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Jason

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(no subject) [Dec. 31st, 2016|05:46 pm]
Jason
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A paper on describing circuits in an agda DSL: http://www.staff.science.uu.nl/~swier004/publications/2015-types-draft.pdf
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(no subject) [Dec. 30th, 2016|09:12 pm]
Jason
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Going more carefully now through this little tutorial on fpga programming with the iCEstick. It's in spanish, which makes it slightly more challenging, but also more fun.
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(no subject) [Dec. 29th, 2016|09:48 pm]
Jason
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Some further progress cleaning up the https://xkcd.com/1360/ -esque augean stables that is my hard drive.

Tomato chicken I made a couple days ago was initially bland, but had improved stewing in its own juices in the fridge.
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(no subject) [Dec. 28th, 2016|09:11 am]
Jason
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migraine or flu or something? Felt very headachey and basically napped the whole day way.
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(no subject) [Dec. 27th, 2016|06:38 pm]
Jason
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Did some personal archaeology. Helped a little with laundry. Threw some chicken, onions, tomato, stock, peppers in the slow cooker and hopefully shredded chicken and rice and beans dinner will come out of that.
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(no subject) [Dec. 26th, 2016|06:37 pm]
Jason
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Extremely unproductive sleepy day, which was therefore very fruitful as a vacation day.
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(no subject) [Dec. 23rd, 2016|10:17 am]
Jason
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Dinner with akiva and dannel at nuevo portal in carroll gardens. Ate a pile of chicken stew and rice and beans and maduros, good times. I do miss brooklyn a little, still. Hadn't seen dannel in forever, good to catch up.
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(no subject) [Dec. 22nd, 2016|06:23 pm]
Jason
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Achievement unlocked teaching myself things every ece freshman knows, part 938472 and a half: I grok Thevenin's theorem well enough to prove the R-2R ladder works for digital-to-analog conversion.

Reasoning about resistor networks as random walks actually helps quite a bit. Recall that the voltage in a resistor network (with some known voltage sources at the leaf nodes) at point P is equal to the expectation of taking a random walk (with the probability of taking a step across a resistance R being proportional to 1/R) and taking the known voltage of the first voltage source you hit.

So I can reason that
       R1          R0
V1 |---vvvv---O---vvvv ...
              |
V2 |---vvvv---+
       R2

is equivalent to
        R3         R0
V3 |---vvvv---O---vvvv ...

for V3 = (V1R2 + V2R1) / (R1 + R2) and R3 = R1 R2 / (R1 + R2) from considering what happens at point O in the random walk: having a probability of (1/R1)/((1/R1) + (1/R2) + (1/R0)) of ending the walk with value V1 and a probability of (1/R2)/((1/R1) + (1/R2) + (1/R0)) of ending the walk with value V2 is the same in expectation as replacing both those posibilities with a single one whose probability is their sum, and whose terminal value is the weighted average of their values, which comes out to being V3 with probability (1/R3) / ((1/R3) + (1/R0)).

that said, if I ever want to do a project with analog output, I'd probably just buy an Adafruit MCP4725 instead.

Oh, and I can play around with it interactively in this circuit simulator. Nice.
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(no subject) [Dec. 22nd, 2016|06:13 pm]
Jason
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Dinner at Aliada; hadn't been there in a while. Nice savory custard on the moussaka, nice pork kebab sandwich.
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(no subject) [Dec. 20th, 2016|09:49 pm]
Jason
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Guy from Seattle team we've been working with showed up today at work; no matter how much I'm generally comfortable working with remote teams (and I think at this point I am quite comfortable with it) it's always fun to hang out with people in person a bit once in a while.
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