I played my junky old Sorento guitar through my Fender Prosonic on the dirty channel with a heavy dose of amp reverb, and stuck an sm57 about a foot away through one of the Octopre preamps, and used the Fat Head II on the other side of the room, pointing at the amp, and ran that through my Seventh Circle Audio A12 preamp.  So we have a close/room mix.  For the record, there is a slight EQ on the fathead tracks, mostly just a rumble (read: Heating Noise) reducer:

I forgot this was on them until I bounced out most of the tracks, so tuff luck- there’s EQ on them.

First up is a section where I’m playing a crappy guitar solo.  I have no chops.  I have clips of the 57 alone, FH alone, mixed, and then in the context of the song.  Remember the placement is VERY different on the mics.

sm57 Solo

Fat Head Solo Guitar

57 + FH Solo Guitar

In Context 57 + FH Guitar Solo

Then I’ve got the same thing for a crunchy section.

SM57 Crunch Guitar

FHII Crunch Guitar

57 + FH Crunch

In Context 57 + FH Crunch Guitar

I really like the mic.  I’m gonna try to build some portable cheap acoustic panels out of rigid fiberglass insulation to improve the room sound somewhat…  I am also planning on swapping out the stock transformers for some luhndals.  They sell them this way on their website, but I can order them and do the mod myself for less money.  And I’m going to mess around with my Little Labs IBP plugin for my UA card to see if that makes the mics play any nicer together, but even as is- with minimal fuss, I think the combination of 57 + ribbon adds a nice beefiness to the texture.

I also cut some demo vocals with the thing, and they sound pretty neat too.  If I determine the clips are suitable (read: minimally embarrassing), I’ll have some clips of that as well.

My favorite part is that the apparent justification for such an apparently obvious conclusion is “what are u talking about?”  And this is the best answer, deserving of thanks.

Well, if that doesn’t just revive your hope for the future of mankind, I don’t know what will.

It sounds pretty good too, but it’s a little hummy – which I think is probably the breadboard.  A very simple circuit, but has a couple options for modding.  There’s a low-pass switch you can throw, and you can swap out the capacitor for different amounts of low-pass.  And you can mess with the kinds of diodes you use, and whatnot.  Fun project, with a Russian name, so I’m going to have fun painting this one.

Most of the trouble with this project was hacking through the various electronics components grab bags I bought to find the right parts.  The numbering schemes on the caps in particular are tricky.  I got a few that I think are caps, but I’m still not sure.  And how do I tell what kind a random diode is?  If I ever find out, I’ll let you know.

It’s a combination of show-offy pictures of food, recipes, discussion about cooking techniques, and food/diet/culture talk.  Sustainability and being healthy and all that hippie crap.

It’s a separate blog, so you want to follow it, you should subscribe to the Foodblog RSS feed in addition to this one.

This was my workspace on 2-5-2010. Click for a humongous version (1.9mb).

Items of note:

• Ohm’s Law
• Medicine Man balsa wood glider (half finished)
• Make:Electronics book, Maker’s Notebook
• Woolly Mammoth clone guitar pedal, nearly done
• 2.5 gallon fishtank, testing out temperature logging via LM34 and Arduino (see FishApp) for more details.
• There are no less than five computers on/around my desk. Not all are visible.
• Small cheap telescope
• Printing plate of some old ship
• Guitars.
• More guitars.

The mess?  Oh, that just means I’m getting work done.

So much for science, and how helpful it can be in these times of environmental calamities. Chernobyl is still hotter than a Hiroshima baby carriage. Our underarm deoderants have eaten holes in the ozone layer.
And just get a load of this: My big brother Bernie, who can’t draw for sour apples, and who at his most objectionable used to say he didn’t like paintings because they didn’t do anything, just hung there year after year, has this summer become an artist!
I shit you not! This Ph.D. physical chemist from MIT is now the poor man’s Jackson Pollock! He squoozles glurp of various colors and consistencies between two flat sheets of impermiable materials, such as windowpanes or bathroom tiles. The pulls them apart, et voila! This has nothing to do with his cancer. He didn’t know he had it yet, and the malignancy was in his lungs and not in his brain in any case. He was just farting around one day, a semi-retired old geezer without a wife to ask him what in the name of God he thought he was doing, et voila! Better late than never, that’s all I can say.
So he sent me some black-and-white Xeroxes of his squiggle miniatures, mostly dendritic forms, maybe trees or shrubs, maybe mushrooms o umbrellas full of holes, but really quite interesting. Like my ballroom dancing, they were acceptable. He has since sent me multicolored originals, which I like a lot.

