atomic_fungus (atomic_fungus) wrote,

#5131: Apparently today is World Water day.



You know, at work they have a chart in the lunchroom which delineates every single "awareness" day and the ribbon color associated with it. Even things like colorectal and bladder cancer have "awareness" days now, and guess what their ribbon colors are?

Brown and yellow, respectively.

This "consciousness raising" shit drives me buggy. You know? And it always has, from the time I first encountered it as a single-digit-age lad. The thing with the ribbons is pure horseshit, always has been. WTF.

* * *

So, a bunch of muslim savages did it again, this time in Belgium. You let them into your country, sooner or later this is what will happen.

* * *

Even with gas prices lower than they've been in a long time, there is still a market for the Elio. People like me who want a new car but won't (and/or can't) pay the whopping huge loan required for one. A new car under seven grand? Perfect for commuting? Sure, it doesn't have a fancy 4G LTE internet hotspot, GPS navigation, and an iPhone dock, but none of that stuff is necessary. The auto industry has added a literal five hundred pounds' worth of gewgaws to the average car, making something that was already prohibitively expensive much more so.

The other day I saw a tiny Chevy subcompact, smaller even than the Aveo; it's the Chevrolet Spark, and it starts at $13,000 and rapidly climbs towards the stratosphere. I'm not kidding about the "tiny" part; it looks about as big as a Smart with a back seat.

Top price is eighteen grand, which is more than I paid for my 1993 Thunderbird (the most expensive car I ever bought).

The auto market, as it stands now, is unsustainable.

* * *

Today it's ridiculously nice outside, but I slept in, as I've been planning to do all week. Today, I promised myself, I would do nothing except maybe take a trip to the grocery store for a few sundries. I'm not going to fix anything, I'm not going to build anything, I'm not going to clean anything; I am just going to relax. Probably I will cook dinner (I am thinking about trying to replicate the chicken dish I made the other day) but otherwise I am going to relax.

I'm going to attempt the same tomorrow, though less aggressively.

Looking over some schematics on the Intartubzors I'm thinking the 555 timer may not do what I need it to, in order to build that "you left the stove on again moron" alarm. My initial perusal doesn't show any way for the thing to leave an output off until a set time has elapsed, after which that output remains on until reset. I'm going to have to breadboard the circuit and fiddle around with it to make sure. If I can add a couple of 7400-series logic chips and make it do what needs doing, that's fine; I have a bunch of that stuff laying around, too. A latch or a flip-flop or something would probably be sufficient, and it's just a matter of figuring out how to make the circuit do what I want.

One of the advantages of using a logic circuit is the fact that many of them are designed to change states on the edges of a square wave. A square wave is just what it implies, a voltage that goes from zero to five volts (and vice versa) in an arbitrarily short period of time. The transitions are known as edges, and you can have a positive-going edge (where the voltage is rising) or a negative-going edge (where it's dropping). Particularly when it comes to clocked logic, they typically change states on the negative going edges of the clock signal.

(Clocked logic: any kind of chip which has a clock input, so that it can be synchronized with a system clock signal. Latches, flip-flops, and counters work this way, among other things. Like, for example, about 99% of the chips in your computer.)

I figure that I could set up the 555 as a timer, then wire its output to the clock input of a flip-flop. The 555 stays on for a set time (1.5 hours, which will work fine, by the way) and then, when that period expires, the negative-going edge of the timer signal triggers the flip-flop's clock, the output of the flip-flop goes high, and presto--there's your alarm. Press the reset button to shut it off. Maybe have an AND gate in there, to check that the state of the "cooktop on" light is lit when that timer signal goes low again, so that if the cooktop light is off and the timer expires I don't get spurious alarms. (Using that light both as an "output enable" line as well as the trigger for starting the whole works. Heh. Clever.)

...and I begin to understand why so many people go right to microcontrollers. I bet if I were to use the Arduino for this I could implement the whole thing with three or four lines of code...but that would be like using a machine gun to hunt squirrels. It's overkill; and I dislike using a $30 dev board when a handful of ICs I already have will do splendidly.

* * *

Well, now I'm done with another blog post; and now it's on to aggressively relaxing and recreating.

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