I'm writing a proposal for independent study at my school, and my goal is to take a few lessons in tuning from this microtonal composer, compose a piece using my Pd sequencer, and somehow use the output to drive the newly refurbished Moog at my school (supposedly one of the first 5 Moogs ever made) to create a finished track.
MIDI-to-CV converters are expensive, and of course MIDI is already inadequate. So I'm thinking of circuits I've looked at before and wondering if plain old audio from [sig~] objects could be made to represent voltage, from -1 to 1, or 0 to 1 with -1 being off, and externally converted to the proper scale for CV input to the Moog. The music tech supervisor has added a module that makes the thing polyphonic, which I suppose I'll have to understand to do it. I guess my other option is to just use audio output, and process it through the Moog's modules.
Can anyone make any suggestions? How can one interface between Pd and control voltage? Could I jury-rig regular audio output to do it?
Thanks.
-Chuckk
You could maybe use the Arduino interface for this, but I know jack squat about the Arduino right now. Has anyone done this?
~Kyle
On 9/11/06, Chuckk Hubbard badmuthahubbard@gmail.com wrote:
I'm writing a proposal for independent study at my school, and my goal is to take a few lessons in tuning from this microtonal composer, compose a piece using my Pd sequencer, and somehow use the output to drive the newly refurbished Moog at my school (supposedly one of the first 5 Moogs ever made) to create a finished track.
MIDI-to-CV converters are expensive, and of course MIDI is already inadequate. So I'm thinking of circuits I've looked at before and wondering if plain old audio from [sig~] objects could be made to represent voltage, from -1 to 1, or 0 to 1 with -1 being off, and externally converted to the proper scale for CV input to the Moog. The music tech supervisor has added a module that makes the thing polyphonic, which I suppose I'll have to understand to do it. I guess my other option is to just use audio output, and process it through the Moog's modules.
Can anyone make any suggestions? How can one interface between Pd and control voltage? Could I jury-rig regular audio output to do it?
Thanks.
-Chuckk
-- "Far and away the best prize that life has to offer is the chance to work hard at work worth doing." -Theodore Roosevelt
PD-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Pitch to CV, Envelope Followers and Gates might be of use.
That is one classic Moog there - the guy who did the refurb makes some great synth gear himself. Make good use of it.
On 9/11/06, Chuckk Hubbard badmuthahubbard@gmail.com wrote:
I'm writing a proposal for independent study at my school, and my goal is to take a few lessons in tuning from this microtonal composer, compose a piece using my Pd sequencer, and somehow use the output to drive the newly refurbished Moog at my school (supposedly one of the first 5 Moogs ever made) to create a finished track.
MIDI-to-CV converters are expensive, and of course MIDI is already inadequate. So I'm thinking of circuits I've looked at before and wondering if plain old audio from [sig~] objects could be made to represent voltage, from -1 to 1, or 0 to 1 with -1 being off, and externally converted to the proper scale for CV input to the Moog. The music tech supervisor has added a module that makes the thing polyphonic, which I suppose I'll have to understand to do it. I guess my other option is to just use audio output, and process it through the Moog's modules.
Can anyone make any suggestions? How can one interface between Pd and control voltage? Could I jury-rig regular audio output to do it?
Thanks.
-Chuckk
-- "Far and away the best prize that life has to offer is the chance to work hard at work worth doing." -Theodore Roosevelt
PD-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
On 9/11/06, chris clepper cgclepper@gmail.com wrote:
Pitch to CV, Envelope Followers and Gates might be of use.
I saw something about envelope followers online. It seems like that ought to do it, with some manual adjustments as always. Pitch to CV I would love to do, I have no idea how. Also, a friend suggested generating PWM from my serial port and filtering it. I don't know exactly how a Moog's PWM works, but from his description I thought I might just as well generate sine, ramp, square, triangle and pulse waves in Pd and run them through the filters and envelopes on the synth. And where's the fun in that? But if no other possibilities work out, I can use that.
That is one classic Moog there - the guy who did the refurb makes some great synth gear himself. Make good use of it.
