October 2008 - chuck-users - lists.cs.princeton.edu

Re: [chuck-users] Electronic ChucK
by inventor-66＠comcast.net 03 Oct '08

03 Oct '08

Wow. I posted to the ChucK forum about EChucK and some nice person copied the post, cited the origin, and put it on an RSS Feed for synthesizers. This quick little EChucK web page that I worked on all night has now gotten close to 300 hits! That's a lot more than my usual 20 hits a day for the whole music site. There hasn't been much response other than a lot of web hits, but google and my hit counter say they are mostly from unique users, so a lot of people are taking a look at EChucK. The web being what it is, I have heard and found myself that I only get about one email per 1,000 web hits so I'm not surprised nobody has emailed yet. In other good news, the poll I put on the announcement indicates that four people are willing to help out with the project. So it's been an exciting night. Note that the EChucK web page has been expanded and now has sub-pages with JPGs, design files, standards, projects, links and a FAQ. So have a look, the page again is here: http://www.freedomodds.com/music/echuck/ Keep on ChucKin'! Les (Inventor)

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Re: [chuck-users] Electronic ChucK
by inventor-66＠comcast.net 02 Oct '08

02 Oct '08

Thanks for your posts, folks, you're making this fun! I have completed the Power board and the ADC microphone board and I will put them on my website for you to download. The CAD tool of choice is Eagle, which is freeware for making small boards for educational use. Eagle is cross-platform to Windows and Mac, not sure about Linux but it might be. As a professional I used these types of CAD programs for 20 years and I can say that Eagle is a good one and I am enjoying the learning process. Regarding Spencer's topic of digital communication of analog signals, PICs are great at PWM and I2C. You can get a PIC chip for a few dollars US that has PWM and I2C modules, oh, and ADC also. Quite frankly, the main cost problem is the connectors which go for about 50 cents US per node. The PIC boards would not be expensive. I'm putting down footprints for the connectors and saying they are optional. Poor man's solution is to solder the interconnect and cut his cost in half. Poor woman's solution is the same, lol. let's be politically correct. No, poor woman's solution is to get a man to do the soldering for her, they are smart that way, lol. But I digress. I see each PIC processor not only functioning as a UGen, but also as a class. It's an encapsulated module with a clearly defined I2C digital interface, so treat it like a class. Different PICs access each other's private variables across the I2C and they share analog signals by PWM. To convert PWM to analog for interfacing from a PIC audio to an analog audio signal, we just use a passive or active low-pass filter module. To connect the other way we use the ADC input of the PICs. Regarding Kassen's mention of a ChucK interface, we can simply use the line-in jack for stereo input and the headphone jack for stereo output. If you have a soundcard then you can use that. Digital I/O can be done along these same interfaces. So yes, ChucK plugs into your sproingy mass of UGens and PICs. Since there appears to be interest, and I presume someday possibly actual board fabrication, I will begin a web page dedicated to EChucK. As time permits, I will put together some fun and interesting stuff to explore on the page. Does anyone have any suggestions about how to organize the page? I figure a title page with links to many topic pages. Cheers and as Ge would say, "Rock On!" Les (Inventor)

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Re: [chuck-users] Electronic ChucK
by inventor-66＠comcast.net 02 Oct '08

02 Oct '08

Kassen, Your point is well taken. I guess I'm not concerned about the audiophile quality of this system at all. If it's going to be so inexpensive then it will probably be inaccurate as well, and I'm OK with that. It's not intended to produce perfectly orchestrated audio, but rather to do something fun and interesting. Also, that 555 example was indeed for a variable frequency oscillator, more specifically a pulse position modulator from the data sheet. there is a CV input that stops the oscillator at ground and sets maximum frequency at Vcc. Though to get a 50% duty cycle one must add a flip-flop to the output. I'm really just going for a cool toy that will make lights blink and go woo-woo when I put together a ring of oscillators, this does not have to be super precise. That and the limited types of modulation input kind of make for a departure from ChucK, however. But that's OK too. It can simply be ChucK-inspired not ChucK duplicated. Les (Inventor)

