BenchVolt PD: USB PD Meets Benchtop Precision

October 10, 2025 by Matt Varian 36 Comments

USB power has become ubiquitous — everything from phones to laptops all use it — so why not your lab bench? This is what [EEEngineer4Ever] set out to do with the BenchVolt PD USB adjustable bench power supply. This is more than just a simple breakout for standard USB PD voltages, mind you; with adjustable voltages, SCPI support, and much more.

The case is made of laser-cut acrylic, mounted to an aluminum base, not only providing a weighted base but also helping with dissipating heat when pulling the 100 W this is capable of supplying. Inside the clear exterior, not only do you get to peek at all the circuitry but there is also a bright 1.9-inch TFT screen showing the voltage, current, and wattage of the various outputs. There is a knob that can adjust the variable voltage output and navigate through the menu. Control isn’t limited to the knob, mind you; there also is a Python desktop application to make it easy changing the settings and to open up the possibility to integrate its control alongside other automated test equipment.

There are five voltage outputs in this supply: three fixed ones—1.8 V, 2.5 V, and 3.3 V—and two adjustable ones: 0.5-5 V and 2.5-32 V. All five of these outputs are capable of up to 3 A. There are also a variety of waveforms that can be output, blurring the lines between power supply and function generator. While the BenchVolt PD will be open-sourced, [EEEngineer4Ever] will soon be releasing it over on CrowdSupply for those interested in one without building one themselves. We are big fans of USB PD gear, so be sure to check out some other USB PD projects we’ve featured.

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Splashflag: Raising The Flag On A Pool Party

October 5, 2025 by Matt Varian 7 Comments

Some things are more fun when there are more folks involved, and enjoying time in the pool is one of those activities. Knowing this, [Bert Wagner] started thinking of ways to best coordinate pool activities with his kids and their neighborhood friends. Out of this came the Splashflag, an IoT device built from the ground up that provides fun pool parties and a great learning experience along the way.

The USB-powered Splashflag is housed in a 3D-printed case, with a simple 2×16 LCD mounted on the front to display the notification. There’s also a small servo mounted to the rear that raises a 3D-printed flag when the notification comes in—drawing your attention to it a bit more than just text alone would. Hidden on the back is also a reset button: a long press factory-resets the device to connect to a different Wi-Fi network, and a quick press clears the notification to return the device to its resting state.

Inside is an ESP32-S3 that drives the servo and display and connects to the Wi-Fi. The ESP32 is set up with a captive portal, easing the device’s connection to a wireless network. The ESP32, once connected, joins an MQTT broker hosted by [Bert Wagner], allowing easy sending of notifications via the web app he made to quickly and easily send out invitations.

Thanks, [Bert Wagner], for sharing the process of building this fun, unique IoT device—be sure to read all the details on his website or check out the code and design files available over on his GitHub. Check out some of our other IoT projects if this project has you interested in making your own.

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Cold Sensor, Hot Results: Upgrading A DSLR For Astrophotography

October 3, 2025 by Matt Varian 16 Comments

When taking pictures of the night sky, any noise picked up by the sensor can obscure the desired result. One major cause of noise in CMOS sensors is heat—even small amounts can degrade the final image. To combat this, [Francisco C] of Deep SkyLab retrofitted an old Canon T1i DSLR with an external cooler to reduce thermal noise, which introduces random pixel variations that can hide faint stars.

While dedicated astrophotography cameras exist—and [Francisco C] even owns one—he wanted to see if he could improve an old DSLR by actively cooling its image sensor. He began with minor surgery, removing the rear panel and screen to expose the back of the sensor. Using a sub-$20 Peltier cooler (also called a TEC, or Thermoelectric Cooler), he placed its cold side against the sensor, creating a path to draw heat away.

Reassembling the camera required some compromises, such as leaving off the LCD screen due to space constraints. To prevent light leaks, [Francisco C] covered the exposed PCBs and viewfinder with tape. He then tested the setup, taking photos with the TEC disabled and enabled. Without cooling, the sensor started at 67°F but quickly rose to 88°F in sequential shots. With the TEC enabled, the sensor remained steady at 67°F across all shots, yielding a 2.8x improvement in the signal-to-noise ratio. Thanks to [Francisco C] for sharing this project! Check out his project page for more details, and explore our other astrophotography hacks for inspiration.

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Mandrel Magic: Small Box Assembly With 3D Printing

September 21, 2025 by Matt Varian 2 Comments

Often, we face tedious tasks with no way around them. Sometimes, you just have to grit your teeth and push through. But small tweaks can make the onerous task a bit easier to handle. [James Bowman] sent in his latest quick project that helps him fold small boxes more efficiently.

