a kind of micro-SD card that doesn't much exist
Saturday, October 3 2015
The morning was cool enough to justify an immediate fire, which was nice when, not long thereafter, we had our weekly coffee in the living room.
I gathered firewood in the same spot where I've been doing it of late, out on the edge of the terrace a couple hundred feet southeast of where the Chamomile crosses the Stick Trail. Today I added about 14 pounds of super-dry skeletonized White Pine to my usual load of Chestnut Oak, since it's always good to have a little of that in the mix, especially in the mornings when I don't want to fuck around too much to get a fire going. Later when I weighed the load, I was surprised to find it was just shy of 117 pounds. It had seemed a lot heavier. Had I not attached it misconfigured it on the frame? But then I found a piece I hadn't weighed, and it weighed 25 pounds, making the load an impressive 142 pounds, which is up there with the three or four heaviest firewood loads that I have ever carried.
The most difficult schlep on the walk home is always that mountain goat path leading from the Stick Trail's terrace up to the small terrace where the woodshed list. But I've been continually improving it almost every time I set off on it into the forest. These improvements are usually the placement of flat rocks in places where my footholds aren't ideal or at the bottom, where the trail crosses a very shallow gulch before beginning the ascent. Ideally, the slope would be a constant climb upward, as gentle as possible and with no turns. It's close to that now; it executes a gentle arc after leaving the Stick Trail and that gulch at the bottom is nearly filled in. I like the way it looks; it has that same all-organic-but-subly-altered-by-intelligent-organism look that I'm going for when I articulate a stick trail (such as the Stick Trail).
My problems with procrastination continued today, though an impasse with my clock project seemed likely to force me back to less recreational passtimes. I spent some time searching my MP3 collection and YouTube for various audio clips and then using Audacity to edit them down to short passages. One of these was the part of Led Zepplin's "Immigrant Song" where Robert Plant wails, "Aeeeyah...ahh!" like a terrifying Arab about to detonate his vest; it's a passage I have used before. Another was the spooky passage in L'ham de Foc's song "Àngels de Menta" where the vocalist sings, "Sinistra i dreta" ("left and right" in some form of Catalan). I also had a couple explosions, samples of Big Ben, and a muezzin's adhan. Ultimately, I wanted these clips to form a small library on a micro-SD card to be played by my homemade clock using a WTV020SD. I have a lot of micro-SD cards, but the WTV020SD is particular about the ones it can use; they must be two gigabytes or smaller. But since the micro-SD format arrived after the smallest forms of media had transitioned to 4 gigabytes and larger, two gigabyte micro-SD cards tend to be rare. I certainly don't have any, so I was forced to buy some on eBay (it won't be problem if the ones I bought prove fraudulently small, since I will only be using a tiny fraction of one). Not being able to load up a card with sound files that I could then play from a WTV020SD meant that I wasn't going to be making any progress on my clock project for the next several days.
I didn't realize that I had no 2 gigabyte micro-SD cards until after I'd already wired up the WTV020SD on a solderless breadboard. In the process of doing that, I learned that it was a strictly 3.3 volt device, meaning I was going to have to temper the logic levels coming from the Arduino Mega2560. Something I read about SD cards suggested that they are always 3.3 volt devices, a fact that I had never heard until today. We use SD cards all the time and never really think about what voltage they run at. I suppose I'd always assumed they were five volt devices, because they are routinely hooked up to USB adapters, and those run at five volts. I was horrified when I confirmed that SD cards really do require 3.3 volts; I'd been running my weatherstation client for months with a 4-gigabyte micro-SD card hooked up to five volt logic and powered at five volts. It had been working fine this way, but perhaps this was only because it was at the end of a fairly long (and thus voltage-dropping) USB cable. You'd think that the page on the Arduino website where SD card interfacing is discussed would prominently feature something about SD cards' voltage requirements, since most Arduino devices use five volt logic. But no, it's never mentioned once. Perhaps this is because they assume we'll be using Arduino-approved interface shields, which would handle the voltage translations automatically. For those of use using cheap Chinese hardware, well, screw us! (The Adafruit.com site's page about SD cards does stress these voltage realities, but today was the first time I encountered it.) I quickly changed the voltage supply for the weatherstation's micro-SD card to 3.3 volts, though I haven't done anything about the five volt logic up to which it is hooked. Now it's looking like I should just do all of the weatherstation's client electronics in 3.3 volts (since all of it will work at that level). And if I do that, it will open a nice migration path to a more powerful 32-bit microcontroller (such as the one used in the Teensy) should the demands of my graphics plotting overwhelm the abilities of the 8-bit Atmega2560. (All of those 32-bit Arduino boards run at 3.3 volts.)
Late tonight I was getting out of the bathtub when I heard Ramona come running down the stairs into the basement. She briefly went into Gretchen's library and then ran back up the stairs. I'd noticed that the library had started taking on a bit of gamey smell again, and Ramona's brevity in there suggested a possible explanation. Sure enough, when I went in there, I found a small wet spot on the remaining shag carpet. (By this point, Ramona was long gone, so I couldn't even yell at her.) As you'll remember, Gretchen had had me tear up half the carpet in that room because waves of cats have been using it as a litterbox. Evidently, Ramona had decided to maintain that tradition using the half that remained. Gretchen was not going to like that. But I didn't want to rip all that remaining carpet. If anything, I wanted to salvage what was there. So I dumped a bunch of water into the shag where Ramona had just pissed (and also into a number of nearby hot spots). Then I used the wet vac to suck up as much water as I could. Finally, I lifted up the carpet and the underlying foam and trained a fan on it, hoping it would dry out before the mold set in. Only then did I tell Gretchen (who was still awake in bed reading, even though it was nearly 2:00am). We discussed theories for why Ramona had done this. Was she too much of a princess to go out in the cold to piss now that it's chilly outside? Or is that carpet so compellingly lawnlike that Ramona considers it the same as grass? In any case, we've shut the door to Gretchen's library until we can figure out what to do next.
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