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Re: [chuck-users] Electronic ChucK
by inventor-66＠comcast.net 02 Oct '08

02 Oct '08

OK, regarding cost concerns, I have thought this out a little but have not done thorough cost estimation. A SqrOsc can be made with a 555 chip, four resistors and two caps plus two connectors. That's only about five dollars in parts, most of it in the dang connectors. Gain block? put four of them on a single board for not much more. A general purpose, PIC processor based unit would be about the same or maybe two dollars more. Remember, Arduino is a big chip with lots of support components, while the smaller of the PIC family cost $2 and are a total system on a chip. In fact, most of the cost is in the screw-type terminals so if we were to make the system be solderable with just vias (holes) for terminals, the cost per UGen goes down to just $2 on average. And with surface mount parts the board size for a UGen goes down to about the size of a postage stamp so you get *many* UGens on a full-size board. As to closely following ChucK, this is a good point. I imagine that if this catches on, other people will create all sorts of UGens that are not constrained by ChucK at all. I had originally envisioned it months ago as a free-form system in which you can build any module that works, and it was only this morning in the wee hours that I got the inspiration to model it after ChucK. So yeah, it will probably get way different from ChucK in practice if it ever happens. I don't know what direction to take it, but I tell you what. I'm working on it. I'm using Eagle CAD to draw up some basic initial UGens. I am completing the first one, which is a battery power module, and I'm not worrying about making it perfect or adding a wall-wart jack or anything like that. I figure the early modules will get abandoned over time so they are just to get *something* up and running to start with, and they will all get replaced anyway. One cool thing is that the modules are so simple that the freeware version of Eagle can be used to design and manufacture them. I'd like to begin establishing some standards that are not written in stone, but are recommended guidelines. Let's discuss these standards and I'll start a web page for all to read up on the whole thing. The standards are: 1. Use Eagle CAD 2. +5V single supply power 3. analog and digital signals swing from gnd to +5V 4. artificial ground is +2.5V That's all I have so far. I am happy to see the responses to my messages, this is getting to be fun (which is the whole idea)! Cheers! Les (Inventor)

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Re: [chuck-users] Evaluating an argument as anything but a string
by Joel Matthys 01 Oct '08

01 Oct '08

Hi Andrew. There is a handy command in the Std library for doing exactly that, Std.atof. (That's short for ASCII to float.) float harm; string arg1; me.arg(0) => arg1; arg1 => Std.atof => harm; or you can shorten it to: me.arg(0) => Std.atof => harm; Hope this helps! Joel ----- Original Message ---- From: Andrew C. Smith <acsmith(a)willamette.edu> To: chuck-users(a)lists.cs.princeton.edu Sent: Wednesday, October 1, 2008 7:55:38 PM Subject: [chuck-users] Evaluating an argument as anything but a string Hey all, Long time listener, first time caller. I'm a little bit new to this, but I managed to write a program that uses LiSa to play a sample of a piano harmonic at a specified rate, putting it at a specified partial. Here's the deal: I want to just do chuck harmonic.ck:4 for the 4th partial, or chuck harmonic.ck:5 for the 5th, but it keeps telling me that my arguments are strings, not floats. Is there a way to do a string-float conversion, or just even to read a particular argument as a float? float harm; string arg1; me.arg(0) => arg1; ... arg1 => harm; is all I have relating to the arguments. Obviously, that doesn't work, as you can't ChucK a string to a float. There's probably a simple answer to this, isn't there? Andrew Smith _______________________________________________ chuck-users mailing list chuck-users(a)lists.cs.princeton.edu https://lists.cs.princeton.edu/mailman/listinfo/chuck-users

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Re: [chuck-users] Electronic ChucK
by inventor-66＠comcast.net 01 Oct '08