You mean http://www.discretesynthesizers.com/arptronics/satis.htm ? That's my freshman theory and current acoustics teacher standing between Bob Moog and Tom Porett. He says he was friends with Dr. Moog way back. He's never said, but I take it that's how my school ended up with the thing. I got lucky; freshman year it was not possible to even be in the same room with it, now I've been explicitly offered the chance to learn on it.
-Chuckk
On 9/11/06, Chuckk Hubbard badmuthahubbard@gmail.com wrote:
I'm writing a proposal for independent study at my school, and my goal is to take a few lessons in tuning from this microtonal composer, compose a piece using my Pd sequencer, and somehow use the output to drive the newly refurbished Moog at my school (supposedly one of the first 5 Moogs ever made) to create a finished track.
MIDI-to-CV converters are expensive, and of course MIDI is already inadequate. So I'm thinking of circuits I've looked at before and wondering if plain old audio from [sig~] objects could be made to represent voltage, from -1 to 1, or 0 to 1 with -1 being off, and externally converted to the proper scale for CV input to the Moog. The music tech supervisor has added a module that makes the thing polyphonic, which I suppose I'll have to understand to do it. I guess my other option is to just use audio output, and process it through the Moog's modules.
Can anyone make any suggestions? How can one interface between Pd and control voltage? Could I jury-rig regular audio output to do it?
Thanks.
-Chuckk
-- "Far and away the best prize that life has to offer is the chance to work hard at work worth doing." -Theodore Roosevelt
PD-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Chuckk Hubbard wrote:
On 9/11/06, chris clepper cgclepper@gmail.com wrote:
Pitch to CV, Envelope Followers and Gates might be of use.
I saw something about envelope followers online. It seems like that ought to do it, with some manual adjustments as always. Pitch to CV I would love to do, I have no idea how. Also, a friend suggested generating PWM from my serial port and filtering it. I don't know exactly how a Moog's PWM works, but from his description I thought I might just as well generate sine, ramp, square, triangle and pulse waves in Pd and run them through the filters and envelopes on the synth. And where's the fun in that? But if no other possibilities work out, I can use that.
You can generate control voltage from a pulse-width modulated square wave in pd. Put an envelope follower circuit on the soundcard output and probably some more gain. You can do that with a quad op-amp. Problem is ripple in the output that can be mitigated at the cost of more portamento. The more resolution you want the lower the PWM frequency has to be for a fixed sample rate. That's maybe not a problem for 12 notes per octave but microtonality needs more precision, so the base frequency will drop and so your lowpass filter needs to go lower still and then your notes tend to glide a bit going from one to the next or else you get FM from the PWM frequency. Another way to do it is to output something like 22kHz constant frequency wave but vary the volume. Then the low-pass filter can be around 1kHz and you can get thousands of levels with a 16bit soundcard. You might be able to do the envelope follower with just a diode and a capacitor but a better solution would use op-amps to buffer the voltage. If you're doing something that relies on precise tuning you ought to make a good cv generator. I built my own MIDI to CV (and gate and trig, don't forget) converters that use a PIC16F628 and a 16bit DAC for 65536 levels on 0-10V for my analog synths, for less than $50 parts. You could also interface a serial DAC to an arduino. But I bet you could do it with a cheapo soundcard as well if you can find the output of the dac before it passes through any capacitor. You need to pass that through a simple op-amp amplifier to add gain and offset to get from +-1V to the 0-10V range. Then write a dc external for pd that outputs a constant value instead of a signal (maybe line~ already does that).
Martin
Instead of adding more portamento for finer pitch resolution, would it be possible to do different registers separately? Since I intend to compose the entire piece before passing it through the Moog, and my patch handles all the tempos, it would not be a problem to record the audio in segments and line them up in Pro Tools. I suppose the wandering tuning of the synth itself will be an issue.
I like your very last suggestion. I realized through some preliminary investigations with a multimeter that my soundcard removes DC pretty quickly. I guess your point about the 22kHz constant frequency is that this would not happen. For the op-amp idea, would a signal not be sufficient? I thought [sig~ .4], for instance, would output a constant value of .4?
