Ventilators 101: What They Do And How They Work

March 25, 2020 by 88 Comments

Treating the most serious cases of COVID-19 calls for the use of ventilators. We’ve all heard this, and also that there is a shortage of these devices. But there is not one single type of ventilator, and that type of machine is not the only option when it comes to assisted breathing being used in treatment. Information is power and having better grasp on this topic will help us all better understand the situation.

We recently wrote about a Facebook group focused on open source ventilators and other technology that could assist in the COVID-19 pandemic. There was an outpouring of support, and while the community is great when it comes to building things, it’s clear we all need more information about the problems doctors are currently dealing with, and how existing equipment was designed to address them.

It’s a long and complicated topic, though, so go get what’s left of your quarantine snacks and let’s dig in.

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Civilian RC Car Uses Lego NXT And Ada

March 14, 2020 by 4 Comments

Back in the last century, the US Department of Defense declared that Ada was going to be used everywhere and for everything. Books were published, schools build curriculum. Working programmers, however, filled out waivers to continue working in their languages of choice. As a result, only a little bit of safety-critical software really used Ada. However, we’ve noticed a bit of a resurgence lately. Case in point: an RC car using Ada for the brains. You can watch it tool around in the video below.

This isn’t the first time we’ve heard about Ada in the past few months. Partially, this could be because of the availability of the GNU compiler, although that’s been around since 1995, so maybe there’s another explanation. Ada’s strong typing does tend to plug holes that hackers exploit, so while we would hate to say it is hack proof, it certainly is hack resistant compared to many popular languages.

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Scott Shawcroft Is Programming Game Boys With CircuitPython

March 2, 2020 by 18 Comments

Some people like to do things the hard way. Maybe they drive a manual transmission, or they bust out the wire wrap tool instead of a soldering iron, or they code in assembly to stay close to the machine. Doing things the hard way certainly has its merits, and we are not here to argue about that. Scott Shawcroft — project lead for CircuitPython — on the other hand, makes a great case for doing things the easy way in his talk at the 2019 Hackaday Superconference.

In fact, he proved how easy it is right off the bat. There he stood at the podium, presenting in front of a room full of people, poised at an unfamiliar laptop with only the stock text editor. Yet with a single keystroke and a file save operation, Scott was able make the LEDs on his Adafruit Edge Badge — one of the other pieces of hackable hardware in the Supercon swag bag — go from off to battery-draining bright.

Code + Community

As Scott explains, CircuitPython prides itself on being equal parts code and community. In other words, it’s friendly and inviting all the way around. Developing in CircuitPython is easy because the entire environment — the code, toolchain, and the devices — are all extremely portable. Interacting with sensors and other doodads is easy because of the import and library mechanics Python is known for, both of which are growing within the CircuitPython ecosystem all the time.

CircuitPython is so friendly that it can even talk to old hardware relatively easily without devolving into a generational battle. To demonstrate this point, Scott whipped out an original Nintendo Game Boy and a custom cartridge, which he can use to play fun sounds via the Game Boy’s CPU.

Now You’re Playing With Python

It’s interesting to see the platforms on which Scott has used the power of CircuitPython. The Game Boy brings the hardware for sound and pixel generation along with some logic, but he says it’s the code on the cartridge that does the interesting stuff.

The CPU communicates with carts at a rate of 1MHz. As long as you can keep this rate up and the CPU understands your instructions, you can get it to do anything you want.

Scott’s custom cart has a 120MHz SAMD51. He spends a second explaining how he gets from Python libraries down to the wire that goes to the Game Boy’s brain — basically, the C code underneath CircuitPython accesses direct structs defined within the SAMD to do Direct Memory Access (DMA), which allows for jitter-free communication at 1MHz.

He’s using the chip’s lookup tables to generate a 1MHz signal out of clock, read, and A15 in order to send music-playing instructions to the sound register of the Game Boy’s CPU. It sounds like a lot of work, but CircuitPython helps to smooth over the dirty details, leaving behind a simpler interface.

If you want easy access to hardware no matter how new or nostalgic, the message is clear: snake your way in there with CircuitPython.

