terminal tedium (raspberry zero, pi2, pi3 codec / pd thing)

[mxmxmx]

***** terminal tedium update (see below for original rpio post)

board w/ stereo codec (pcm5102a or wm8731) and 8 x 12 bit ADC (MCP3208), suitable for use with raspberry pi models pi 2, 3, zero, A+ and B+ (*). 16bit / 48kHz, 10VPP, w/ buffered CV inputs etc



view from behind (w/ wm8731 and w/o rpi attached):



and here's some kind of demo/test (this is the wm8731 version, w/ model A+); the object used is simply disis_munger~ ; two samples coming from eurotrash, into the left and right channel inputs; parameters more or less randomly modulated (grain size, # grains, pitch, delay length, stereo spread) (much the same could thus be achieved with the (old) pcm5102a version using files on the uSD card) :


https://soundcloud.com/menschenimhotel/ ... edium_test


BOM and panel svg is here: https://github.com/mxmxmx/terminal_tedium

build guide here:
https://github.com/mxmxmx/terminal_tedium/wiki


here's the old/rpio demo:

not sure how useful this is in demonstrating the sound quality of the thing ... but here's a few minutes of not-particularly-inspired audio

http://soundcloud.com/menschenimhotel/rpio-1/s-UHNCv


*
NB: models 3A+ and 3B+ are compatible in principle, but won't work out of the box. see here.


original post:

... courtesy of PCM5102A, which is an i2s stereo audio DAC. the point was/is to get decent sound quality at modular synth levels, rather than having to use an usb audio interface or the native pwm output. at any rate, this isn't supposed to show off some pd patch.

.. sorry i didn't come up with something more decent (or at least systematic); truth is, i didn't get round to spending a great deal of time on/with the software side of things, so it's just some fairly straightforward pitch shifting and time-stretching, where pitch and stretch factor are controlled by control voltages (some random-ish sample+hold stuff; not that it's noticeable).

i figured i use some voice sample (suzanne ciani), which is what you can hear the first 10 seconds or so. that's just the wav file (aplay), the remainders is puredata resp. csound. edit: updated the file to make it somewhat less repetitive. it's still just various samples run through a phase vocoder patch; from around 1:00 you'll notice it's actually two rpios, one sounding a bit duller as it went through a
PT2399 based delay, with the feedback cranked up.

the outputs go into a L-1 stereo mixer (one via the delay) then straight into my audio interface. everything is stereo, 16bit 44.1khz (pd) or 48khz (aplay). well, some of the wav files were actually converted from mp3.

[kindredlost]

Always a silly thing to say in the DIY section, but... I'd love to read this module could be built for someone (me hint) or at least a project kit with instructions could hit the market. I have a Phonogene and this would compliment it well.

Good job and nice panel graphic.

[Matos]

Wow! Super interesting! Is there a thread that goes into detail of this project? My search has left me with nothing.

[mxmxmx]

[removed obsolete info]

[crowhurst]

Thumbs up!

I'd also lust for further info on this

[crowhurst]

there's some more details in this thread

ah well - you've beaten me already

[sgnelson]

Very cool, I just bought a raspi to play with for my modular as well, so it's great to see someone doing the same thing.

[webb]

Can't wait for the gerbers to be posted! I haven't done smd yet on my cnc mill but its worth a shot.

[mxmxmx]

[obsolete info]

[sebiiksbcs]

Yessss

[c1t1zen]

I'm loving all these mini-computers inside modular panels! Please let me know if you offer up a DIY kit. Or at least the processes to do it on our own.

Great stuff.

[mxmxmx]

I'm loving all these mini-computers inside modular panels! Please let me know if you offer up a DIY kit. Or at least the processes to do it on our own.

sure, but definitely no kits. even if i had the time to do it, i'd be surprised if i sold 10, so there's no point in buying things in bulk either. it's all commonly available parts, anyways. i will/can, as mentioned, simply post the gerbers. it's just that i want to make sure everything is ok with the revised board before letting it out into the open.

edit: new boards are in


won't get near a soldering iron any time soon though.

[mxmxmx]

build one up now and everything seems to be working out nicely this time round ... slightly improved layout, too. except the two tact switches, which i couldn't fit anywhere else.




bottom side w/ mounting screw. probably should get one of those smallish microSD adapters though.



anyone who got one of the first run of proto boards and hasn't built it yet, let me know, i have a couple of spare boards left.

