a1k0n

8 ms·

31.
by a1k0n 8y ago
I think just adding a simple low-pass filter on your distance measurements and tracking the derivative for PD control would cure that problem. Try it!
32.
by a1k0n 8y ago
Didn't mention it in the post, but info about the car hardware and all the code is at https://github.com/a1k0n/cycloid
33.
Fast line-following robots(a1k0n.net)
207 points by a1k0n 8y ago|26 comments
34.
by a1k0n 8y ago
Hats off for making use of the AAA instruction. That's a very clever sequence converting up/down/left/right to -320/+320/-1/+1.
35.
by a1k0n 8y ago
FWIW the main AMBE patent expired in December, but I was always surprised hams chose to use it.
36.
by a1k0n 9y ago
The landing page doesn't really explain what is interesting about Harvey. What does it mean that it's distributed, exactly?
37.
by a1k0n 9y ago
Would be nice if there was a "symmetric matrix" variable type, so it could simplify Ax + A'x to 2Ax if A is symmetric.
38.
by a1k0n 9y ago
I also wanted to nitpick this part of the article -- the neural network isn't determining the audio features; these are all hand-engineered features developed by The Echo Nest. The neural network is trained to mimic collaborative filte
39.
by a1k0n 9y ago
Don't forget the red box, which you could make by replacing the 3.579545 MHz crystal powering the chip that the OP reverse engineered with a 6.5536MHz one, and then the top row and bottom column tones become 1700 / 2200Hz to simul
40.
by a1k0n 10y ago
standard rogue/nethack movement keys work: y/u/n/b go diagonally.
41.
by a1k0n 10y ago
If they wanted to use a geosynchronous satellite from the ISS, it would be occluded by the earth half of the time and the other half of the time they'd have to track it with a satellite dish over the course of the 45 minutes (out of ev
42.
by a1k0n 10y ago
The x86 example is particularly cute: xadd eax, edx loop -3 implements the Fibonacci series in two machine instructions (notice eax and edx have 514229, 832040 in them after you run the example, the 29th and 30th Fibonacci nu
43.
3D rendering on an Arduboy(a1k0n.net)
4 points by a1k0n 10y ago|0 comments
44.
by a1k0n 10y ago
Well, in your case you're using the webkit exponentialRampToValueAtTime or whatever it's called, so you could just recompute the envelope (it's an exponential sweep... actually it's sort of double-exponential, which is a
45.
by a1k0n 10y ago
oh right, you wrote the other 303 web app! I was kinda mad because you stole my thunder while I was working on this one. :)
46.
by a1k0n 10y ago
Some day, perhaps, but the code is MIT license and anyone is welcome to collaborate. (FWIW, @pcgregory turned my fasttracker 2 player into a full fledged tracker: https://wetracker.herokuapp.com/ ) I'm busy with other p
47.
by a1k0n 10y ago
Sounds like this: https://www.a1k0n.net/code/webkitsynth/ Basically, not at all like a 303 except in spirit
48.
by a1k0n 10y ago
Huh. I wrote this code back in 2000 or so. Didnt realize someone had ripped it. https://github.com/a1k0n/gsynth/blob/master/modules/tb303/tb... It doesn't sound very much like a real tb303
49.
by a1k0n 10y ago
Right. I thought it might be 5v tolerant on the RX pin but maybe not.. easy enough to just use a resistor and a diode to the 3.3v supply to level shift there, and the 3.3v TX should be fine for a 5v logic input.
50.
by a1k0n 10y ago
FWIW you probably don't need a USB serial port, or a RS232 converter at all; you could just pick the TTL serial signals off the commodore port and plug them into the TTL serial port on the Raspberry Pi 23- or 40-pin expansion slot (pin
51.
by a1k0n 10y ago
They're also impossible to keep in tune, sound wildly different with small changes in temperature, and have a really terrible signal to noise ratio.
52.
by a1k0n 10y ago
The resonance appears to decrease with cutoff frequency because of high pass filtering in the feedback loop of the 303 filter... Higher frequencies have more feedback and thus more resonance. The envmod knob also affects both the max and mi
53.
by a1k0n 10y ago
Yes. And the optimal policy is trivial given those inputs, as long as the aperture between pipes is larger than the "jump" height of the bird: if bird y + bird y velocity > bottom pipe y, jump. So finding that with a neural net
54.
by a1k0n 10y ago
Sure enough, this is new with Sierra. El Capitan doesn't support it. Finally! I was tired of Seil/Karabiner/whatever else constantly updating itself and changing its name, just so I could remap caps lock to escape.
55.
by a1k0n 10y ago
Escape isn't an option. Or at least it wasn't before... There's a third party tool called Karabiner which enables this.
56.
by a1k0n 10y ago
It's sort of a shame this is built around an Atmega chip as opposed to an ARM Cortex M0 like in the Teensy. I guess it doesn't need much horsepower for a 128x64 monochrome display, but it wouldn't have been much more expensiv
57.
by a1k0n 10y ago
A super easy way to see this is to type cat, and then type asdf and hit ^D. It immediately echoes back what you typed. Another ^D quits cat, because it gets a 0-byte read that time.
58.
by a1k0n 10y ago
You're right, there's no stripes on its face. I stand corrected. Sadly, that was my most upvoted comment in ~9.5 years on this site.
59.
by a1k0n 10y ago
That's a chipmunk, not a squirrel.
60.
When machine learning matters(erikbern.com)
2 points by a1k0n 10y ago|1 comments

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