To fulfill orders on his previously covered TermDriver2, [James Bowman] is faced with folding thousands of small boxes. To aid in this daunting task, he had the idea of making a tool to streamline the process — every second saved adds up when you’re repeating a task thousands of times. He designed a 3D printed mandrel that pops the flat box blank open as it’s slid over the tapered top, shaping it into a perfect rectangle for easy folding of the top flaps.

The nice thing about 3D printng is how easy it is to iterate on a design. Once James had the first version printed and verified it worked as hoped, he had ideas to improve it, such as adding a second mandrel to twist the box from both the inside and outside and adding a guide on one side to enhance rigidity.

While we often think of 3D printers producing ready-to-use parts, but printed tooling holds great potential for repetitive tasks, and is a huge cost saver compared to traditional methods.

DIY electronic eyepiece viewfinder for telescope

Low-Cost, High-Gain: A Smart Electronic Eyepiece For Capturing The Cosmos

September 21, 2025 by Matt Varian 18 Comments

We’ve all seen spectacular pictures of space, and it’s easy to assume that’s how it looks to the naked eye through a nice telescope. But in most cases, that’s simply not true. Space is rather dark, so to make out dim objects, you’ll need to amplify the available light. This can be done with a larger telescope, but that’s an expensive route. Alternatively, you can observe objects for longer periods. This second approach is what [Jordan Blanchard] chose, creating a budget electronic eyepiece for his telescope.

This eyepiece is housed in a 3D printed enclosure designed to fit a standard 1.25″ telescope focuser. The sleek, ergonomic enclosure resembles a night vision device, with a 0.39″ screen for real-time observation of what the camera captures through the telescope. The screen isn’t the only way to view — a USB-C video capture module lets you connect a phone or computer to save images as if you were peering through the viewfinder.

The star of this project is the IMX307 camera module, which supports sense-up mode for 1.2-second exposures and increased gain to capture dim objects without post-processing. This sensor, commonly used in low-light security cameras and dash cams, excels at revealing faint celestial details. All combined, this project cost under 200 Euros, an absolute steal in the often pricey world of astronomy.

Don’t have a telescope? Don’t worry, you can build one of those as well.

USB-C PD Decoded: A DIY Meter And Logger For Power Insights

September 15, 2025 by Matt Varian 9 Comments

As USB-C PD becomes more and more common, it’s useful to have a tool that lets you understand exactly what it’s doing—no longer is it limited to just 5 V. This DIY USB-C PD tool, sent in by [ludwin], unlocks the ability to monitor voltage and current, either on a small screen built into the device or using Wi-Fi.

This design comes in two flavors: with and without screen. The OLED version is based on an STM32, and the small screen shows you the voltage, current, and wattage flowing through the device. The Wi-Fi PD logger version uses an ESP-01s to host a small website that shows you those same values, but with the additional feature of being able to log that data over time and export a CSV file with all the collected data, which can be useful when characterizing the power draw of your project over time.

Both versions use the classic INA219 in conjunction with a 50 mΩ shunt resistor, allowing for readings in the 1 mA range. The enclosure is 3D-printed, and the files for it, as well as all the electronics and firmware, are available over on the GitHub page. Thanks [ludwin] for sending in this awesome little tool that can help show the performance of your USB-C PD project. Be sure to check out some of the other USB-C PD projects we’ve featured.

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From Paper To Pixels: A DIY Digital Barograph

September 14, 2025 by Matt Varian 6 Comments

A barograph is a device that graphs a barometer’s readings over time, revealing trends that can predict whether stormy weather is approaching or sunny skies are on the way. This DIY Digital Barograph, created by [mircmk], offers a modern twist on a classic technology.

Dating back to the mid-1700s, barographs have traditionally used an aneroid cell to move a scribe across paper that advances with time, graphing pressure trends. However, this method has its shortcomings: you must replace the paper once it runs through its time range, and mechanical components require regular maintenance.

[mircmk]’s DIY Digital Barograph ditches paper and aneroids for a sleek 128×64 LCD display that shows measurements from a BME280 pressure sensor. Powered by an ESP32 microcontroller — the code for which is available on the project page — the device checks the sensor upon boot and features external buttons to cycle through readings from the current moment, the last hour, or three hours ago. Unlike traditional barographs that only track pressure, the BME280 also measures temperature and humidity, which are displayed on the screen for a more complete environmental snapshot.

Head over to the project’s Hackaday.io page for more details and to start building your own. Thanks to [mircmk] for sharing this project! We’re excited to see what you come up with next. If you’re inspired, check out other weather display projects we’ve featured.

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