Strategy

What’s at the heart of the iRythm Zeo XT monitor?

Posted on by charlie

I came into possession of a Zeo XT long-term heart monitor (see image right). The device was sent to someone I know who ended up not using it. So I took it and, being curious, decided to crack it open and see what I could see.

The whole device was fascinating to explore and, without the benefit of knowing the designers, contemplate the design decisions.

Cracking it open
The is the cover. Note the blue dot. That’s a button I’ll show later on. [FYI, images follow explanatory text]

The cover opened up easily enough. Later, I realized it could be when the device is sent back, the technicians need to easily open it to access a micro USB port I’ll show shortly.

The bottom that the board sits on shows where the contacts for the leads come in, and you can see that there are divots for where the contact clips connect. There are also contact clips for the batteries. Smol. Smol.

That rectangle is the recess to accommodate the memory chip.

PCB
Lots of test points. View of both sides of the board. Closeups of some areas follow.

iRhythm Tech N100A6001.

Little clippy things for leads (in right image) and for batteries (in left image). 

That big chip is the ISSI IS34ML04G08. NAND memory. 

Closeups
Right next to the clips for the leads (next to two large resistors) is a chip with TI 86 I333. This chips seems to be an INA to convert voltages into data. 

Next to the memory chip, this chip says 263 8453 JSH. I wonder if it’s a NXP MMA8543 accelerometer. Not sure why there’s an accelerometer on this. If that’s what that chip is. I was just Googling things, not chasing it too deep.

The MCU is a ATSAM3U4C

The architecture is designed to sustain high-speed data transfers. The multi-layer bus matrix, multiple SRAM banks, PDC, and DMA support parallel tasks and maximize data throughput.

Seems like data downloading is thru USB (which MCU supports). I think that’s why it’s so easy to disassemble. 

And that’s a big blue button. The cover, shown earlier, flexes to click the button. This is the logging button that the user presses (when they feel an event?). Makes sense that it’s big and sturdy.

And here is an opamp.

I think these are power regulators. And I think all this is to clean up power noise?

Also, you can see the clips nearby for the batteries at the top (negative) and bottom left (positive). Tiny tiny clips.

Layers, donkey
Lastly, I wonder how many layers the PCB is. It’s about 1.5mm thick. But that’s not a good measure for number layers I presume. 

Yeah, I like investigating things like this.

The Narrative

Project: Bruins 100-year anniversary sign

Posted on by charlie

I had mentioned an earlier project where I hacked the parts of some solar deck lights, where the lights were cheaper than me buying all the parts myself.

So of course, when you have hammer, everything is a nail. So, of course, I have been thinking of other projects that can use the solar deck light parts.

One Hundred Years
The Boston Bruins are celebrating this year their 100th anniversary. Being a Bruins fan, I wanted to do something to celebrate, too.

So I figured I’d do a solar powered sign to put out front.

And, as I am a 3D printer kind of guy, I printed out the parts of the sign.

The build
I downloaded the current Bruins logo from WikiMedia and printed it out in three colors (see image above).

I then designed and built a frame to hold the logo and parts of the solar powered light, and to backlight the logo.

[Aside: because the print was so large, I did a lot of test prints of just certain parts, for example to ensure fit of battery and buttons and the like]
Designing in OnShape
Installing the electronics
All glued in (yay for hot glue)

In use
I was happy with the build. Only thing, I set it up high up on the side of my house (there was a hanging hook already there), where the eaves leave a shadow, even in January here at latitude 42°. Therefore, I was taking it down to charge in the full sun. I was also trying to hang it from a wire so that it was lower and more in the sun. But I did not like that.

As things progressed thru March, I gave up and just left it on the hook. Tho it is still in the shadow from the eaves, even longer as we head into Spring.

Also, because I had it and didn’t expect to use it much, I was doing my test prints in blue filament. In the end, I liked the color and kept it for the blue glow it provides behind the spoked B.

One other catch: The solar lights have three settings. The one I usually use is the third, which turns on the lights with movement.

But I wanted this sign to be on all the time. So I have it set to the second setting, where it is mostly lit and gets brighter with motion.

Luckily, anyone or anything passing in front of my house (many 10s of feet away) is picked up by the sensor.

Tho, being on all the time also means that the lights are not on all night. But the sign in the end is on for many hours after sunset when it starts with a full charge. Good enough for me!

And of course, folks can see the sign, albeit, small, during the day as well.

