May 13, 2008 first day of the spring show was yesterday; i haven’t really posted much here in a while as i’ve been really busy trying to get things together for finals, and then finishing up fLUX (my LED staff for performance; more info on the project will be forthcoming).
if you’re in new york, stop by and check it out at ITP @ 721 broadway (at waverly)
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March 31, 2008 informal tests with Blackberry show much improved response (i’m actually a bit surprised; i would have expected the Blackberry to be engineered to eliminate as much background noise as possible). Sounds lasting over about 1/2 second from what i could tell though were attenuated quite a bit. tests with 250ms per 100 hz step actually came out quite good, even with me speaking over the sound, and regardless of direction phone was facing (though signal was a little stronger of course when the phone was facing the speaker).
For this test, i was sitting about 12 feet away from the speaker, about 5 ft below the speaker, with a shelf blocking part of the line of sight. Similar tests with LG8100 phone show a signal which *may* be strong enough to use, though very weak — using spectrum plot in Audacity is still able to pull the frequencies out from the background, by 10-20dB (not as good by far as i would like… blackberry is more like 30+ dB… though it looks like there is some LF stuff that needs to be filtered off)
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March 31, 2008 Initial tests with LG8100 cell phone (my old skool phone), recording to WAVs on an Asterisk server. Purpose is to roughly determine usable frequencies via cellphone. Older references on POTS system indicate usable range is 300hz - 3khz;
System uses XP100 card, echo cancellation enabled, no TX/RX gain, 5 seconds of pure (well, relatively pure anyhow) sine wave at each frequency, 100 hz steps. Recordings using standard voicemail feature.
100 hz: Audio “completely filtered” (no audible signal)
200 hz: signal is degraded but can be heard
300-abt 3000 hz: signal is clean for abt. .25 s (guessed) each step immediately after pitch change then a bit degraded
abt 3100-3300 hz: signal is degraded but can be heard
3400 hz: “completely filtered” (no audible signal)
Note: phone placed directly in front of speaker. Audio meter indicates levels at the different frequencies at this distance to range from 82 dB to 93 dB, mean 86, median 88, mode 89.
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March 12, 2008 I have this affliction. it seems that it’s impossible to remember when replying to messages on several school lists that replies by default go to the list, not just to the person who sent the original message. so i’ve essentially ended up inviting the whole list to my place for the weekend, sent “i’m interested; tell me more about the job” responses to everyone on the list, etc… and all of this despite 15+ years of active email list use.
I think the fault lies with pine, the email client i used for years. pine has an option, which i always had enabled, that would cause pine to ask if you wanted to use the reply-to address or to reply to the sender, when the two addresses didn’t match. it did this right when you hit “reply”, and it became something that i would automatically give the correct answer to. it was apparently too easy in this respect, and i never learned the hazards of a too-quick response to someone on an email list.
Now, after having made several mistakes in the past few days i finally decided to give up on trying to teach myself to automatically reply the right way. i’ve implemented a new technological crutch to lean on… actually i’ve just tweaked someone else’s code to do what i want, since it was easier to use code James Eagan wrote an Apple Mail plugin (and very helpful docs) that handled much of the basic Mail interface I needed.
If you wish to build the filter from source (optional):
Download the source. Unzip — it will create the directory StupidFilter. Read the README & COPYING files (it’s GPL, just like the plugin on which it is based) if you wish. Run “python setup.py py2app -A”. This will create a dist directory with the plugin.
To install (from source build or if you just download the plugin):
If you just downloaded the plugin, unzip it.
From the command line:
mkdir ~/Library/Mail/Bundles
Change into the directory the plugin is in (where you just unzipped it, or from source, the dist directory)
cp -r StupidFilterPlugin.mailbundle ~/Library/Mail/Bundles/
Now enable mail plugins:
defaults write com.apple.mail EnableBundles -bool true
defaults write com.apple.mail BundleCompatibilityVersion 3
Configure the addresses you want to be warned against writing to (in my case, the school email lists) by creating a new plain text file in your Library/Mail directory, named StupidFilterAddresses. If you wish, you can do this one address at a time by using
echo “some@email.address” >> ~/Library/Mail/StupidFilterAddresses
Restart Apple Mail for the plugin to take effect.
Test by adding an extra address to the list & write a test email to that address; confirm that a dialog pops up to confirm that you really want to write to that address.
Download the plugin
Download the source
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March 10, 2008 So after doing a bit of digging around on BEAM robots, the swirlies visualization, etc. i started playing around more with the whole electronic neuron thing. since then i’ve been playing with a number of different configurations, pretty much all logic gates with RC circuit inputs.
One of my favorite at this point is a configuration that will take in either pulses or a steady voltage and output pulses
--->|---+--+---|>o----+---
| | |
--- +->|--/\/\-+
.18uf --- 10k
|
gnd
note that’s a diode on the input and a diode and resistor across the inverter, and a .18uf capacitor from the input of the gate to ground.
with a voltage just above the trigger voltage of the gate (+ .6v for the diode’s drop) you can get very slow pulses… with higher voltages you get frequencies well in the audio range. And with tweaks to the R & C you can tailor chains to do different things; to pass pulses along a path, to require multiple neurons to connect to a single one (add another cap on each to isolate them), etc. these are a bit more complicated than the Nv neurons which require only the resistor and capacitor, but also have a new kind of behavior… and it’ll work as a basic VCO.
You can also replace the resistor & second diode with an LED, which changes behavior a bit (different LEDs have different voltage drops, and will discharge the capacitor to different levels when the gate output goes low).
still trying to get straight how i want to incorporate this all into my living art piece; i’ve got some audio oscillators going as well, and can trigger them just fine with this stuff… but i’m not so much into the whole “noise” scene, so a lot of the aesthetic is lost on me & i’m having trouble getting excited about what i’m able to get out of this stuff.
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