The message he sent me along with the Xeroxes, though, wasn’t about unexpected happiness. It was an unreconstructed technocrat’s challenge to the artsy-fartsy, of which I was a prime exemplar. “Is this art or not?” he asked. He couldn’t have put that question so jeeringly fifty years ago, of course, before the founding of the first wholly American school of painting, Abstract Expressionism, and the deification in particular of Jack the Dripper, Jackson Pollock, who also couldn’t draw for sour apples.
Bernie said, too, that a very interesting scientific phenomenon was involved, having to do, he left me to guess, with how different glurps behave when squoozled this way and that, with nowhere to go but up or down or sideways. If the artsy-fartsy world had no use for his pictures, he seemed to imply, his pictures could still point the way to better lubricants or suntan lotions, or who knows what? The all-new Preparation-H!
He would not sign his pictures, he said, or admit publicly that he had made them, or describe how they were made. He plainly expected puffed-up critics to sweat bullets and excrete sizable chunks of masonry when trying to answer his cunningly innocent question: “Art or not?”

I was pleased to reply with an epistle which was frankly vengeful, since he and Father had screwed me out of a liberal arts college education: “Dear Brother: This is almost like telling you about the birds and the bees,” I began. “There are many good people who are beneficially stimulated by some, but not all, manmade arrangements of colors and shapes on flat surfaces, essentially nonsense.
“You yourself are gratified by some music, arrangements of noises, and again essentially nonsense. If I were to kick a bucket down the cellar stairs, and then say to you that the racket I had made was philosophically on par with The Magin Flute, this would not be the beginning of a long and upsetting debate. An utterly satisfactory and complete response on your part would be, ‘I like what Mozart did, and I hate what the bucket did.’
“Contemplating a purpoted work of art is a social activity. Either you have a rewarding time, or your don’t. You don’t have to say why afterward. You don’t have to say anything.
“You are a justly revered experimentalist, dear brother. If you really want to know whether your pictures are, as you say, ‘art or not,’ you must display them in a public place somewhere, and see if strangers like to look at them. That is the way the game is played. Let me know what happens.”

I went on: “People capable of liking some paintings or prints or whatever can rarely do so without knowing something about the artist. Again, the situation is social rather than scientific. Any work of art is half of a conversation between two human beings, and it helps a lot to know who is talking at you. Does he or she have a reputation for seriousness, for religiosity, for suffering, for concupiscence, for rebellion, for sincerity, for jokes?
“There are virtually no respected paintings made by persons about whom we know zilch. We can even surmise quite a bit about the lives of whoever did the paintings in the caverns underneath Lascaux, France.
“I dare to suggest that no picture can attract serious attention without a particular sort of human being attached to it in the viewer’s mind. If you are unwilling to claim credit for your pictures, and to say why you hoped others might find them worth examining, there goes the ball game.
“Pictures are famous for their humanness, and no for their pictureness.”

I went on: “There is also the matter of craftsmanship. Real picture-lovers like to play along, so to speak, to look closely at the surfaces, to see how the illusion was created. If you are unwilling to say how you made your pictures, there goes the ball game a second time.
“Good luck, and love as always,” I wrote. And I signed my name.

(From Vonnegut’s 1997 novel “Timequake,” which I kinda liked, even though it was kindof all over the place, because it occasionally contained some really good stuff like this. Please don’t sue me, owners of Vonnegut’s rights. Just trying to make conversation.)

This little bit does a fairly tidy job of responding to the volumes of stuff that has been written trying to pin down really specific definitions of what this crazy thing called art is. Coming from a technical background (with a little artistic goodness thrown in), my inclination was to try to come up with a really nice reductive definition of art (of course ignoring the social conversation going on). But good ol’ Kurt does a good job of making sense, as always.

