Grids + Shruthi's?

Hello everyone :slight_smile:

I’m very new to modular stuff, but I fell in love with Mutable Instruments, so I’d love to get started with MI’s modules.
I’m currently building 3 Shruthi’s (YM, 4MP & Polyvoks) and have been wondering : can I use them with Grids ?
I would of course mod the Shruthi’s to add CVs, but is that doable ?
How should I go about it ?

Any input is appreciated.

Bad idea. You’ll need three Shruthi to play the 3 channel of sounds, and you’ll have to mod them to get trigger by an external gate.

Yes, pichenettes, I know I need 3 Shruthi’s and I need to mod them, that’s exactly what I have and want.

Why is that a bad idea ?

Modding would just consist in soldering 2 mini jack female to the control board PCB of each Shruthi’s, no big deal, is it ? I guess Grids outputs no more than 5v ?

I’m fairly certain that it is a bad idea because the shruthi is digitally controlled, not voltage controlled.
Simply adding female jacks to the board and powering 5-10v trough them would guarantee a non-working shruthi.
Edit - there is a mod for this sort of thing on the wiki, but I wont link directly to it, since you seem to lack a bit of the technical know-how of how to do it properly… (Messing it up= destroyed ATMega = ~12$ out the window+having to program a new one/order one from pichenettes)

The shruthis were never meant to be controlled via actual CV, unlike for instance the Anushri.

You’re making lots of assumptions, there, my friend.

The specs of Grids specify it outputs 5V for the trigger and accent 1,2,3.
In the Shruthi docs, in case of CV mod, it says it supports 5v.
I don’t see what the big trouble it would be.
It’s just a trigger and an accent, I’m not trying to insert CVs in the chain.

BTW, I’m old enough to run the risk of destroying an ATMega, thank you for your concern.
I also can find a mod in the wiki/docs, even if you don’t link it directly.

And we’re here to push the boundaries of what’s “meant to be”, aren’t we ?

If I think it’s a worthwhile use of my time and money, who’s to argue against it ?
I’m merely asking for technical advice, not to be judged.

Thank you for your understanding.

i don’t think anybody was judging you.

how do you plan on controling the pitch?

it may be a good idea to build some 3 channels cv 2 midi converter then. This way you can control the pitch more accurately, perhaps with some simple interface like a screen and an encoder.
Maybe you can even mod a midipal for that purpose (provided you buffer the inputs using some CMOS logic thingie, or simply voltage dividers, since the midipal is working under 3.3v)

Sorry if I seemed judgemental, that wasn’t my intent, please do try the mod, and report back what you think of it.

For some it’s just a massive hassle to have to get another ATMega, others have several they just use just as decorations…

Anyhow, nobody tells you that you can’t do it, so by all means, go ahead, you do seem to know both the implications, and how to do it, please share a video of how well it works when done? :slight_smile:

if you had a triple trigger to midi converter (like fcd72) it would be the easiest way but i guess there’s still no direct controlling pitch that way, just note ons/offs
@fcd72 what about the 3x trigger to midi converter?

> Modding would just consist in soldering 2 mini jack female to the control board PCB of each Shruthi’s, no big deal, is it ?

Modding would consist in:

  • modifying the firmware so that the notes (which ones - you’ll probably have to make it possible to explicitely set a note) can be triggered by a trigger received on the “CV inputs”.
  • many optimizations and system level tweaks to make the timing acceptable (the Shruthi “CV inputs” are very slow).

Building fcd72’s tool would indeed be a better use of your time…

You mean Blinky?

Which module do you want first? Im currently shifting the RED LFO to an INFRARED LFO thats even more red :wink: because i feel many more of you need some LFOs . . .

For quick and cheap and dirty you could evilBay an Alesis D4 or D5 for trigger to MIDI.

If your Grids out is 5.0V and your Shruthis ATMega is powered with 4.9V, guess what happens…
The CV ins are directly connected to the ATMega, and nasty spikes from the Modular (and we all know modulars produce all kinds of nasty things on PowerRails) may instantly go over the 5.0V Limit when plugging in. I highly suggest protecting the Inputs with a 1M or less R and use a 4.something Zener Diode before even thinking of connecting it to anything else than a Voltage divider powered by Shruthis own PowerRails. Trust me, i know what im talking about. Only thing then left is rewriting/altering the Firmware…

Thanks guys, it’s much clearer now.
Indeed, I’m definitely not looking to hack the firmware just for that.

What I’ve been looking for is a trigger to MIDI convertor, like rosch suggested, and like Frank built… Love the fish, BTW, big Futurama fan here :wink:
You have a microcontroller there, don’t you ?

I was just thinking about using Grids as a weird triphonic sequencer…

Its a PicAxe 28x2, get one (+ developer kit) and do it on your own, its a great learning experience. You can build it on perfboard and code the Firmware in one weekend if you already have basic Programming skills.

I have a bunch of RBB Arduino boards (Real Bare Bones, small footprint), would that be good enough ?

I have no clue of Arduino…

For this youll need 3 hardware Interrupt Pins for the 3 Triggers and a Hardware Serial Out Port for the MIDI. You might get away with one Hardware Interrupt Pin and 3 Diodes, if your Arduino is quick…Check if your Arduinos have that. If so you are good to go.

i think only leonardo and mega ([edit:] and due) arduinos have more than 2 of those according to that

… everything else should be realy easy with arduino as there is already a finished midi library.

thinking about it, picaxe might be cheaper. and with the arduino there is kind of an overhead. you could just build a grids-like device on its own with it.

i have spent some time with arduino and picaxe (after fcd72 convinced me) and in my experience both are equally simple to get stuff working with.

Heres the Sourcecode for Blinky, the inputs are triggered by bare 3904 inverters for protection, for the MIDI out, just use the same Circuit as the Shruhti.

Thanks, the PicAxe 28x2 seems like fun, I think I’ll give it a try :slight_smile:

Just for the sake of completeness, is Blinky kind of the same as a Doepfer A-192-2 Dual CV/Gate to Midi/USB Interface ? (

i think blinky is just 3x gate/trigger to midi (no cv)

would be nice if more shruthizen go picaxe.
at the moment it’s only fcd72 and me i think :slight_smile: