Can A CPAP Fan Become A Ventilator?

March 18, 2020 by 137 Comments

Watching the hardware community respond to the global pandemic is a fascinating process, because of the breadth of projects being considered, and also because of the differing experiences and perspectives being brought to the table. Components most of us might have been unaware of are appearing, such as the CPAP blower used by [Jcl5m1] in his ventilator design.

He starts with a very necessary disclaimer against trusting a random person on the Internet on the subject of medical equipment design, and since it must be possible to do damage with an inappropriate ventilator we can only echo that. But as a CPAP user he’s familiar with their operation and parts, and he’s taken the centrifugal blower from one of them and paired it with a speed controller and an Arduino to provide an adjustable pressure.

What we take away from this is not in any way a ventilator that’s ready to be hooked up to sick patients, but an interesting look at ventilators in general, CPAP components, and the possibility that this project and others like it might eventually form the basis of something more useful if they attract the attention of people with more experience in the field. We’ve already seen 3D-printing used to make valves for a respirator at a hospital in Italy.

Hearing Plants Giggle Is Just As Creepy As You Think

March 18, 2020 by 13 Comments

While best known for Charlie and the Chocolate Factory, Roald Dahl wrote quite a few similarly oddball stories in his time. One of them, The Sound Machine, is about a device that allowed the user to hear the anguished screams of trees as they were cut down. Sounds kind of weird to us, but [Roni Bandini] liked the idea so much he decided to build his own version.

Now to be fair, the device doesn’t only scream in pain. In fact, most of the time it should be emitting laughs and happy noises. Using a moisture sensor driven into the soil of a plant’s pot, the device uses these audio cues to tell you the relative health of your leafy friend. So assuming you’ve got any sort of green thumb at all, things should be fine.

But once the soil gets too dry and the device determines the plant is in “pain”, things take a turn for the worse. We suppose it doesn’t technically scream out so much as grunt like a zombie, but it’s still not a noise we’d want to hear while walking through the house at night. Luckily, it seems you need to hit the button on the front of the 3D printed enclosure to get it to play the appropriate sound track from its DFPlayer module.

Personally we’d rather build something that makes sure the plants are being taken care of automatically than a gadget that cries out in anguish to remind us that we don’t know what we’re doing. But hey, everyone gets inspired in their own way.

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This Is Not An Argument Bot

March 17, 2020 by 41 Comments

While in-person arguments are getting harder to come by these days, we’ll always have the internet (hopefully). So what can you do to stay on your game in a time when a little levity is lauded? Build an argument bot and battle wits with the best — a stern-faced John Cleese!

This latest offering from [8 Bits And A Byte] refers to a Monty Python sketch featuring an argument service — an office with a receptionist who will take your money and send you down the hall for a healthy and heated discussion. If you’ve never gone on a Monty Python binge, well, it’s probably as good a time as any.

Electronics-wise, the argument bot is a pretty simple build. A Raspberry Pi B+ outfitted with a Google AIY hat listens to your side of things and decides which bones to pick. Your obviously misguided statements are then matched with DialogFlow intents, and dissent is sent back through the speaker. Meanwhile, Mr. Cleese’s jaw moves up and down on a printed and servo-driven linear actuator while he maintains a stiff upper lip. Before you go off on that Python binge, check out the build video after the break.

Have you seen what can happen two robots argue? ‘Tis but a scratch. Continue reading “This Is Not An Argument Bot” →

Open-Source ARM Development Simplified

March 17, 2020 by 12 Comments

The ARM series of processors are an industry standard of sorts for a vast array of applications. Virtually anything requiring good power or heat management, or any embedded system which needs more computing power than an 8-bit microcontroller is a place where an ARM is likely found. While they do appear in various personal computers and laptops, [Pieter] felt that their documentation for embedded processors wasn’t quite as straightforward as it could be and created this development board which will hopefully help newbies to ARM learn the environment more easily.

