Author: Bob Baddeley

93 Articles

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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DNA Now Stands For Data And Knowledge Accumulation

February 18, 2020 by 33 Comments

Technology frequently looks at nature to make improvements in efficiency, and we may be nearing a new breakthrough in copying how nature stores data. Maybe some day your thumb drive will be your actual thumb. The entire works of Shakespeare could be stored in an infinite number of monkeys. DNA could become a data storage mechanism! With all the sensationalism surrounding this frontier, it seems like a dose of reality is in order.

The Potential for Greatness

The human genome, with 3 billion base pairs can store up to 750MB of data. In reality every cell has two sets of chromosomes, so nearly every human cell has 1.5GB of data shoved inside. You could pack 165 billion cells into the volume of a microSD card, which equates to 165 exobytes, and that’s if you keep all the overhead of the rest of the cell and not just the DNA. That’s without any kind of optimizing for data storage, too.

This kind of data density is far beyond our current digital storage capabilities. Storing nearly infinite data onto extremely small cells could change everything. Beyond the volume, there’s also the promise of longevity and replication, maintaining a permanent record that can’t get lost and is easily transferred (like medical records), and even an element of subterfuge or data transportation, as well as the ability to design self-replicating machines whose purpose is to disseminate information broadly.

So, where is the state of the art in DNA data storage? There’s plenty of promise, but does it actually work?

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New Year Habits – What Do You Do For Data Storage?

January 20, 2020 by 109 Comments

2020 is a year of reflection and avoiding regret, and one of the biggest practices we all know we should do better is back up our data. Inevitably there will be a corruption or accident, and we mourn the loss of some valuable data and vow to never let it happen again, and then promptly forget about good data retention practices.

I believe life is about acquiring memories, so it makes sense to me to try to archive and store those memories so that I can reflect on them later, but data storage and management is a huge pain. There’s got to be a better way (cue black and white video of clumsy person throwing up arms in disgust).

Nice Cloud You Have There; Shame if Something Happened to It

The teens of the century saw a huge shift towards cloud storage. The advantages of instantly backing up files and using the cloud as the primary storage for all your devices is appealing. It’s now easier to transfer files via the cloud than with a cable. With Google Docs and WordPress we have our most important documents and writing stored as database blobs on someone else’s servers. Facebook and Google and Flickr record all of our memories as photo albums. Unlimited storage is common, and indexing is so good that we can find photos with a vague description of their contents.

These things are instantly accessible, but lack permanence. Gone are newspaper clippings and printed photos discovered in a shoebox. When we aren’t in control of those services, they can disappear without any warning. Even some big offerings have packed up shop, leaving people scrambling to back up data before the servers were shut down. Google Plus is closed, Yahoo  Groups is closed, MySpace lost all content created prior to 2016, GeoCities closed in 2009, and Ubuntu One closed in 2014. It’s safe to say that no online content is safe from deletion. It’s also safe to say that cloud storage is a difficult location from which to extract your data.

With the risk of data leaks and privacy violations occurring daily, it’s also safe to say that some of your files should probably not be stored in the cloud in the first place. So, how do we do it well, and how do we get in the habit of doing it regularly?

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Parallel Pis For Production Programming; Cutting Minutes And Dollars Off Of Assembly

December 30, 2019 by 36 Comments

Assembly lines for electronics products are complicated beasts, often composed of many custom tools and fixtures. Typically a microcontroller must be programmed with firmware, and the circuit board tested before assembly into the enclosure, followed by functional testing afterwards before putting it in a box. These test platforms can be very expensive, easily into the tens of thousands of dollars. Instead, this project uses a set of 12 Raspberry Pi Zero Ws in parallel to program, test, and configure up to 12 units at once before moving on to the next stage in assembly.

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Conductive Tape Current Capacity Comparison

December 9, 2019 by 13 Comments

The world of DIY circuits for STEM and wearables has a few options for conductors. Wire with Dupont connectors is a standard, as is adhesive copper tape. There’s also conductive nylon/steel thread or ribbon. Which you choose depends on your application, of course, but as a general rule wire is cheap and ubiquitous while making connections is more challenging; copper tape is cheap and simple to use, but delicate and rips easily, so is best used for flat surfaces that won’t see a lot of stress or temporary applications; and conductive nylon thread or tape is better for weaving into fabrics.

The Brown Dog Gadgets team wanted to respond to a frequent question they are asked, what are the current limits for their Maker Tape (nylon/steel ribbon), so they ran some experiments to find out. In the name of Science you’ll see some flames in the video below, but only under extreme conditions.
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Optical Keyboards Have Us Examining Typing At Light Speed-ish

November 18, 2019 by 86 Comments

There’s a newish development in the world of keyboards; the optical switch. It’s been around for a couple years in desktop keyboards, and recently became available on a laptop keyboard as well. These are not replacements for your standard $7 keyboard with rubber membrane switches intended for puttering around on your raspberry pi. Their goal is the gamer market.

The question, though, is are these the equivalent of Monster Cables for audiophiles: overpriced status symbols? Betteridge would be proud; the short answer is that no, there is a legitimate advantage, and for certain types of use, it makes a lot of sense.

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pierced puffed exposed leads lithium ion battery

Lessons In Li-Ion Safety

November 13, 2019 by 85 Comments

If you came here from an internet search because your battery just blew up and you don’t know how to put out the fire, then use a regular fire extinguisher if it’s plugged in to an outlet, or a fire extinguisher or water if it is not plugged in. Get out if there is a lot of smoke. For everyone else, keep reading.

I recently developed a product that used three 18650 cells. This battery pack had its own overvoltage, undervoltage, and overcurrent protection circuitry. On top of that my design incorporated a PTC fuse, and on top of that I had a current sensing circuit monitored by the microcontroller that controlled the board. When it comes to Li-Ion batteries, you don’t want to mess around. They pack a lot of energy, and if something goes wrong, they can experience thermal runaway, which is another word for blowing up and spreading fire and toxic gasses all over. So how do you take care of them, and what do you do when things go poorly?

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