Another thing I didn't mention is that the only computer in the same room as the Moog is a university Mac, which I won't be able to tear open. I don't yet own a working laptop, so if anything like that needs to be done, it will be me bringing my PC to school. I think this will still be easier for me than the PWM squarewave, which I still don't understand.
Thanks for your help.
-Chuckk
On 9/11/06, Martin Peach martin.peach@sympatico.ca wrote:
Chuckk Hubbard wrote:
On 9/11/06, chris clepper cgclepper@gmail.com wrote:
Pitch to CV, Envelope Followers and Gates might be of use.
I saw something about envelope followers online. It seems like that ought to do it, with some manual adjustments as always. Pitch to CV I would love to do, I have no idea how. Also, a friend suggested generating PWM from my serial port and filtering it. I don't know exactly how a Moog's PWM works, but from his description I thought I might just as well generate sine, ramp, square, triangle and pulse waves in Pd and run them through the filters and envelopes on the synth. And where's the fun in that? But if no other possibilities work out, I can use that.
You can generate control voltage from a pulse-width modulated square wave in pd. Put an envelope follower circuit on the soundcard output and probably some more gain. You can do that with a quad op-amp. Problem is ripple in the output that can be mitigated at the cost of more portamento. The more resolution you want the lower the PWM frequency has to be for a fixed sample rate. That's maybe not a problem for 12 notes per octave but microtonality needs more precision, so the base frequency will drop and so your lowpass filter needs to go lower still and then your notes tend to glide a bit going from one to the next or else you get FM from the PWM frequency. Another way to do it is to output something like 22kHz constant frequency wave but vary the volume. Then the low-pass filter can be around 1kHz and you can get thousands of levels with a 16bit soundcard. You might be able to do the envelope follower with just a diode and a capacitor but a better solution would use op-amps to buffer the voltage. If you're doing something that relies on precise tuning you ought to make a good cv generator. I built my own MIDI to CV (and gate and trig, don't forget) converters that use a PIC16F628 and a 16bit DAC for 65536 levels on 0-10V for my analog synths, for less than $50 parts. You could also interface a serial DAC to an arduino. But I bet you could do it with a cheapo soundcard as well if you can find the output of the dac before it passes through any capacitor. You need to pass that through a simple op-amp amplifier to add gain and offset to get from +-1V to the 0-10V range. Then write a dc external for pd that outputs a constant value instead of a signal (maybe line~ already does that).
Martin
Chuckk Hubbard wrote:
Instead of adding more portamento for finer pitch resolution, would it be possible to do different registers separately?
I don't get it. I didn't mean to suggest adding portamento. That's a drawback of PWM: you can't switch quickly between levels and have a pure DC level at the same time: the voltage ramps up or down.
Since I intend to compose the entire piece before passing it through the Moog, and my patch handles all the tempos, it would not be a problem to record the audio in segments and line them up in Pro Tools. I suppose the wandering tuning of the synth itself will be an issue.
You could use pd to tune the synth: count the frequency and compare it to what it should be, change the CV. The Oberheim Xpander does that to overcome the limitations of its 8-bit main DAC.
I like your very last suggestion. I realized through some preliminary investigations with a multimeter that my soundcard removes DC pretty quickly. I guess your point about the 22kHz constant frequency is that this would not happen.
It still happens but it's easier to filter out the 22kHz than the 22Hz or so that PWM would need. You have to add the DC back in by passing the signal through a diode somewhere, the easiest circuit looks like this but it will be too noisy: diode in --->|----+-------out | = capacitor | gnd Basically the diode forces all the voltage to be positive relative to the average voltage held on the capacitor. With a high enough input frequency and a large enough capacitor you get a steady DC voltage. The capacitor stores charge, the larger it is the slower the output changes. If it's too small the input frequency passes through, which you don't want.
For the op-amp idea, would a signal not be sufficient? I thought [sig~ .4], for instance, would output a constant value of .4?
Probably that would work. The actual voltage you get from a soundcard is probably too low by a factor of ten so you need to amplify it somehow, usually with an op-amp.