Called the PX-HER0, it’s an ARM development board with an STM32 at its core and a small screen built in. The real work went in to the documentation for this board, though. Since it’s supposed to be a way to become more proficient in the platform, [Pieter] has gone to great lengths to make sure that all the hardware, software, and documentation are easily accessible. It also comes with the Command Line Interpreter (CLI) App which allows a user to operate the device in a Unix-like environment. The Arduino IDE is also available for use with some PX-HER0-specific examples.

[Pieter] has been around before, too. The CLI is based on work he did previously which gave an Arduino a Unix-like shell as well. Moving that to the STM32 is a useful tool to have for this board, and as a bonus everything is open source and available on his site including the hardware schematics and code.

3.2 GHz Vector Signal Generator Tear Down

March 17, 2020 by 15 Comments

[The Signal Path] snagged a fancy Rohde & Schwarz vector signal generator that can go up to 3.2 GHz, but sadly it wasn’t in working order. It powered up and even put out a 1 GHz signal, but the amplitude output was very wrong. Interestingly relative changes to the output were correct, it was just that the absolute output amplitude was off by quite a bit and changed with frequency. That started a detective job which you can follow along in the video below.

The instrument is pretty high-end, and did not report any problems even during self-check. This implied that all the internals were probably good and whatever was wrong probably lay close to the output. The service manual’s block diagram wasn’t terribly useful, especially given that all the processing portions appear to work well.

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A Smart Controller For Your DIY UV Cure Box

March 17, 2020 by No comments

Resin 3D printers are finally cheap enough that peons like us can finally buy them without skipping too many meals, and what means we’re starting to see more and more of them in the hands of hackers. But to get good results you’ll also want a machine to cure the prints with UV light; an added expense compared to more traditional FDM printers. Of course you could always build one yourself to try and save some money.

An earlier prototype build of the interface.

To that end, [sjm4306] is working on a very impressive controller for all your homebrew UV curing needs. The device is designed to work with cheap UV strip lights that can easily be sourced online, and all you need to bring to the table is a suitable enclosure to install them in. Here he’s using a metal paint can with a lid to keep from burning his eyes out, but we imagine the good readers of Hackaday could come up with something slightly more substantial while still taking the necessary precautions to not cook the only set of eyes you’ll ever have.

Of course, the enclosure isn’t what this project is really about. The focus here is on a general purpose controller, and it looks like [sjm4306] has really gone the extra mile with this one. Using a common OLED display module, the controller provides a very concise and professional graphical user interface for setting parameters such as light intensity and cure time. While the part is cooking, there’s even a nice little progress bar which makes it easy to see how much time is left even if you’re across the room.

At this point we’ve seen a number of hacked together UV cure boxes, but many of them skip the controller and just run the lights full time. That’s fine for a quick and dirty build, but we think a controller like this one could help turn a simple hack into a proper tool.

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Used Soda Stream Cylinder Becomes DIY Canned Air

March 17, 2020 by 16 Comments

Soda Stream machines use a cylinder of compressed CO2 to carbonate beverages, and cylinders that are “empty” for the machine’s purposes in fact still have a small amount of gas left in them. User [Graldur] shared a clever design for using up those last gasps from a cylinder by turning it into a makeshift compressed air gun, the kind that can blow crumbs or dust out of inconvenient spots like the inside of a keyboard. It’s 3D printed in PETG with a single seal printed in Ninjaflex.

[Graldur]’s 3D printed assembly screws onto the top of an “empty” cylinder and when the bottom ring is depressed like a trigger, the valve is opened slightly and the escaping gas is diverted through a narrow hole in the front. As a result, it can be used just as you would a can of compressed air. The gas outlet even accommodates the narrow plastic tubes from WD-40 cans (or disposable compressed air cans, for that matter) if more precision is required.

The design is intended for use with nearly-empty cylinders, but even so, [Graldur] also points out that it has been designed such that it can never fully actuate the cylinder’s release valve no matter how hard one presses, so don’t modify things carelessly. We also notice the design keeps the user’s hand and fingers well away from the business end of things.

This device also reminds of somewhat of a past experiment which used 3D printing to create serviceable (albeit low pressure) 3D printed compressed air tanks in custom shapes.