[rosch]

i'd be interested to build this too, i like the sound.
and i need to do something with my Raspberry

[mxmxmx]

i'd be interested to build this too, i like the sound.
and i need to do something with my Raspberry :hihi:

that was my thinking, i never really used mine.

and sure, i can send you one - doucheland is where i am?

as to the sound, i actually haven't compared things with the native pwm output. i *think* the DAC sounds much nicer (well, it better should have) but that might just be psychological. anyways, i didn't mean to show off the pd patch, that was just put together really quick.

[money bags]

if its possible to program it without a Raspberry I would like one.

[rosch]

i'd be interested to build this too, i like the sound.
and i need to do something with my Raspberry

that was my thinking, i never really used mine.

and sure, i can send you one - doucheland is where i am?

yes BRD, and that would be great!

[mxmxmx]

if its possible to program it without a Raspberry I would like one.

not sure i understand - you don't program it at all, it's entirely dumb just by itself. it's more like a plug-and-play sound card for the raspberry, and a converter so that the rpi can be controlled with control voltages rather than a keyboard (that bit is slightly less plug and play)

you could of course attach any other microcontroller or SoC that comes with SPI and I2S, but in that case i think i'd just use a pcb customised for that specific micro/purpose.

at any rate, without a raspberry or similar, it's not going to do much. (that said, not having to program a great deal (as in DSP) is part of the appeal, it's more about using programs (such as pd or csound)).

[monstrinho]

Just wondering, could this be built with banana jacks, or is there a reason (electronically) that it would need mini-jacks? Also, is the supply voltage critical? (i.e. could it run on +/-15v without modifications)?

[money bags]

if its possible to program it without a Raspberry I would like one.

not sure i understand - you don't program it at all, it's entirely dumb just by itself. it's more like a plug-and-play sound card for the raspberry, and a converter so that the rpi can be controlled with control voltages rather than a keyboard (that bit is slightly less plug and play)

you could of course attach any other microcontroller or SoC that comes with SPI and I2S, but in that case i think i'd just use a pcb customised for that specific micro/purpose.

at any rate, without a raspberry or similar, it's not going to do much. (that said, not having to program a great deal (as in DSP) is part of the appeal, it's more about using programs (such as pd or csound)).

im a little confused. what i really want to know is can i upload PD data from osx? or its only for RPI?

[CJ Miller]

im a little confused. what i really want to know is can i upload PD data from osx? or its only for RPI?

This is basically a breakout board so that one can get signal i/o for using a Raspberry Pi in/as a synth module. PD needs some computer to run on, and this case that is the Raspberry Pi. So you could load patches from another box to the SD card or whatever, and run them in PD on the Pi. I hope I am being clear.

[mxmxmx]

im a little confused. what i really want to know is can i upload PD data from osx? or its only for RPI?

oh, alright, sorry i didn't get it the first time. well yeah, as CJ MILLER said, once the rpi is set up you can pretty much ignore it. i do all the pd stuff on my notebook then just copy it over to the raspberry. there's tons of info on the web re running a pi "headless".

Just wondering, could this be built with banana jacks, or is there a reason (electronically) that it would need mini-jacks? Also, is the supply voltage critical? (i.e. could it run on +/-15v without modifications)?

mmh, i haven't ever used banana jacks, so i can't really tell. i would have guessed you'd be okay except i don't know how banana people prevent inputs from floating. when using 3.5mm jacks the inputs to the ADC are tied to ground when nothing is plugged,... i imagine there must be some way to achieve the equivalent effect with bananas?

re 15v: it won't make a difference in theory, in practice i imagine the 7805 might get rather hot, ie when powering the thing entirely from your 15v psu. what i've been doing so far is to power the rpi separately (via micro usb/wall wart), so it's really only the op amps that need +/- 12v. so that will work.

i still have to try, but there's jumpers on the board that will allow you to either power the entire thing from the rails or else, attach a suitable 9v wall wart to power the rpi (the 7805), which i figured will make it easier to put everything in a rack as you'd be able to use regular power jacks rather than some usb feed-through contraption.

[loopt]

Very nice project.

Would it be difficult to do something similar but ditching the audio side of things while adding dc-coupled CV and trigger outs?

I'm more interested in using the raspi as a sequencing/triggering/modulation device with input from the modular side.

Cheers,
Thomas

[jdev]

Nice project! Thanks for sharing.

[bananeurysm]

Killer project! I wonder if you're planning on posting Eagle files (or files from whatever cad package you use) for this? I'd love to build one (or two!) for myself in another format. (Either 4u or 5u)