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Winners Of The Take Flight With Feather Contest

January 22, 2020 by 10 Comments

It’s hard to beat the fidelity and durability of printed text on paper. But the e-paper display gets pretty close, and if you couple it will great design and dependable features, you might just prefer an e-reader over a bookshelf full of paperbacks. What if the deal is sweetened by making it Open Hardware? The Open Book Project rises to that challenge and has just been named the winner of the Take Flight with Feather contest.

This e-reader will now find its way into the wild, with a small manufacturing run to be put into stock by Digi-Key who sponsored this contest. Let’s take a closer look at the Open Book, as well as the five other top entries.

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Inputs Of Interest: Tongues For Technology

January 21, 2020 by 23 Comments

Welcome to the first installment of Inputs of Interest. In this column, we’re going to take a look at various input devices and methods, discuss their merits, give their downsides a rundown, and pontificate about the possibilities they present for hackers. I’ll leave it open to the possibility of spotlighting one particular device (because I already have one in mind), but most often the column will focus on input concepts.

A mouth mouse can help you get your input issues licked. Via @merchusey on Unsplash

Some inputs are built for having fun. Some are ultra-specific shortcuts designed to do work. Others are assistive devices for people with low mobility. And many inputs blur the lines between these three ideas. This time on Inputs of Interest, we’re going to chew on the idea of oral inputs — those driven by the user’s tongue, teeth, or both.

Unless you’ve recently bitten it, burned it, or had it pierced, you probably don’t think much about your tongue. But the tongue is a strong, multi-muscled organ that rarely gets tired. It’s connected to the brain by a cranial nerve, and usually remains undamaged in people who are paralyzed from the neck down. This makes it a viable input-driving option for almost everyone, regardless of ability. And yet, tongues and mouths in general seem to be under-utilized as input appendages.

Ideally, any input device should be affordable and/or open source, regardless of the driving appendage. Whether the user is otherwise able-bodied or isn’t, there’s no reason the device shouldn’t be as useful and beautiful as possible.

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Teardown: BilBot Bluetooth Robot

January 20, 2020 by 16 Comments

Historically, the subject of our January teardown has been a piece of high-tech holiday lighting from the clearance rack; after all, they can usually be picked up for pocket change once the trucks full of Valentine’s Day merchandise start pulling up around the back of your local Big Box retailer. But this year, we’ve got something a little different.

Today we’re looking at the BilBot Bluetooth robot, which over the holidays was being sold at Five Below for (you guessed it) just $5 USD. These were clearly something the company hoped to sell a lot of, with stacks of the little two-wheeled bots in your choice of white and yellow livery right by the front door. With wireless control from your iOS or Android device, and intriguing features like voice command, I’d be willing to bet they managed to move quite a few of these at such a low price.

For folks like us, it can be hard to wrap our minds around a product like this. It must have a Bluetooth radio, some kind of motor controller, and of course the motors and gears themselves. Yet they can sell it for the price of a budget hamburger and still turn a profit. If you wanted to pick up barebones robotics platform, with just a couple gear motors and some wheels, it would cost more than that. The economies of scale are a hell of a thing.

Which made me wonder, could hackers take advantage of this ultra-cheap robot for our own purposes? It’s pretty much a given that the software for this robot will be terrible, and that whatever control electronics live inside it will be marginal at best. But what if we write those off and just look at the BilBot as a two-wheeled platform to carry our own electronics? It’s certainly worth $5 to find out.

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David Williams Is “FPGA-Curious”

December 6, 2019 by 17 Comments

If you hadn’t noticed, we had a bit of an FPGA theme running at this year’s Superconference. Why? Because the open-source FPGA toolchain is ripening, and because many of the problems that hackers (and academics) are tackling these days have become complex enough to warrant using them. A case in point: David Williams is a university professor who just wanted to build a quadruped robotics project. Each leg has a complex set of motors, motor drivers, sensors, and other feedback mechanisms. Centralizing all of this data put real strains on the robot’s network, and with so many devices the microcontrollers were running out of GPIOs. This lead him to become, in his words, “FPGA-curious”.

If you’re looking for a gentle introduction to the state of the art in open-source FPGAs, this is your talk. David covers everything, from a bird’s eye view of hardware description languages, through the entire Yosys-based open-source toolchain, and even through to embedding soft-CPUs into the FPGA fabric. And that’s just the first 18 minutes. (Slides for your enjoyment, and you can watch the talk embedded below the break.)
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