Two pieces of metal are sitting next to each other on a brick, with one edge touching. The copper end of a torch is directing a flame against the metal, and the metal is glowing brightly around the point where the flame contacts it.

Welding With Natural Gas And Oxygen

September 21, 2025 by 15 Comments

By virtue of its triple bond, acetylene burns hotter than any other common hydrocarbon when mixed with oxygen, but it isn’t the only flame hot enough for welding. With the assistance of a homemade oxygen concentrator, [Hyperspace Pirate] was able to make a natural gas torch that melts steel, even if welding with the torch remains difficult.

[Hyperspace Pirate] built his oxygen concentrator around a pressure-swing adsorption system, which uses two tanks of a molecular sieve to selectively adsorb and purge nitrogen, leaving behind mostly oxygen. [Hyperspace Pirate] used reverse-osmosis membrane casings as the tanks, solenoid valves to control gas flow, and an Arduino with some MOSFETs to control the timing. For fuel, he used a convenient source of natural gas, already installed in his garage: the water heater’s gas supply. Since the house’s meter regulates the gas down to a fairly low pressure, and the oxygen concentrator doesn’t produce high pressures, the torch didn’t need any inline regulators.

Inline check valves, on the other hand, were very much necessary, a mixture of oxygen and natural gas propagating back along the lines being undesirable for obvious reasons, and flashback arrestors would have been a good addition. [Hyperspace Pirate] built the torch itself out of copper tubing and needle valves, with a 0.9 mm MIG welder tip as the nozzle. Adjusting the gas mixture was mostly a matter of trial and error. With an oxygen-rich flame, it could cut thin metal decently well, but it tended to melt thick pieces more than it cut. On the other hand, even with a neutral flame, the water vapor in the exhaust oxidized steel, which made welding quite difficult, but not impossible.

The oxygen supply by itself was an entertaining tool, turning smoldering pieces of charcoal or steel wool violently incandescent. With the assistance of some steel wool, [Hyperspace Pirate] set a steel tube on fire. With a bit more oxygen, it would probably make an effective thermic lance. If you still want to do your welding with acetylene, he’s also made that before.

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DIY electronic eyepiece viewfinder for telescope

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

September 21, 2025 by 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.

For A Robot Claw, The Eyes Have It

September 21, 2025 by 3 Comments

Have you ever wished your hand had an extra feature? Like, maybe, a second thumb? A scope probe pinky maybe? Well, if you are building a robot effector, you get to pick what extra features it has. [Gokux] has the aptly named Cam Claw, which is a 3D printed claw with a built-in camera so you can see exactly what it is doing.

The brains are an ESP32-S3 and the eyes — well, the eye technically — uses an OV3660 camera. There’s even a light in case you are in a dark space. A servo drives it, and the printed gear train is pretty fun to watch, as you can see in the video below.

This project is all about the mechanics. The electronic hardware is trivial. A battery, a power controller, and a servo complement the ESP32 and camera. Six LEDs for light, and the job is done.

Obviously, the gripping power will only be as good as the servo. However, we really liked the idea of putting eyes on a robot hand where they count. Of course, the claw you really want a camera on is in the arcade. We’d like to see cameras on some other robot appendages.

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Building A (Not Very) Portable Xbox

September 21, 2025 by 24 Comments

Modern handheld game consoles are impressive feats of engineering, featuring full fledged computers in near pocket-sized packages. So what happens if you take an original Xbox and sprinkle on some modern electronics and create a handheld? Well, if you’re [James] of James Channel, you end up with this sandwich of PCBs held together with hot glue and duck tape. 

The first order of miniaturization in this Xbox was replacing the hard drive. Because a CompactFlash card uses parallel ATA, that could be a simple drop in replacement. However, the Xbox locks the hard drive to the system requiring a mod chip for the CF card to work. Fortunately, the sacrificial Xbox came with a mod chip installed. After using an arcade machine to flash the card and copy over the contents of the drive, the CF card install was a breeze. 

For the screen and batteries, a portable DVD player that had remained unused since 2006 was repurposed. The battery cells were rather unhappy, but managed to get resurrected with some careful charging. As it turns out, the iPod 30 pin connector inside the portable screen contains an S-Video line. By tapping into that and adding in some power management for the batteries, the Xbox became a pile of PCBs that could maybe be taken places.

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March To The Beat Of Your Own Piezoelectric Drum

September 20, 2025 by 7 Comments

Drums! You hit them, and they vibrate. It’s kind of fun. Piezoelectric elements can create electric current when they vibrate. [Will Dana] put two and two together to try and charge his phone on his YouTube channel WillsBuilds embedded below.

It worked… about as well as you might expect. Which is to say: not very well. The random piezo elements [Will] glues to his drum almost certainly aren’t optimized for this use case. Adding weight helps, but it doesn’t look like a tuned system. Even if it was, piezoelectric generators aren’t terribly efficient by nature, and the (small) losses from the required bridge rectifiers aren’t helping. An energy-harvesting chip might have worked better, but it probably wouldn’t have worked well.

Since he cannot produce enough voltage in real time, [Will] opts to charge a capacitor bank that he can dump into the phone once it gets enough charge in it to register with the phone’s circuitry. It takes about 30 minutes drumming to charge the capacitors in parallel, before switching to series to get the voltage up to discharge. The capacitors drain in about a quarter second, probably to no measurable result– but the phone does read as “charging”, which was the goal.

Did it work? Technically, yes. The phone was “charging”. Is it practical? Certainly not. Is it a hack? Undeniably so.

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When Low SRAM Keeps The DOOM Off Your Vape

September 20, 2025 by 28 Comments

The PIXO Aspire is a roughly $35 USD vape that can almost play DOOM, with [Aaron Christophel] finding that the only thing that realistically stops it from doing so is that the Cortex-M4-based Puya PY32F403XC MCU only has 64 kB of SRAM. CPU-wise it would be more than capable, with a roomy 16 MB of external SPI Flash and a 323×173 pixel LC touch screen display covering the other needs. It even has a vibration motor to give you some force feedback. Interestingly, this vape has a Bluetooth Low-Energy chip built-in, but this does not seem to be used by the original Aspire firmware.

What [Aaron] did to still get some DOOM vapors on the device was to implement a screenshare firmware, allowing a PC to use the device as a secondary display via its USB interface. This way you can use the regular PC mouse and keyboard inputs to play DOOM, while squinting at the small screen.

Although not as completely overpowered as a recent Anker charging station that [Aaron] played DOOM on, we fully expect vapes in a few years to be perfectly usable for some casual gaming, with this potentially even becoming an original manufacturer’s function, if it isn’t already.

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A black, rectangular box is shown, with a number of waterproof screw connectors on the front.

A Ruggedized Raspberry Pi For Sailors

September 20, 2025 by 33 Comments

Nautical navigation has a long history of innovation, from the compass and chronometer to today’s computer-driven autopilot systems. That said, the poor compatibility of electronics with saltwater has consequently created a need for rugged, waterproof computers, a category to which [Matti Airas] of Hat Labs has contributed with the open-source HALPI2.

Powered by the Raspberry Pi Compute Module 5, the electronics are housed in a heavy duty enclosure made of aluminium, which also serves as a heat sink, and closes with a waterproof seal. It has a wide variety of external connectors, all likewise waterproofed: power, HDMI, NMEA 2000 and NMEA 0183, Ethernet, two USB 3.0 ports, and an external WiFi or Bluetooth antenna. The external ports are plugged into the carrier board by short extension cables, and there are even more ports on the carrier board, including two HDMI connectors, two MIPI connectors, four USB ports, and a full GPIO header. The case has plugs to install additional PG7 or SP13 waterproof connectors, so if the existing external connectors aren’t enough, you can add your own.

Besides physical ruggedness, the design is also resistant to electrical damage. It can run on power in the 10-32 volt range, and is protected by a fuse. A supercapacitor bank preserves operation during a power glitch, and if the outage lasts for more than five seconds, can keep the system powered for 30-60 seconds while the operating system shuts down safely. The HALPI2 can also accept power over NMEA 2000, in which case it has the option to limit current draw to 0.9 amps.

The design was originally created to handle navigation, data logging, and other boating tasks, so it’s been configured for and tested with OpenPlotter. Its potential uses are broader than that, however, and it’s also been tested with Raspberry Pi OS for more general projects. Reading through its website, the most striking thing is how thoroughly this is documented: the site describes everything from the LED status indicators to the screws that close the housing – even a template for drilling mounting holes.

Given the quality of this project, it probably won’t surprise you to hear this isn’t [Matti]’s first piece of nautical electronics, having previously made Sailor HATs for the ESP32 and the Raspberry Pi.