Go, Bruins!

Strategy/The Narrative

The Fediverse – and why I feel like Cassandra

Posted on by charlie

Been meaning to make this whine-post for some time.

Yes, I was excited with all the discussion last year of the fediverse, the rise of Mastadon (even tho it’s been around for while), the general growing realization of the enshittification of social media.

A new kind of social internet is currently forming. Right now it might still look like ‘Twitter and Reddit, only different,’ but that’s only the very beginning of what’s to come. Hopefully.

Source: Here’s why the fediverse is the future of social networks, and the web – The Verge

But I’ve been banging this drum for a while:

If those dates seem bunched up, it’s because around that time I was actually trying to build something (roughly 2006-2007) along the lines of taking control of the data streams of your life and others [My greatest story, never much told: Nokia Cloud]

And I’m not the only one who was thinking of these things. There were folks who contributed to the early days of the social, feedable, permalinkable, likable, tunable web back then who also were trying to federate things – knowing full well what would happen if big companies controlled things in silos.

Guess who won out?

Now all of us from back then feel like Cassandras, warning of a future no one believed but gladly accepted like so many frogs in warm water.

Sigh.

 

Image courtesy of DALL-E, who described the image as: “The image created captures the transition from a centralized and controlled social media landscape to a diverse and decentralized fediverse, reflecting the themes of angst and hope discussed in the article.”

The Narrative

Another time shift game – and my own take on it (story time!)

Posted on by charlie

This article (quoted below) reminded me of another similar iPhone game back in the day. I think it was some sort of space game. But same concept, each time you die, you come back and your previous lives repeat what you did. The idea is to use the repeats to do a task in concert.

Cool concept. And now there is another one, reviewed by the Verge.

You’re given an arena filled with enemies that you must defeat within a certain amount of time and a certain amount of chances. Once that time is up, you are teleported back to the beginning of the fight and forced to do it over again, this time with your “remnant” assisting you, killing the same enemies you killed in the previous loop.

Source: Fight monsters with the help of your past lives in Lysfanga: The Time Shift Warrior – The Verge

This recent article reminded me also how that other game had inspired me to write a short story within my NaNoWriMo novel back in 2012.

Check out the story here: Time and again

Enjoy.

Short stories/Snippets

Time and again (a short story)

Posted on by charlie

I woke just as soldiers entered the cabin and shot us where we lay. They left, and as the life seeped out of me the warship rammed us, the bow cleaving my boat with a resounding crunch that threw us across the cabin, water rushing in.

–x–

I woke up and got out of bed, quietly, so as not to wake her. I watched her. She had her back to me, as I put on my overalls. She was so beautiful and I could not get enough of looking at her curves, her shoulder, her hair.

I rushed on deck with two large explosives and threw them overboard. The dolphins would know what to do. I saw them snatch the explosives and disappear underwater. It was then, too late, to see that a dinghy approached. Shots were fired and two rounds hit me, burning through my arm and shoulder. I could do nothing as the soldiers came aboard and split up. One looked at me as I heard the shots ring out below. Then, he finished me off with a shot to the head.

–x–

I woke up and got out of bed, quietly, so as not to wake her. I watched her. She had her back to me, as I put on my overalls. She was so beautiful and I could not get enough of looking at her curves, her shoulder, her hair.

I scrambled on deck and saw the warship and dinghy approaching. I quickly hid. Then I saw me run on deck and throw the explosives overboard. The dolphins would know what to do. I watched me watch them snatch the explosives and disappear underwater. I then saw me look at the approaching dinghy. Shots were fired and I saw two rounds hit me, burning through my arm and shoulder.

Then, I jumped up when the soldiers boarded. I knocked a few off the deck with a wrench. But one managed to stab me in the gut and I fell. I could do nothing as the remaining soldiers came aboard and split up. One looked at me as I heard the shots ring out below and on deck. Then, he finished me off with a shot to the head.

–x–

I woke up and got out of bed, quietly, so as not to wake her. I watched her. She had her back to me, as I put on my overalls. She was so beautiful and I could not get enough of looking at her curves, her shoulder, her hair.

I watched myself wake up and quietly get out of bed, so as not to wake her. I watched as I watched her, she had her back to us, as I put on my overalls. She was so beautiful and we could not get enough of looking at her curves, her shoulder, her hair.