01 Oct '08

Kassen, the reinvention notion is valid, but with a twist. The twist is a physical one. You see, I have not described it completely, now I'll try more. Instead of being mounted in a rack, each module is a little circuit board. Instead of having front panels, each module has PCB-mount thumbwheel pots and little bitty PCB-mount switches. Instead of banana jacks, each module has row-style screw terminal connectors. Instead of banana jack wire, each module is interconnected with solid wire stripped at the ends. One can then form structures, like kijjaz's thunder block diagram that we investigated on the forum. You just chain the modules together rather than "patch" them. Also geometric structures like a ring of oscillators will look physically like, um, a ring. One can construct a Bucky Ball out of filters and SinOscs just to see what it sounds like. It's kind of like making a flowchart or code diagram in which each block is an actual hardware module. So yes, it's a modular synth, but no it isn't quite the same beast. You would purchase a circuit board the size of a piece of notebook paper (81/2 x 11 inches) (A4 size) and then cut or twist off the 30 or 50 or so little bitty circuit boards that were on it. AlgoMantra, cool on the crickets notion. That stuff and much more is so possible with this approach. I see parents buying kids a kit consisting of all you need to get started, and then you can buy add-on boards for like ten bucks each as they are all super small and cheap. Or just buy multiple sheets of boards. They are all held together by solid wire so that they hold their physical form if you make a Christmas tree out of them, well, that's what you get. I plan to make initial boards with 555 timers and opamps and the like, linear you know, but eventually it will make sense to create a PIC-based general purpose board that can be programmed by a PC to be a SinOsc or a multiplier or a whatever thingie. To facilitate the language features of ChucK we could use a serial interface such as I2C or other PIC-supported interface and let the programs exchange information like shreds. I'm interested in discussing standards such as what voltage levels to use and whatnot, plus I'm starting to learn Eagle PCB CAD by making little circuit board designs, beginning with a power module. Whew, typed a lot - as you can see I find the idea exciting. I'm working on it now. DigiKey has the parts, and us - we got the smarts, haha! I'm calling it EChucK for now. Comments welcome as always. Les (Inventor)

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Evaluating an argument as anything but a string
by Andrew C. Smith 01 Oct '08

01 Oct '08

Hey all, Long time listener, first time caller. I'm a little bit new to this, but I managed to write a program that uses LiSa to play a sample of a piano harmonic at a specified rate, putting it at a specified partial. Here's the deal: I want to just do chuck harmonic.ck:4 for the 4th partial, or chuck harmonic.ck:5 for the 5th, but it keeps telling me that my arguments are strings, not floats. Is there a way to do a string-float conversion, or just even to read a particular argument as a float? float harm; string arg1; me.arg(0) => arg1; ... arg1 => harm; is all I have relating to the arguments. Obviously, that doesn't work, as you can't ChucK a string to a float. There's probably a simple answer to this, isn't there? Andrew Smith

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Electronic ChucK
by inventor-66＠comcast.net 01 Oct '08

01 Oct '08

Hi folks, I have this Idea and let me know if it's crazy as many of my ideas are, but I think it's a good one: electronic ChucK. The concept is to build little bitty circuit boards that each model a ChucK UGen. Naturally the more complex ones like the instruments are too complex to attempt initially, but the simple ones like gain, SqrOsc, LPF and the like can be easily constructed. Once these modules are available in physical form as little circuit boards, a user can hook them up just like a ChucK patch. Some of the programming aspects of ChucK can also be modeled with PIC processor modules. I envision using the miniature screw-terminals available for interconnect so that the electronic ChucKist can hook them up with wire. If solid wire is used, one could construct geometric structures that occupy physical space in three dimensions. There would be support modules such as a power module, a dac module, and some types of adc modules, plus LED modules, etc. I am interested in your opinion of the project as I believe that ChucKists work better as a group than individually. I would make the schematics and layout files available for free on the internet and also I would do production runs of the boards for people who wanted to just buy the thing instead of DIYing it. What are your thoughts? Les (Inventor)

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