Fixing NRF24L01+ Modules Without Going (Too) Insane

Good old nRF24L01+ wireless modules are inexpensive and effective. Well, they are as long as they work correctly, anyway. The devices themselves are mature and well-understood, but that doesn’t mean bad batches from suppliers can’t cause hair-pulling problems straight from the factory.

[nekromant] recently got a whole batch of units that simply refused to perform as they should, but not because they were counterfeits. The problem was that the antenna and PCB design had been “optimized” by the supplier to the point where the devices simply couldn’t work properly. Fortunately, [nekromant] leveraged an understanding of the problem into a way to fix them without going insane in the process. The test setup is shown in the image above, and the process is explained below. Continue reading “Fixing NRF24L01+ Modules Without Going (Too) Insane”

Game Boy Replica Built In Brass

Nintendo’s Game Boy is legendary for being the meat in the handheld gaming revolution, as well as being nigh-on indestructible whether in the custody of children or soldiers in the Gulf War. However, [Jiri] decided to see if he could whip up a tribute of his own, in brass instead of plastic.

The hardware is based on the Odroid GO emulator firmware for the ESP32, running on a 2.2″ color TFT screen. It’s a great base for a custom build, which avoids gutting any precious classic hardware. It’s then assembled behind front plate milled out of brass, with delicate point-to-point brass wires giving it an artistic circuit sculpture look. The brass did prove difficult to work with at times, acting as a heat sink which prevented easy soldering of the standoffs in place. To get around this, [Jiri] used a hotplate to heat the plate from below, keeping it warm enough so that a hand iron could do the job.

The final result is a fun Game Boy emulator in a stylish case – though one you shouldn’t throw in a back pack lest it short out the exposed conductors. It would make a great gift for any lifelong Nintendo fan. [Jiri] is no strange to circuit sculpture, as we well know – we’ve featured his tools and methods before. Video after the break.

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The US Air Force Wants Your 3D Scanner Ideas

One key piece of technology from Star Trek is the replicator, a machine that 3D prints up almost anything using some hazily-defined high technology. You have to wonder though, how did the patterns for Earl Grey tea or a spare part for a shuttlecraft intercooler come to exist in the first place. Maybe someone designed them, or perhaps they scanned the real articles. The US Air Force is betting on the latter, and they’ve asked for white papers and proposals for innovative methods to scan objects for 3D printing.

It isn’t surprising military planners would like to have effective 3D printing. After all, you can’t carry every spare part you might need into a theater of operation. Not to mention spares for your friends in joint operations or for enemy gear you might happen to capture. Having a truck that could turn out whatever your troops need is an attractive proposition. Continue reading “The US Air Force Wants Your 3D Scanner Ideas”

Keeping An Eye On The Water Heater Pilot Light

[WJCarpenter]’s gas water heater uses a small pilot light that needs to stay burning permanently to ignite the main burners as required. Four or five times a year, the pilot light goes out and needs to be manually lit. This involves an expedition from the upstairs bathroom to the basement, always in the early morning, after having spent a few fruitless minutes waiting for hot water. Having grown tired of this exercise, [WJCarpenter] built Water Watcher, a pilot light monitoring system with some ESPs and a light sensor.

Water Watcher consists of an ESP8266 connected to a light sensor taped to the inspection window of the water heater. It reports the status of the pilot light over MQTT to an ESP32-based M5 Atom Matrix in the main bedroom, which displays it using a 5×5 RGB matrix, as demonstrated after the break. Both ESPs run ESPHome, so programming is as easy as giving it a YAML config file. [WJCarpenter] tested a few different light sensors, until he found the TSL2591, which is sensitive to the right wavelengths and has enough dynamic range for watching a pilot light.

This might not be a complicated hack, but we do not doubt that it reduces frustration a bit on those fateful mornings. Be sure to check out the Water Watcher project page, it’s an entertaining read! Continue reading “Keeping An Eye On The Water Heater Pilot Light”

Making Silicone Molds – Big Ones!

If you’ve got one of something and you want more, duplicating it with a silicone mold can be a great way to go. This is applicable to 3D printing something you need many copies of, and a whole variety of other usecases. [Eric Strebel] prides himself on his abilities in this area, and has put out a guide to producing very large silicone molds in a simple and reliable manner.

The overarching process is simple, but followed properly, it produces great results. [Eric] starts by building a mold box out of wood, coated in shellac to ensure it doesn’t stick to the silicone. The master part is then stuck to the base, surrounded by a lasercut cardboard strip which acts as a seal and key. Once properly degassed silicone is poured in and cured, the second half can be made. The mold is flipped in the mold box, the seal key removed,  and release agent applied to the silicone surfaces. With another pour and cure, the mold is ready for casting new parts.

While simple, if the correct equipment isn’t used or steps skipped, you’ll end up with a useless mold full of air bubbles or surface irregularities. It’s useful to see just what it takes to get a mold of such scale (13″ x 19″!) completed without flaws. We’ve featured [Eric]’s work before, such as his fine detail improvements on the Apple Pencil. Video after the break.

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Inflatable Hospital Isolation Wards

The continued spread of Covid-19 has resulted in a worldwide shortage of hospital beds. A temporary hospital isolation ward (translated) was co-developed by the Korea Advanced Institute of Science and Technology (KAIST) and the Korea Institute of Radiological and Medical Sciences (KIRAMS) to help alleviate this problem. We’re not familiar with the logistics and expense of installing traditional temporary hospital facilities, but the figures provided for this inflatable building approach to the problem seem impressive. It takes 14 days to produce one module, a process which presumably could be pipelined. Being 70% lighter and smaller than their rigidly-constructed counterparts, they can be more easily stored and shipped where needed, even by air.

Once on-site, it takes one day to inflate and outfit it with utilities such as electricity, water, and communications. One of these modules, which look like really big inflatable Quonset huts, contains an intensive care unit, four negative-pressure rooms, a nursing station, staff area, changing and bathrooms, and storage. All this in a 450 m2 building 30 m long and 15 m wide. That works out to be almost 2-stories tall, which is confirmed by the photo above.

Now that the design is finished and a functional unit constructed, the goal is to put it into production as soon as possible. Of course, physical hospital facilities are not the only thing in short supply these days — doctors, nursing and support staff, medical supplies, not to mention the vaccinations themselves, are all needed. But hopefully the success of this project can contribute to the global effort of saving lives and getting control of the virus sooner rather than later. The video below is in Korean, but the automatic English subtitles aren’t too bad.

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A Few Of My Favorite Things: Amateur Radio

Hackaday has among its staff a significant number of writers who also hold amateur radio licenses. We’re hardware folks at heart, so we like our radios homebrew, and we’re never happier than when we’re working at high frequencies.

Amateur radio is a multi-faceted hobby, there’s just so much that’s incredibly interesting about it. It’s a shame then that as a community we sometimes get bogged down with negativity when debating the minutia. So today let’s talk about a few of my favourite things about the hobby of amateur radio. I hope that you’ll find them interesting and entertaining, and in turn share your own favorite things in the comments below.

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