Embedded environment monitoring.

Disclaimer: This post has lots of links to the Adafruit website.  There are no referral links, I received no consideration, I just buy parts from there and do cool things with them.

A couple of weeks months ago I did a writeup of a prototype environment monitoring device for my office built out of a Raspberry Pi Zero W and some off the shelf components.  In the time since I've found time here and there to work on the embedded version, which doesn't use a full computer system but a microcontroller with just enough functionality to drive a couple of …

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Simple environment monitoring with spare parts.

It's going on summer in the Bay Area, which means that it's warming up a bit both outside and inside (because air conditioning is Not A Thing out here).  That, coupled with the not inconsiderable research infrastructure I have at home has left me wondering and worrying about just how hot my office gets during the day while I'm working.  Now, I could just put a simple little thermometer on my shelf (and I did) but my concerns are a bit bigger than that.  What happens if my office temperature reaches a critical point and servers start melting down on …

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Experimenting with btrfs in production.

EDIT - 20201206 @ 2216 UTC-7 - Added how to remove a hard drive and replace it with a bigger one to upgrade.

EDIT - 20200311 @ 1859 UTC-7 - Added how to replace a dead hard drive in a btrfs pool.

EDIT - 20191104 @ 2057 UTC-7 - Figured out how long it takes to scrub 40TB of disk space.  Also did a couple of experiments with rebalancing btrfs and monitored how long it took.

A couple of weeks ago while working on Leandra I started feeling more and more dissatisfied with how I had her storage array set up.  I had a bunch of 4TB hard drives …

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Linux on the Dell XPS 15 Touch (9570)

UPDATED: 18 March 2019 - External display adapters that actually work with this model (and Arch Linux) added.

For various reasons, I found that I had a need to upgrade Windbringer's hardware very recently.  This might be the first time that a catastrophic failure of some kind was not involved, so it's kind of a weird feeling to have two laptops side by side, one in process and one to do research as snags cropped up.  This time around I bought a Dell XPS 15 Touch (9570) - I was expecting things to be substantially the same, but this did not seem …

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Neologism: The Magick Poke

The Magick Poke - noun - When you touch a failing appliance, light bulb, or other gizmo in the just the right way as you're replacing it, and it spontaneously starts working again.  This usually saves it from the trashcan or dumpster.  Comes from the POKE command in Commodore BASIC which could let you do some pretty strange things by putting just the right value into just the right memory location, usually by fat-fingering a value.

A telephonic mystery.

If you've known me for any length of time, chances are you've heard about my fascination with telephones and some of the weird stuff that you sometimes find if you misdial once in a while. Sweep tones, ringbacks, ANACs, and more unusual things. However, it's rare that some of those weird things happen to ring me up.

A couple of weeks ago I started getting phone calls at all hours of the day; not terribly unusual in itself, save that every time I pick up I hear a prompt to leave a voicemail ("Press one to leave a voicemail.") Ordinarily …

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Deep learning gone wild, direct neural interface techniques, and hardware acceleration of neural networks.

There is a graphic novel that is near and dear to my hearts by Warren Ellis called Planetary, the tagline of which is "It's a strange world. Let's keep it that way." This first article immediately made me go back and reread that graphic novel...

The field of deep learning has been around for just a short period of time insofar as computer science is concerned. To put it in a nutshell deep learning systems are software systems which attempt to model highly complex datasets in abstract ways using multiple layers of other machine learning and nonlinear processing algorithms stacked …

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Linux on the Dell XPS 15 (9530)

Midway through December of 2014 Windbringer suffered a catastrophic hardware failure following several months of what I've come to term the Dell Death Spiral (nontrivial CPU overheating even while in single user mode, flaky wireless, USB3 ports fail, USB2 ports fail, complete system collapse). Consequently I was in a bit of a scramble to get new hardware, and after researching my options (as much as I love my Inspiron at work they don't let you finance purchases) I spec'd out a brand new Dell XPS 15.

Behind the cut I'll list Windbringer's new hardware specs and everything I did to …

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A friendly heads-up from work.

Windbringer experienced an unexpected and catastrophic hardware failure last night after months of limping along in weird ways (the classic Dell Death Spiral). My backups are good and I have a restoration plan, but until new hardware arrives my ability to communicate is extremely limited. Please be patient until I get set up again.