I and I scrambled on deck and saw the warship and dinghy approaching. I and I quickly hid. Then I watched me see me run on deck and throw the explosives overboard. The dolphins would know what to do. I watched me watch me watch them snatch the explosives and disappear underwater. I then saw me look at the approaching dinghy. Shots were fired and I saw two rounds hit me, burning through my arm and shoulder.

Then, I and I jumped up when the soldiers boarded. We knocked most of them off the deck with wrenches. But two managed to stab us in the gut and we fell. We could do nothing as the remaining soldiers came aboard and split up. One looked at me as I heard the shots ring out below and on deck. Then he finished me off with a shot to the head and then he finished me off with a shot to the head.

–x–

I woke up and got out of bed, quietly, so as not to wake her. I watched her. She had her back to me, as I put on my overalls. She was so beautiful and I could not get enough of looking at her curves, her shoulder, her hair.

I scrambled on deck and saw the warship and dinghy approaching. I saw that two of me were already hidden, waiting for the soldiers. I stated hauling on the main sail line. Then I watched me see me run on deck and throw the explosives overboard. The dolphins would know what to do. I watched me watch me watch them snatch the explosives and disappear underwater. I then saw me look at the approaching dinghy. Shots were fired. A round hit me in the chest, and I also saw two rounds hit me, burning through my arm and shoulder. I slowly crumpled to the deck.

Then, I watched me and me jump up when the soldiers boarded. I saw us knock most of them off the deck with wrenches. But two managed to stab us in the gut and we fell. We could do nothing as the remaining soldiers came aboard and split up. I watched as one looked at me as I heard the shots ring out below and on deck. Then I watched him finished me off with a shot to the head and then finish me off with a shot to the head and then walk over to finish me off with a shot to the head.

–x–

I woke up and got out of bed, quietly, so as not to wake her. I watched her. She had her back to me, as I put on my overalls. She was so beautiful and I could not get enough of looking at her curves, her shoulder, her hair.

I watched myself wake up and quietly get out of bed, so as not to wake her. I watched me watch me watch her. She had her back to us, as we put on my overalls. She was so beautiful and we could not get enough of looking at her curves, her shoulder, her hair.

I and I scrambled on deck and saw the warship and dinghy approaching. I saw myself see that two of me were already hidden, waiting for the soldiers. I saw myself start to haul on the main sail line, and then I started hauling as well. Then I watched me see me run on deck and throw the explosives overboard. The dolphins would know what to do. I watched me watch me watch me watch them snatch the explosives and disappear underwater. I then watched me see me look at the approaching dinghy. Shots were fired. I saw a round hit me in the chest, and I also saw two rounds hit me, burning through my arm and shoulder. I saw me slowly crumple to the deck, as I ran to grab the helm to catch some wind.

Then, I watched me and me jump up when the soldiers boarded. I saw us knock most of them off the deck with wrenches. But two managed to stab us in the gut and we fell. We could do nothing as the remaining soldiers came aboard and split up. I hollered at them and startling them for a moment, then swung the boat so that the boom would hit them.

Two ducked, but three were knocked over, though not enough because the boom was not loose enough. The two who ducked stood up and shot me down.

As best I could, I watched as one looked at me as I heard the shots ring out below and on deck. Then I watched him finish me off with a shot to the head and then finish me off with a shot to the head and then walk over to finish me off with a shot to the head and then walk over and finish me off with a shot to the head.

–x–

I woke up and got out of bed, quietly, so as not to wake her. I watched her. She had her back to me, as I put on my overalls. She was so beautiful and I could not get enough of looking at her curves, her shoulder, her hair.

I scrambled on deck and saw the warship and dinghy approaching. Shots were fired. I saw a round hit me in the chest, and I also saw two rounds hit me, burning through my arm and shoulder. I saw me slowly crumple to the deck, and saw me run to grab the helm to catch some wind.

Then, I watched me and me jump up when the soldiers boarded. I quickly grabbed the line the held the boom as I saw us knock most of the soldiers off the deck with wrenches. But two managed to stab us in the gut and we fell. We could do nothing as the remaining soldiers came aboard and split up. I then heard me holler at them, startling them for a moment, then I let go of the boom line as I swung the boat so that the boom would hit them.

Two ducked, but, with a horrible crack, the other three were knocked down. I watched as the two who ducked stood up and shot me down, then turned on me and shot me.

As best I could, I watched as one looked at me as I heard the shots ring out below and on deck. Then he finished me off with a shot to the head.