Another thing I didn't mention is that the only computer in the same room as the Moog is a university Mac, which I won't be able to tear open. I don't yet own a working laptop, so if anything like that needs to be done, it will be me bringing my PC to school. I think this will still be easier for me than the PWM squarewave, which I still don't understand.
The PWM idea is simple: it's to average the wave. If it's 25% on, 75% off you get an average level of 25% full-scale. To get the average level you low-pass filter it at a very low frequency, which then limits how fast you can change the level. And if you're sampling at 44100Hz and need 1000 different levels you have to use a frequency of 44.1 Hz for the PWM frequency.
Martin
You may want to query the guys on the music-dsp list also. There seem to be some real analogue gurus on that one.
~Kyle
On 9/11/06, Martin Peach martin.peach@sympatico.ca wrote:
Chuckk Hubbard wrote:
Instead of adding more portamento for finer pitch resolution, would it be possible to do different registers separately?
I don't get it. I didn't mean to suggest adding portamento. That's a drawback of PWM: you can't switch quickly between levels and have a pure DC level at the same time: the voltage ramps up or down.
Since I intend to compose the entire piece before passing it through the Moog, and my patch handles all the tempos, it would not be a problem to record the audio in segments and line them up in Pro Tools. I suppose the wandering tuning of the synth itself will be an issue.
You could use pd to tune the synth: count the frequency and compare it to what it should be, change the CV. The Oberheim Xpander does that to overcome the limitations of its 8-bit main DAC.
I like your very last suggestion. I realized through some preliminary investigations with a multimeter that my soundcard removes DC pretty quickly. I guess your point about the 22kHz constant frequency is that this would not happen.
It still happens but it's easier to filter out the 22kHz than the 22Hz or so that PWM would need. You have to add the DC back in by passing the signal through a diode somewhere, the easiest circuit looks like this but it will be too noisy: diode in --->|----+-------out | = capacitor | gnd Basically the diode forces all the voltage to be positive relative to the average voltage held on the capacitor. With a high enough input frequency and a large enough capacitor you get a steady DC voltage. The capacitor stores charge, the larger it is the slower the output changes. If it's too small the input frequency passes through, which you don't want.
For the op-amp idea, would a signal not be sufficient? I thought [sig~ .4], for instance, would output a constant value of .4?
Probably that would work. The actual voltage you get from a soundcard is probably too low by a factor of ten so you need to amplify it somehow, usually with an op-amp.
Another thing I didn't mention is that the only computer in the same room as the Moog is a university Mac, which I won't be able to tear open. I don't yet own a working laptop, so if anything like that needs to be done, it will be me bringing my PC to school. I think this will still be easier for me than the PWM squarewave, which I still don't understand.
The PWM idea is simple: it's to average the wave. If it's 25% on, 75% off you get an average level of 25% full-scale. To get the average level you low-pass filter it at a very low frequency, which then limits how fast you can change the level. And if you're sampling at 44100Hz and need 1000 different levels you have to use a frequency of 44.1 Hz for the PWM frequency.
Martin
PD-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Martin Peach wrote:
If you're doing something that relies on precise tuning you ought to make a good cv generator. I built my own MIDI to CV (and gate and trig, don't forget) converters that use a PIC16F628 and a 16bit DAC for 65536 levels on 0-10V for my analog synths, for less than $50 parts. You could also interface a serial DAC to an arduino.
and as i just discovered, you can order free samples with free next-day shipping from most of the manufacturers, making it much less than $50 parts. see for example http://sample.microchip.com/
hi chuck,
Am Dienstag, 12. September 2006 00:05 schrieb Chuckk Hubbard: [...snip...]
Can anyone make any suggestions? How can one interface between Pd and control voltage? Could I jury-rig regular audio output to do it?
Thanks.
