re helping to keep the bee population surviving and thriving. [Ben Brooks] likes to keep tabs on the hive, but doesn’t like the idea of opening it up more often than necessary. After a couple of beekeeping rodeos, [Ben] decided to build his own tracker to get reports on the health and the activity of the hive through Home Assistant.

This hive tracker features a light sensor, a temperature sensor, and three strain gauges to measure the weight. There would be four, but a mouse decided to take a bite of the wires in the most nightmarish place to repair.

Everything runs off of an ESP32, and there’s an external antenna involved because the hive is nearly out of Wi-Fi range. The strain gauges are the affordable bathroom-scale type, and [Ben] has extras for if and when the number of hives goes up.

We like the combination of hard work and simplicity going on here — [Ben] milled and drilled the PCB himself, and used phone plugs to connect the temperature and weight sensors. Unfortunately, the plugs make the strain gauges a little finicky, so [Ben] says he would probably use screw terminals next time, or might be soldering the wires sooner rather than later. Consider this one a work in progress, and keep watching for updates as [Ben] works out the kinks.

Interested in beekeeping, but don’t want to build a traditional hive? Check out this beehive in a bottle.

Singleboard: Alpha Is A Very Stylish Computer On A Single PCB

April 30, 2024 by Lewin Day 34 Comments

When we think single-board computers, we normally envision things like the Raspberry Pi. But Arduboy creator [Kevin Bates] has recently come up with his own take on the SBC that’s a bit like a modernized take on the early computers of the 1980s. Introducing Singleboard: Alpha.

The build has an incredibly pleasing form factor — it’s a single PCB with a capacitive keyboard etched right into the copper. The brains of the Singleboard is an ESP32, which provides plenty of grunt as well as wireless connectivity. Display is via a small LCD, currently configured with a green-on-black terminal that looks fantastic.

You’re not gonna run a fully-fledged GUI operating system on this thing, but that doesn’t mean it can’t be useful. We could imagine a device like this being a flexible wireless terminal for working with headless systems, for example, and it would be a charming one at that.

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Keep Tabs On PC Use With Custom Analog Voltmeter

April 26, 2024 by Bryan Cockfield 8 Comments

With the demands of modern computing, from video editing, streaming, and gaming, many of us will turn to a monitoring system of some point to keep tabs on CPU usage, temperatures, memory, and other physical states of our machines. Most are going to simply display on the screen but this data can be sent to external CPU monitors as well. This retro-styled monitor built on analog voltmeters does a great job of this and adds some flair to a modern workstation as well.

The build, known as bbMonitor, is based on the ESP32 platform which controls an array of voltmeters via PWM. The voltmeters have been modified with a percentage display to show things like CPU use percentage. Software running on the computers sends this data in real time to the ESP32 so the computer’s behavior can be viewed at a glance. Each voltmeter is also augmented with RGB LEDs that change color from green to red as use increases as well. The project’s creator, [Corebb], also notes that the gauges will bounce around if the computer is under heavy load but act more linearly when under constant load, also helping to keep an eye on computer status.

While the build does seem to rely on a Windows machine to run the software for export to the monitor, all of the code is open-sourced and available on the project’s GitHub page and could potentially be adapted for other operating systems. And, as far as the voltmeters themselves go, there have been similar projects in the past that use stepper motors as a CPU usage monitor instead.

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A Smart Power Distribution Unit For Home Automation

April 25, 2024 by Bryan Cockfield 28 Comments

Power distribution units, as the name implies, are indispensable tools to have available in a server rack. They can handle a huge amount of power for demands of intensive computing and do it in a way that the wiring is managed fairly well. Plenty of off-the-shelf solutions have remote control or automation capabilities as well, but finding none that fit [fmarzocca]’s needs or price range, he ended up building his own essentially from scratch that powers his home automation system.

Because it is the power supply for a home automation system, each of the twelve outlets in this unit needed to be individually controllable. For that, three four-channel relay boards were used, each driven by an output on an ESP32. The ESP32 is running the Tasmota firmware to keep from having to reinvent the wheel, while MQTT was chosen as a protocol for controlling these outlets to allow for easy integration with the existing Node-RED-based home automation system. Not only is control built in to each channel, but the system can monitor the power consumption of each outlet individually as well. The entire system is housed in a custom-built sheet metal enclosure and painted to blend in well with any server rack.

Adding a system like this to a home automation system can simplify a lot of the design, and the scalable nature means that a system like this could easily be made much smaller or much larger without much additional effort. If you’d prefer to keep your hands away from mains voltage, though, we’ve seen similar builds based on USB power instead, with this one able to push around 2 kW.

Supercon 2023: Alex Lynd Explores MCUs In Infosec

April 24, 2024 by Tom Nardi 9 Comments

The average Hackaday reader hardly needs to be reminded of the incredible potential of the modern microcontroller. While the Arduino was certainly transformative when it hit the scene, those early 8-bit MCUs were nothing compared to what’s on the market now. Multiple cores with clock speeds measured in the hundreds of megahertz, several MB of flash storage, and of course integrated WiFi capability mean today’s chips are much closer to being fully-fledged computers than their predecessors.

It’s not hard to see the impact this has had on the electronics hobby. In the early 2000s, getting your hardware project connected to the Internet was a major accomplishment that probably involved bringing some hacked home router along for the ride. But today, most would consider something like an Internet-connected remote environmental monitor to be a good starter project. Just plug in a couple I2C sensors, write a few lines of Python, and you’ve got live data pouring into a web interface that you can view on your mobile device — all for just a few bucks worth of hardware.

But just because we’re keenly aware of the benefits and capabilities of microcontrollers like the ESP32 or the Pi Pico, doesn’t mean they’ve made the same impact in other tech circles. In his talk Wireless Hacking on a $5 Budget, Alex Lynd goes over some examples of how he’s personally put these devices to work as part of his information security (infosec) research.

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Synesthetic Clock Doesn’t Require Synesthesia

April 10, 2024 by Kristina Panos 15 Comments

We often think of synesthetes as those people who associate say, colors with numbers. But the phenomenon can occur with any of the senses. Simply put, when one sense is activated, synesthesia causes one to experience an unrelated, activated sense. Sounds trippy, no?

Thankfully, [Markus Opitz]’s synesthetic clock doesn’t require one to have synesthesia. It’s actually quite easy to read, we think. Can you tell what time it is in the image above? The only real requirement seems to be knowing the AM color from the PM color. The minute display cycles through blue, green, yellow, and red as the hour progresses.

Behind that pair of GC9a01 round displays lies an ESP32 and a real-time clock module. [Markus] couldn’t find a fillArc function, so instead he is drawing triangles whose ends lie outside the visible area. To calculate the size of the triangle, [Markus] is using the angle function tangent, so each minute has an angle of 6°.

[Markus] created a simple but attractive oak housing for the clock, but suggests anything from cardboard and plastic to a book. What’s the most interesting thing you’ve ever used for an enclosure? Let us know in the comments.

Do you appreciate a good analog clock when you see one? Here’s a clock that uses analog meters for its display.