Merry Christmas, from me and my robots.

You tell ‘em, McGoohan.

To refresh your memory, the FishApp keeps track of water changes, and gives you a graph showing weighted-age values for the water in your fish tank.  This requires you to pay attention while you’re doing the water change, and to log in to the website and report how much water you changed when.  Well, I want to have the FishApp sense, measure, and publish water changes for me.  To those ends, I designed a system that can measure the water level in the tank over time, report it to a computer, figure out when and how much water was changed, and report that back to the main fishapp web application.  The measurement is done using a Ping))) ultrasonic rangefinder, and data from that (and other sensors) is fed into a computer.

But just how is the computer supposed to figure out when a water change happened?  It’s input is just a string of numbers, and it’s gotta be smart enough to filter out random noise from tank cleanings, frisky fish, the water filter starting and stopping for one reason or another, or any of a hundred other situations.  What to do?

If you’ve read the last post about the FishApp, you know where to start – smooth out the data.  To recap, I have the sensor set to read the water level every half-second, and report it to the computer.  The raw data is pretty noisy:

but if we make new data points from the median of  every 20 samples, things smooth out pretty quickly:

The system should be able to handle this muuuch easier.

The algorithm works by keeping a queue of recent (smoothed) samples.  By comparing the oldest sample with the newest sample, you can get a “slope” value.   On the graph above, for example, it doesn’t take very many samples until the oldest will be just over 600 but the most recent will be around 800 or so, and you’ll have a large positive slope.  Once the algorithm sees this large positive slope (above a certain trigger value), it knows that a water change is beginning, and notes the water level beforehand.  At some point in the process of a water change, I start filing the tank up again, and we see a large negative slope (around 55-60 on the graph above).  The algorithm notes the capitulation and the minimum water level.  If the absolute value of the slope stays low enough for long enough, the algorithm detects a steady state, and calls it the end of the water change.  The “steps” you see on the graph are because I do my water changes bucket-by-bucket, but because the algorithm is using a slope from a queue maybe 10 samples long, it already does a pretty good job of smoothing these steps out, and not getting too confused.

After running the algorithm against the data above, it worked flawlessly.  Take a look at this graph:

The gray lines are where the important steps in the process were detected.  For example, the first gray line @ x=10 is where the algorithm first noticed we were emptying water out of the tank.  It looks late – and it is, but that’s merely a consequence of using a queue of 10 samples to generate the slope.  The actual “before” water level value it uses is not the one at the gray line, but the minimum one in the queue – which is correct (enough for rock and roll).  Then, at x=54, the algorithm detected a large negative slope and decided that we were filling the tank up again.  It started looking for the start of a steady state, which it found at x=121, and it stayed steady long enough that at x=150, the algorithm wrapped up and decided that we’ve done a water change.  NIFTY!

If you think about what is going on here, it’s really calculus, under the covers.  The slope value is the derivative of the function, and we look for the points that derivative changes sign.  But the function we’re using isn’t perfect, and isn’t continuous, and so we’ve got to build in a little extra wonkitude-resistance.  The algorithm has inputs for the size of the queue, the trigger value for large positive/negative slopes, a tolerance value to ignore noise during steady states, and the number of samples to go during a steady state before deciding we’re really done with the water change – so in theory, this algorithm could be adapted and tuned for a wide range of input sources with little-to-no modification.

Right now, the algorithm is coded in python, but I think it might even be possible to do the crunching on the Arduino.  If I did that and wired the Arduino up to an ethernet shield, I could ALMOST eliminate the computer altogether.  I still need the computer to run the webcam, however, so there’s no point in trying to run this code on the chip or anything like that.  But I think it would be possible in theory, if you don’t want the cam server running.

The watch is a  Seiko affectionately called the “Orange Monster.”  It’s a huge, loud, fun, heavy watch – and it makes me quite happy.  I also made and put up a giant X-Files “I Want To Believe” poster.  There are several different images for this poster floating around on the net, and much to my chagrin, it turns out it’s NOT the one that I see behind Mulder’s desk in the series.  Ah, well.