-Chuckk
a cheap solution is to use a parallel port, a bunch of latches with 3-state output (74hc 373, 573, etc....), a bcd-to-binary decoder or equivalent (like 74hc42, or 74hc259) and a pack of resistors to build a r-2r dac.
the idea is as follow: you connect the data inputs of all latches to the 8 data pins of the parport (in parallel, that is). from the 4 control output lines, you connect 3 to the decoder (so you can address 8 latches, = 4 outputs with 16 bits), and the fourth line as output-enable to the latches. combine two latches to have a 16 bit value (or 3 for 24 bits, etc...) at the output of the r-2r dac string, put a small hold capacitor. feed that into a opamp buffer or gain-stage.
to control: disable all latch outputs by toggling the single enable-line. select the latch to load the data into, apply the data byte. then select next latch, apply next data byte, and so .... when you loaded the last latch, toggle the enable line again to output the data into the dac's.
since the latch outputs are disabled (in open-state) during the loading, the capacitor will hold the previous voltage.
you can connect the same schema to an arduino as well, for example. that way you can even use a 4-to-16 binary decoder to control 16 different latches, and use an extra line for a dedicated load pulse (so you can share the 8 lines from the data bus with other peripherials, if you need to)
this solution should cost you below 4 dollars per 16 bits.
another way is to use some serial dac's, but they usually come in smd packagings only, making them harder to solder. you may check www.ti.com for dac's and request some free samples, so you can play around without paying anything for them ....
btw, you can connect such serial dac's to the parport as well. you can even connect 8 of them at once, each with a dedicated data line, but all with shared control lines. that way you can update 8 dac outputs at the same time, without any delay between them. if you get the dac's as samples, this solution will cost you virtually nothing ;)
greets,
chris
On Tue, Sep 12, 2006 at 07:14:14AM +0200, Christian Klippel wrote:
btw, you can connect such serial dac's to the parport as well. you can even connect 8 of them at once, each with a dedicated data line, but all with shared control lines. that way you can update 8 dac outputs at the same time, without any delay between them. if you get the dac's as samples, this solution will cost you virtually nothing ;)
You can even make an ÃŒber cheap awful sounding 8 bit "soundcard" like that and drive it by sending 8 bit sample values directly to the parallel port.
Best,
Chris.
chris@mccormick.cx http://mccormick.cx
dude, get on the #dataflow irc channel and talk to people there....they know EVERYTHING
On 12/09/2006, at 8.43, Chris McCormick wrote:
You can even make an über cheap awful sounding 8 bit "soundcard" like that and drive it by sending 8 bit sample values directly to the
parallel port.
I'd be very interested to know how - do you care to elaborate or
direct to appropriate information regarding this?
best, steffen
hi steffen,
i'd like to refer you to the right keywords:
covox speech thing & disney sound source
in wikipedia: http://en.wikipedia.org/wiki/Covox_Speech_Thing
greets,
chris
Am Dienstag, 12. September 2006 18:22 schrieb Steffen:
On 12/09/2006, at 8.43, Chris McCormick wrote:
You can even make an über cheap awful sounding 8 bit "soundcard" like that and drive it by sending 8 bit sample values directly to the parallel port.
I'd be very interested to know how - do you care to elaborate or direct to appropriate information regarding this?
best, steffen _______________________________________________ PD-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
On Tue, 12 Sep 2006, Christian Klippel wrote:
hi steffen, i'd like to refer you to the right keywords: covox speech thing & disney sound source in wikipedia: http://en.wikipedia.org/wiki/Covox_Speech_Thing
Btw, the first MOD player I've ever used, had plans for a Covox straight in its manual. I didn't build one, though I really SHOULD have. It would have bridged the gap between 1-bit PC Speakers and the 320$ 8-bit SoundBlaster that my parents had.
Note that the 1-bit PC Speaker didn't really sound like 1-bit in that program, due to some serious oversampling: The program introduced ultrasounds which were then hardware-lowpassed into intermediate speaker positions. Still, a covox would have sounded much better... or at least, a cable going out to a real speaker...
_ _ __ ___ _____ ________ _____________ _____________________ ... | Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju | Freelance Digital Arts Engineer, Montréal QC Canada
On Tue, Sep 12, 2006 at 06:22:32PM +0200, Steffen wrote:
On 12/09/2006, at 8.43, Chris McCormick wrote:
You can even make an ÃŒber cheap awful sounding 8 bit "soundcard" like that and drive it by sending 8 bit sample values directly to the
parallel port.I'd be very interested to know how - do you care to elaborate or
direct to appropriate information regarding this?