–x–

I woke up and got out of bed, quietly, so as not to wake her. I watched her. She had her back to me, as I put on my overalls. She was so beautiful and I could not get enough of looking at her curves, her shoulder, her hair.

I watched myself wake up and quietly got out of bed, so as not to wake her. I watched me watch me watch her. She had her back to us, as we put on my overalls. She was so beautiful and we could not get enough of looking at her curves, her shoulder, her hair.

I and I scrambled on deck and saw the warship and dinghy approaching. Shots were fired. I saw a round hit me in the chest, and I also saw two rounds hit me, burning through my arm and shoulder. I saw me slowly crumple to the deck, and saw me run to grab the helm to catch some wind.

Then, I watched me and me jump up when the soldiers boarded. I knew what I had to do and didn’t wait to watch me quickly grab the line the held the boom and watch us knock most of the soldiers off the deck with wrenches.

I scrambled up on top of the main cabin.

I knew that two managed to stab us in the gut and we fell. We were actually getting somewhere with the remaining soldiers who came aboard and split up. I held on as the boat pitched one way then the other. I then heard me holler at them, startling them for a moment, then let go of the boom line as I swung the boat so that the boom would hit them.

Two ducked, but, with a horrible crack, the other three were knocked down. I grabbed my rifle and watched as the two who ducked stood up and shot me down, then turned on me and shot me at the boom line.

As best I could, with two quick cracks of my rifle, I finished off one then the other with a shot to the head.
I looked up in time to see the warship explode and rapidly sink, the wake of its momentum and the explosion pushing my boat out of the way.

Exhausted, I went back below. She was so beautiful and I could not get enough of looking at her curves, her shoulder, her hair. I watched her. She had her back to me, as I removed my overalls. I got in bed, quietly, so as not to wake her, and fell asleep.

 

written in 2012 as part of a NaNoWriMo novel I wrote
image: courtesy DALL-E

The Narrative

OMG, what’s with stocks apps on mobile phones?

Posted on by charlie

My memories of the days when mobiles were starting to become a thing and everyone was snapping up some sort of PalmPilot or PDA, one prominent app that was offered on those PDAs and early phones (and RIM pager?) was stock price look-up app.

Back then, buying and trading stocks by normal plebes was getting to be a thing. Or at least, back in those heady days of the rise of Bay Area bros making millions off of IPOs and folks on TV and the internet flogging stocks, folks promoted stock trading as a thing.

But was stock tracking and trading so prevalent that _every_ mobile device needed an app? And back then, the apps were prominently promoted. [Tho, my memory of when they started showing up might be hazy, as I can’t seem to find any screenshots of such apps from those days. I sure feel that the prevalence of stock price apps bothered me all these years.]

<shakes head>

The iPhone still comes with a stocks price tracking app (see it also in the iPhone launch photo above). And now I read that they were even considering an investing feature.

Apple came close to creating an investing feature for the iPhone that would’ve let users buy and sell stocks directly on the device

from: Apple reportedly stopped short of bringing a stock trading feature to iPhone (The Verge)

In any case, is my grumpiness around this just because I don’t follow stock prices? Do you use the app regularly? Am I just the anomaly?

[and then I see this hand-made ESP32 powered a stock tracker 🙄]
Strategy

Make. Smaller. Cars.

Posted on by charlie

I think part of the reason Ford is having issues is that their EVs are or are going to be gigantic.

Ford’s been riding the trend of bigger and bigger trucks and SUVs such that they’ve built themselves out of sedans and smaller trucks that are probably better suited for EVs.

Indeed, I think the trend of the past few years of larger SUVs and trucks actually has given folks the wrong expectation of what cars should be as we enter the EV-era.

The car company says it isn’t backing off its next-gen EVs, but it is pausing some big factory projects, including a plant in Kentucky.

Source: Ford hits the brakes on $12 billion in EV spending because EVs are too expensive – The Verge

 

UPDATE: After I wrote this, other reasons to make trucks smaller: Truck bloat is killing us, new crash data reveals

Strategy/The Narrative

Did SEO experts ruin the internet or did Google? – The Verge

Posted on by charlie

Just wanted to say: this is a really good article.

The article is a great snapshot of where we are in SEO, with insights from the start many decades a go. Great quotes from interesting characters, too.

As the public begins to believe Google isn’t as useful anymore, what happens to the cottage industry of search engine optimization experts who struck content oil and smeared it all over the web? Well, they find a new way to get rich and keep the party going.

