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minimal grid
Monday, March 7 2011
Since adding the long extension to Solar Controller III's I2C bus in support of the fuel-level-sensing range finder, I've had difficulty with other parts of that bus, particularly communication with the slave Atmega, which provides half of the system's analog inputs. So today I decided to make it so that the long extension to the I2C bus only exists (in an electronic sense) when I need to check the level of the fuel oil (an infrequent need). One way to achieve this would have been to connect it via a relay that the master Atmega can throw or unthrow as necessary, but because the electrical signals were low voltage and low amperage, I chose a solid-state alternative: 4016 quad bilateral switches. These are the functional equivalent of tiny relays, and I've been aware of them since the early 1980s. I've never actually made much use of them, always having chosen opto-isolators or mechanical relays instead. But the application here was perfect for bilateral switches. It even made use of their bilaterality (which means current might need to flow in either direction through them, something a transistor or an opto-isolator does not permit). So I brought Solar Controller III up to the laboratory, removed it from its box, and added a new I2C board connector (salvaged analog CD audio connectors from an old PC motherboard), which I attached to the board's I2C bus through half of a quad bilateral switch. I controlled this switch using one of the master Atmega's pins. After some additions to and debugging of the controller's software, the new arrangement worked perfectly.
Tonight Gretchen and I would be joining others for buffet night at the Garden Café in Woodstock to celebrate our friend Deborah's birthday. Deborah loves art, so I decided to make her some as a present. For inspiration, I drew upon another of her loves: her dog Juneau. I also drew upon a recent passing interest of mine: very tiny icons. If you navigate to a mainstream website using most any browser, you'll see, just to the left of the URL in the address bar, a tiny icon representing that website. Such icons are only sixteen by sixteen pixels, and thus contain only 256 blobs of color. And yet they can usually convey the branded essence of a website. I found myself wondering if I could convincingly depict Juneau as a tiny sixteen by sixteen pixel icon. To find out, I went to Deborah's Facebook pictures, found an image containing Juneau, cropped it down to just his head, and then shrank it to only sixteen by sixteen pixels. I couldn't figure out how, in Photoshop, to then expand it to macroscopic while preserving the sharp distinction between the original pixels, but I was able to simply zoom in on the tiny 16 by 16 image. It was this view that I used as the model for a painting I made on a block of two by six that I'd cut down to exactly four inches on a side and then ruled into a 16 by 16 grid. From there, the process of painting was mostly a mechanical exercise of mixing acrylic paint to match the colors in a square and then painting them. I started slowly, but 256 is a lot of squares to cover precisely, so eventually I started doing them in simultaneous multiples when the colors were "close enough" in appearance to each other. Then I went back and tweaked some of the squares. I'd used only red, white, and black, but it looked a little dingy that way, so I came through and put yellow highlights on the lightest blocks. The result was a fairly convincing Juneau, but only when seen from across the room.
I've probably mentioned this before, but the great thing about a buffet is that one can graze and quickly find the most delicious items and just concentrate on eating those while avoiding the less-desirable items that are sure to find their way on your plate when ordering a specific thing from a printed menu. So tonight I ate unusually well at the Garden Café, focusing mostly on a red bean Jamaican soup and delicious balls of tempeh that had been slathered in vegan mayonaisse and then encrusted somehow with red onions. Gretchen had put together a gift pack for Deborah that included a "Teeny Weeny" battery-powered sex toy. Oddly, though, she'd spaced out and forgotten to bake Deborah a cake, something she usually does. Michæl from KMOCA was there, and he told us all about someone who had hacked into his Paypal account and had run up charges that he was having a difficult time contesting. (Paypal, being a robot-run corporation, is not especially known for its customer service.) But Deborah's friend Tammi (who was also there tonight) could top that. Some time ago someone started adding charges to her business account just small enough that she didn't notice. By the time she'd figured out what had happened, she was out 26 thousand dollars, and it was too late for the credit card company to do anything to help her (or so they told her).
For linking purposes this article's URL is:
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