Christian pointed me here: http://en.wikipedia.org/wiki/Covox which is an (ancient) commercial implementation of the idea and tells you pretty much everything you need to know. The key is to get very accurately matched resistors. It's a lot of fun actually, to build yr own soundcard that can be used by popular software such as wolfenstein 3d and fasttracker II. ;)
Best,
Chris.
chris@mccormick.cx http://mccormick.cx
On 12/09/2006, at 18.42, Chris McCormick wrote:
Christian pointed me here: http://en.wikipedia.org/wiki/Covox
Thanks to you both. Interesting read indeed. It could be a fun time- off project at one point.
Best, Steffen
On 12/09/2006, at 7.14, Christian Klippel wrote:
a cheap solution is to use a parallel port [snip]
Given that the "university Mac" - mentioned earlier - hasn't been
born with a parallel port, but most likely haven been born with
atleast an usb port. Will a solution be as easy as getting a usb-to-
parallel adapter?
I think this muct of interest for Chuckk Hubbard, but it is of my own
interest aswell.
best, steffen
hi steffen,
Am Dienstag, 12. September 2006 18:30 schrieb Steffen:
On 12/09/2006, at 7.14, Christian Klippel wrote:
a cheap solution is to use a parallel port [snip]
Given that the "university Mac" - mentioned earlier - hasn't been born with a parallel port, but most likely haven been born with atleast an usb port. Will a solution be as easy as getting a usb-to- parallel adapter?
well, you could go and spend some bucks for such a converter, and yes, it shoudl work.
but you can also directly use usb .... get some free samples of the pic18f2455, 2550, 4455 or 4550 from www.microchip.com you need only a few parts to make it work (namely, the usb socket, a crystal and some cap's). the first two are 28 pin devices, if you need more pins, use the latter two, they have 40 pins.
the use the PUF (Pic USB Framework) from http://vasco.gforge.enseeiht.fr/index.php?article=PUF.html
check the odyssey stuff as well, to get a diy programmer & software. dont know about mac (for the programmer part), but sdcc should compile there as well (which is needed to compile the pic source code)
thats all .... you will get an incredibly cheap usb thing with that (the cost for the socket, crystal, etc... maybe 10 bucks in total), which you can freely program in c using the sdcc compiler. once the bootloader in programmed into the pic, all further code updates are done via usb, so you need a pic-programmer only for bootstrap (initial programming of the bootloader)
I think this muct of interest for Chuckk Hubbard, but it is of my own interest aswell.
best, steffen
if there is interrest, i can do a quick schematic of that.
greets,
chris
On 12/09/2006, at 18.47, Christian Klippel wrote:
if there is interrest, i can do a quick schematic of that.
There indeed is! I'm very exited about the any inside on how to use
my USB port to control "things".
As a matter of fact, i also need a CV source to calibrate a newly
made VCO. So i guess a device can be made, such that it can do that
and loads of other things too - like, replacing a MIDI-to-CV module,
control circuit bended toys, ... I understand there might be
conflicting design cretirias, but the idea, the basic idea must be
the same. (insert big happy face here)
If you got the time, that is.
Cheers, Steffen
hi,
Am Dienstag, 12. September 2006 20:26 schrieb Steffen:
On 12/09/2006, at 18.47, Christian Klippel wrote:
if there is interrest, i can do a quick schematic of that.
There indeed is! I'm very exited about the any inside on how to use my USB port to control "things".
As a matter of fact, i also need a CV source to calibrate a newly made VCO. So i guess a device can be made, such that it can do that and loads of other things too - like, replacing a MIDI-to-CV module, control circuit bended toys, ... I understand there might be conflicting design cretirias, but the idea, the basic idea must be the same. (insert big happy face here)
If you got the time, that is.
