November 2009 - chuck-users - lists.cs.princeton.edu

Chout flush
by Hans Aberg 24 Nov '09

24 Nov '09

Is there a way to flush chout (and cherr) other than sending "\n"? Hans

3 5

eChucK Update
by Les Hall 24 Nov '09

24 Nov '09

Hi, you may recall that I wrote some time ago about this eChucK project that I dreamed up. It had some fits and stumbles at first, but now the concept is evolving into actual products. The first board didn't really work out for various reasons so I basically took a $130 hit and cut my losses, giving three boards out for free to people who might make use of them. Oh well, you win some you lose some. The second board is extremely simple. It is a little postage-stamp sized breakout board designed to hold one chip plus discreet parts and solid wire interconnect. We can make sound sculptures by connecting these populated boards with the wire and arranging them in 3D. I had 100 boards made for $225 and sold 42 of them so far for $2.50 each, a modest 10% markup due to it being a prototype and all that. I have ordered parts to build two types of sculptures: Chiphenge and Tie Fighter. Next on the horizon is a Karplus Strong board implemented as an analog circuit. Just yesterday I completed the prototype in breadboard form and I cannot express how satisfying it was to listen to guitar and percussion sounds, and it even does a pretty good motor cycle / chain saw sound, heh. I spent most of Sunday afternoon broadcasting test audio of it on my internet radio port to friends, who really enjoyed the variety of sounds that it makes. Next up: order parts then complete the board design. Finally, I have a Boolean Sequencer board, a song timer board, and a clock / battery board planned to round out the selection of ChucK-inspired eChucK DIY products. It is a lot of fun to put my engineering knowledge to good use for a change. Oh, one more thing. There is now an eChucK forum sitting right next to the ChucK forum on www.electro-music.com, so stop by and have a read if you like. That's all for now. Keep on ChucKin'. Les

2 1

Exp2
by Hans Aberg 24 Nov '09

24 Nov '09

There seems to be no exp2 in 'chuck'. For time efficiency, I thought it might be better to use store intervals in natural base, using log and exp. But it turns out that C99 has both exp2 and log2 and the time difference (in C++) over using exp and log is insignificant; using pow(2, x) takes twice the time. So I think chuck should have both exp2 and log2, and they should call the C99 functions. Hans

1 0

ChucK meets eChucK
by Les Hall 22 Nov '09

22 Nov '09

ChucK and eChucK had a nice first date, though they did not hit it off right away. First ChucK was mumbling because his output volume was too low so he did not excite eChucK's input circuitry. Then things improved when ChucK invited eChucK to a livecoding session. With eChucK's CV PWM circuit not listiening, ChucK tried different stimulus input pulse widths until eChucK responded favorably with some percussion sounds. Then ChucK tried one of his favorite lines, "adc => dac;", and eChucK really lit up with renewed interest. Apparently you can send voice into the stim input of the Karplus Strong circuit and get a vocoding effect. At this point the date joke was getting old, so I invited some radio friends to tune in to my port and listen while I tweaked the circuit. As it stands right now I've somewhat lowered the noise with a carefully placed capacitor though it is still loud. The stim input can be a 10::ms pulse (bass drum) or a 10::ms noise burst (snare). The CV input circuit requires redesign. It's a problem because I'm trying to generate a DC level from an AC coupled output, which is a little bit tricky so I'm working on it. Overall the date went well. eChucK and ChucK had a good time and made beautiful if somewhat monotonous music together. I think they like each other. Les

1 0

chuck mirror
by Ge Wang 21 Nov '09

21 Nov '09

Greetings! It seems that primary ChucK site is down (along with a number of other Princeton CS sites). Here is the mirror at Stanford: http://chuck.stanford.edu/ Best, Ge! ~~~ Ge Wang Assistant Professor Center for Computer Research in Music and Acoustics (CCRMA) Stanford University http://ccrma.stanford.edu/~ge/ ~ Co-founder, CTO, Chief Creative Officer Smule http://www.smule.com/ | http://twitter.com/gewang ~~~

1 0

ChucK meets eChucK
by Les Hall 19 Nov '09

19 Nov '09

ChucK meets eChucK eChucK has invited ChucK out on a date. She likes ChucK and she thinks they could make beautiful music together. Right now the glue is drying on her stereo audio jacks, but soon with a little wiring she will be ready for her date with ChucK. OK, that was weird but it's true. I'm adding a line-in / headphones-out audio interface to the eChucK Karplus Strong prototype and when that's ready I'll connect eChucK and ChucK together with two 1/8" audio cables. Tonight I'll be writing the ChucK program and over the next few days I should be able to make this happen. In other good news, I'm looking into having the boards populated by the board house so that anyone can just buy one instead of having to DIY with a soldering iron. So far five of the boards have been pre-ordered and I want two of them, so that's seven boards. We might as well use the profits to make 10 of them and break even on the first run of boards. It's like some kind of natural high getting all the feedback from my DIY friends and enjoying this project as it progresses rapidly. I'll keep you posted. Keep on ChucKin' Les