Source: Did SEO experts ruin the internet or did Google? – The Verge

Strategy

What do you think of Humane’s AI-powered wearable?

Posted on by charlie

It’s a gadget designed for interacting with large language models, not apps, and for talking instead of typing. But it’s not yet entirely clear what you’re supposed to use it for.

Source: Humane officially launches the AI Pin, its OpenAI-powered wearable – The Verge

I’m not so worried that this is a new kind of device, trying new forms of interaction and design. And kudos for being gutsy to use LLM so early in the evolution of the tools.

But already folks are pointing out LLM errors in the demo. And I’d like to point out in the launch video, Bethany, Humane’s woman co-founder, never speaks with the device [my experience with Siri and Amazon Echo showed that women have a heard time being understood by voice input tools, let alone those in the over-55 bracket]. And do we really want some device blaring out results in public, results that might be quite personal, instead of being respectfully silent and replying thru a headset?

Again, I welcome new devices that try new things and attempt to change our expectations of what our tools should do and how we should interact with them.

And I totally agree that we’ll really only see how useful this is after it’s out in the wild and being used.

But, will it go the way of smartwatches (well-received for many reasons) or the way of smartglasses (well-received in particular use cases, but by no means a consumer device)?

What do you think?

 

Ha, right after I wrote this I found this article (via Hackaday): The Humane AI Pin is a bizarre cross between Google Glass and a pager

Lots of good points, some echoing and elaborating on the same things I mention. Go read it.

The Narrative

Frak you, ChatGPT – good writing is still good writing

Posted on by charlie

Humans are really good at coming up with better ways to create things. And humans are also very good at pointing to anything new as the end of the world as they know it. And those folks are not far off their prediction, but not how they think.

Writing will make you styoopid
Did you know that Socrates was against writing? Writing wasn’t a newish thing in his day. Nonetheless, he didn’t think it was an effective way of communicating. And he worried that folks would become forgetful.

But writing has been central to humanity’s growth and dissemination of knowledge and in the sharing and enjoyment of stories. Can you imagine a world without writing? You would have to meet up with me for me to tell you what I’m writing here.

Derivative drivel
I’ve been following how folks have been reacting to generative AI for making images, text, music, and audio. The worried ones are concerned about copyright, plagiarism, thinking effort (familiar, eh, Socrates?), and such.

Yet, if you think of the process of writing, there’s extensive reading (indeed, the best writers are voracious readers), there’s the exercise of learning styles from existing sources, there are editors and proofreaders to help the best writers be better. And we know that plagiarism and ghost writing happens.

So what’s the fear with ChatGPT? The system is trained on a broad range of material – just like anyone who reads everything. The system synthesizes all of that into an output – just like anyone who writes. 

Indeed, the article quoted below from the NYT is one of the few very well-balanced explorations of the impact of generative AI, in this case, on college admission essays.

A.I. chatbots could facilitate plagiarism on college applications or democratize student access to writing help. Or maybe both.

Source: Ban or Embrace? Colleges Wrestle With A.I.-Generated Admissions Essays. – The New York Times

Good writing is always good writing
One thing that no one seems to point out in all the articles I have read: no matter WHO writes the text, krap writing is still krap writing.

In a previous post where I used ChatGPT for programming, I mentioned that ChatGPT is a krappy programmer, but was helpful to accelerate my programming tasks. In the end, I had to know how to program for ChatGPT to help me.

The same is for any writing: you need to be a good writer to turn the ChatGPT text into good text.

_____ will democratize ____
When blogs came out, folks said that anyone could become a journalist, everyone would be writing online and there would be an explosion of text online.

But in the end, the best blogs were written by writers and journalists.

When podcasts were reborn, folks said everyone would be able to create audio channels of all sorts. But the podcast that brought podcasts from the dead, Serial, was produced by a long-time radio crew. And all the best podcasts are made by professional audio teams.

Good writing and radio is made by folks who know how to create, do the effort, and produce good writing and radio. Generative AI will not displace them.

As one of the students mentioned in the NYT article says:

But she found the responses too broad and impersonal, even after she gave it details about her extracurricular activities like teaching dance classes to younger students.

“I feel a little more pressure to create, like, this super unique, interesting topic,” Ms. Vakharia said, “because a basic one these days could just be generated by ChatGPT.”

In short, she knows she still needs to put in the work to write a good essay.

Good writing will always be good writing.

 

Image from janeb13