Cheers, Steffen
alright, will do. but give me some weeks. i'm loaded with work currently, needing to delay a lot of promised things already .... if in doubt, remind me about that in a few weeks....
anyhow, the pure schematic is what you can find in the datasheet for these chips: the oscillator circuit (xtal and 2 cap's), a cap for usb power, the usb socket and finally some electrolytic cap to buffer the +5volt line from the usb bus. thats it. the pin functions are to be coded in c afterwards.
greets,
chris
I'm also really interested on learning how to get "real world" data in and out of PD, via the USB port. Sensors, LED lights, etc etc. I see a lot of conversation about stuff like Arduino, but have no clue what people are talking about mostly.
I'd really like to know the simplest way to get started. I've never soldered anything or messed with hardware, so in some ways it might be nice to pay a little more for something that works "out of the box" and plugs into USB, then to build some kind of kit. I don't know what a minimum cost for something like this would be.
Once I had things working with the pre-built stuff, I could move on to building my own DIY versions.
~David
On 9/12/06, Steffen stffn@dibidut.dk wrote:
On 12/09/2006, at 18.47, Christian Klippel wrote:
if there is interrest, i can do a quick schematic of that.
There indeed is! I'm very exited about the any inside on how to use my USB port to control "things".
As a matter of fact, i also need a CV source to calibrate a newly made VCO. So i guess a device can be made, such that it can do that and loads of other things too - like, replacing a MIDI-to-CV module, control circuit bended toys, ... I understand there might be conflicting design cretirias, but the idea, the basic idea must be the same. (insert big happy face here)
If you got the time, that is.
Cheers, Steffen
PD-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
This sounds tempting, but for my project, it being a university (art school, not EECS) computer, I also don't have access to a C compiler on it. It would be amazing to just walk in and plug a USB adapter into the Mac and a phono plug at the other end into the Moog. Now that I think about it, I believe my only choices are USB, 1394, and audio.
On 9/12/06, Christian Klippel ck@mamalala.de wrote:
well, you could go and spend some bucks for such a converter, and yes, it shoudl work.
but you can also directly use usb .... get some free samples of the pic18f2455, 2550, 4455 or 4550 from www.microchip.com you need only a few parts to make it work (namely, the usb socket, a crystal and some cap's). the first two are 28 pin devices, if you need more pins, use the latter two, they have 40 pins.
the use the PUF (Pic USB Framework) from http://vasco.gforge.enseeiht.fr/index.php?article=PUF.html
check the odyssey stuff as well, to get a diy programmer & software. dont know about mac (for the programmer part), but sdcc should compile there as well (which is needed to compile the pic source code)
thats all .... you will get an incredibly cheap usb thing with that (the cost for the socket, crystal, etc... maybe 10 bucks in total), which you can freely program in c using the sdcc compiler. once the bootloader in programmed into the pic, all further code updates are done via usb, so you need a pic-programmer only for bootstrap (initial programming of the bootloader)
I think this muct of interest for Chuckk Hubbard, but it is of my own interest aswell.
best, steffen
if there is interrest, i can do a quick schematic of that.
greets,
chris
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hi again,
also note that many cv inputs are "adjusted" for 1 volt per octave. so, instead of using a dac over the complete range, you might do a combination of a dac and a switchable gain&shift stage. say, the dac handles 2 octaves, and you have 5 different octave-base selections available.
pro: allows for much finer tuning of the note con: requires more control software and a bit more electronics
a rough guess would be around 8 or 10 bucks per 16 bits / 5 selections. for simplicity i would recommend to use 4 selection with 2 1/2 octaves each, because analog 4-channel switches as chips are readily (and cheaply) available.
greets,
chris
By the way, is there an external that can access USB or serial ports, or is that what everyone means by "you have to code it in C"? -Chuckk
Chuckk Hubbard wrote:
By the way, is there an external that can access USB or serial ports,
[comport] could work on OSX if anyone wanted to port it, at least for USB serial ports. I would do it but I don't have a Mac running OSX. It seems to work on the other two OSs. Martin
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chris clepper -
Chris McCormick -
Christian Klippel -
Chuckk Hubbard -
Damian Stewart -
David Powers -
hard off -
Kyle Klipowicz -
Martin Peach -
Mathieu Bouchard -
Steffen