1 0

Re: [chuck-users] Filter instability (Kassen)
by Perry R Cook 12 Nov '09

12 Nov '09

Interesting Kas, Before I go off into the Z Plane (I often don't return from there with all my marbles, but usually with new insights, sort of like a peyote vision- quest), are you changing the filter parameters fairly rapidly in time? Even stable filters can behave unstable when you change the coefficients, especially repeated changes, like sweeps. PRC ----- chuck-users-request(a)lists.cs.princeton.edu wrote: > Send chuck-users mailing list submissions to > > chuck-users(a)lists.cs.princeton.edu > > > > To subscribe or unsubscribe via the World Wide Web, visit > > https://lists.cs.princeton.edu/mailman/listinfo/chuck-users > > or, via email, send a message with subject or body 'help' to > > chuck-users-request(a)lists.cs.princeton.edu > > > > You can reach the person managing the list at > > chuck-users-owner(a)lists.cs.princeton.edu > > > > When replying, please edit your Subject line so it is more specific > > than "Re: Contents of chuck-users digest..." > > > > Today's Topics: > > > > 1. Filter instability (Kassen) > > > > _______________________________________________ > > chuck-users mailing list > > chuck-users(a)lists.cs.princeton.edu > > https://lists.cs.princeton.edu/mailman/listinfo/chuck-users

2 1

Filter instability
by Kassen 12 Nov '09

12 Nov '09

Dear list, Here; http://electro-music.com/forum/viewtopic.php?t=37921 is a discussion on instability in the "convenience filters", particularly LPF. It seems like LPF sometimes goes unstable while I feel that a filter with this purpose (quick&easy filtering with no need to do z-plane transforms ourselves) shouldn't go unstable. Could rounding errors in 64bit floats really cause issues this bad? Are we verifying that the coefficients we get are indeed stable after rounding? That last one is what I'd bet on as a cause for this, but I couldn't do a z-plane transform to save my life. If one of our residential DSP wizards could kindly have a look at that? Maybe Perry? Yours, Kas.

2 1

Re: [chuck-users] Laptop Battle
by Les Hall 10 Nov '09

10 Nov '09

Oh, yes, I forgot about that one I call "Kassen's Phasor". I actually recoded it and used it in this year's Laptop Battle. What I did was write a "popG()" routine that calls an event everytime I quickly extend my hand toward the audience and then quickly retract it. This had the effect of seeming like I was launching "phasors" out of my hand at the audience. Now that you mention it, Hans, I could adopt the same effect to make the sound of ripping a hole in the fabric of space-time! Maybe filter and reverb it too. Thanks for the idea! Les

1 0

Laptop Battle
by Les Hall 10 Nov '09

10 Nov '09

This year at the electro-music 2009 festival, I did the ChucK community proud by winning the Laptop Battle along with a guy who played some awesome guitar (there were two winners this year). My routine was good, but for next year the electro-music 2008 Laptop Battle winner has thrown down the gauntlet and challenged me to a new five-minute timed battle! It's all in good fun, of course, yet I take the competition seriously. My performance will consist of a program controlled by one or two accelerometer boards such that when I move my hand(s) around, ChucK makes noise. I'll do dance or Tai Chi type motions and generate sound from ChucK that will thrill the audience! Right now I'm just collecting sounds to later stitch together into an application. Already kijjaz and I have created some very nice Thunder and Cannon Fire (posted to the wiki if you want the code), yet what is still lacking are two sounds: Lightning and what I can only call "Ripping a Hole in the Fabric of Space-Time", an eerie and ominous sound made by sweeping a hand from side to side. Maybe I'll light up some traffic flares and hold them in my hands during the performance for dramatic effect? Anyway, I'm calling on the ChucK community to provide me with some awesome engaging sounds. The battle isn't until September so we have lots of time to work on this, though I'd like to get something fleshed out in the next few months so I can practice and use the routine at sooner festivals. So give me your best! If you only have an idea for an algorithm, that will do nicely, I'll code it up and test it... You got your game on? Les (Inventor) For those about to ChucK we salute you! - Ge Wang!

3 3