Shallow Thoughts

Sewing Project: A Helmet Cover with Ear Flaps

With the weather getting cold, I need a way to keep my ears warm while biking.

Many years ago, I had some fleece earwarmers that velcroed around a helmet strap. I bought them in a bike store and they worked wonderfully, but I've been unable to find anything quite like them online. I've knitted triangular cozies to go over a helmet strap, but they don't stay up, so they sag and don't cover my ears.

I tried making something like that, but they didn't come out well,

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Tags: sewing, maker, bike, MTB
[ 12:58 Jan 21, 2026    More bike | permalink to this entry | ]

Visiting the Santa Fe Moon Tree

The Radiolab podcast (or actually, their "Terrestrials" spinoff for kids) recently had an episode about Moon Trees.

Stuart ‘Smokey’ Roosa went to the moon (well, at least to lunar orbit) in 1971 as the Command Module Pilot for Apollo 14. He was an ex-firefighter, ex-smoke jumper, and he loved trees. So for the small personal item that astronauts are allowed to carry on missions, he brought along a canister of 500 tree seeds of various types. After almost getting destroyed (listen to the episode for more detail on Stu and his seeds), the seeds ended up back on earth, where they were planted in a variety of locations, from the White House lawn to private yards.

And then ... everyone forgot about them for a while, until their rediscovery by a third grader (again, listen to the episode, it's a great story). More recently, Natalie Middleton wrote an article about Moon Trees, including a map of the currently known moon trees.

I checked the map to see if there were any in New Mexico. There's one in Silver City, a sycamore, and some day I'll get down there to visit — but wonder of wonders, there's also a Douglas fir Moon Tree in Santa Fe! It's at the Roundhouse (the state capitol). I had to go see it.

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Tags: astronomy, moon, travel, nature, moon trees
[ 14:45 Jan 10, 2026    More travel | permalink to this entry | ]

Best Books I Read in 2025

Happy New Year!

Time for an annual "Best Books of the Year" list. As always, these aren't all new books this year; they're just new to me. (Or even a beloved re-read, but this year I'm not listing any of those.)

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Tags: books
[ 12:34 Jan 01, 2026    More misc | permalink to this entry | ]

Making a Place Names Overlay in QGIS

Flipping through Craig Martin's old book

Los Alamos Place Names

, I noticed that in the maps at the beginning, he has a rough map of some of the topographic names for local canyons and mesas.

We were just talking about that on a hike last week — looking out at the canyons north of Rendija and trying to get the names straight. Most maps don't label canyons, mesas, or even watercourses, which is endlessly frustrating for hikers who like geography.

I wondered how hard it would be to make a place names layer in QGIS based on Craig's map (and, of course, other sources too) that I could export as an overlay for use in OsmAnd or PyTopo. And it's always good to learn a little more about how to use QGIS effectively.

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Tags: mapping, GIS, qgis
[ 14:28 Dec 30, 2025    More mapping | permalink to this entry | ]

A Homebuilt CO2 Meter as a Virus Risk Proxy

Despite most of the world deciding that COVID is over, I continue to be cautious about it. (My one bout of COVID resulted in congestive heart failure which I'm still dealing with, so I'm fairly anxious not to get it again.)

That means that I'm cautious about indoor gatherings. Some places say they've upgraded their ventilation, but can you believe them? I've long read about people using CO2 meters as a proxy, to tell you how well the air is circulating and how high the virus load might be in a crowd, and I've wanted to get one of my own.

You can buy CO2 meters, of course. But making a custom one sounds so much more fun! Reading Wired's story about New Zealand's Kawaiicon cybersecurity convention that provided CO2 trackers inspired me to finally order some parts.

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Tags: maker, hardware, python, circuitpython
[ 18:06 Dec 19, 2025    More hardware | permalink to this entry | ]

Crimping JST PH Connectors

(With a cheap imperfect tool)

I've written about the several neat boards I recently ordered from Adafruit.

But when I ordered, I was confused about which connectors were which, and didn't end up ordering all the connectors I needed.

Adafruit calls the connectors they use "Stemma", and (I realized too late) they have a helpful page called What is Stemma? explaining the different connectors. I had ordered several of the small ones, "Stemma QT", more technically a 4 Pin JST SH, which were perfect for connecting a Feather board to a CO2 meter. But I hadn't realized that the bigger board, the PyPortal, needs a larger connector also called Stemma, more technically a JST PH.

It turned out to be hard to find JST PH connectors with wires already attached ("pigtails") and what I found were impressively expensive in lots of two or three. I imagine I might want a fair number of JST PH, especially the 2-connector type used for batteries. So I ordered a boxed assortment of 2, 3 and 4-pin JST PH connectors and a crimp tool.

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Tags: hardware, maker, electronics
[ 13:34 Dec 14, 2025    More hardware | permalink to this entry | ]

Installing CircuitPython on a Gemma M0

(On Linux.)

I wrote previously about my difficulties installing CircuitPython on an ESP32 Feather.

When I ordered the Feather, I ordered a bunch of other stuff too, including a tiny wearable microcontroller that's sold specifically for MicroPython: a Gemma M0.

Again, I had trouble getting MicroPython working, but the Gemma's problem was quite different.

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Tags: hardware, python, circuitpython
[ 18:13 Dec 09, 2025    More hardware | permalink to this entry | ]

Installing CircuitPython on an ESP32 Reverse Feather TFT

(On Linux, natch.)

I've been wanting to play around with CircuitPython for ages. I like Python, I like microcontrollers, what's not to like? Quite a while back, I even ordered a Feather M0 for that — but I didn't do my research, ordered the wi-fi version and it turned out that's the one Feather M0 that can't run CircuitPython.

This time I checked more carefully before ordering, and got a processor that for sure claimed to run CircuitPython.

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Tags: hardware, python, circuitpython, maker
[ 13:58 Dec 04, 2025    More hardware | permalink to this entry | ]