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Topic: Dual Midi Channels (Read 227 times) previous topic - next topic

satindas

Hi all,

I'm wondering if there's away to listen to two MIDI channels simultaneously using the Fortyseveneffects MIDI library.

 According to the docs for setInputChannel()
 ... "Valid values are 1 to 16, MIDI_CHANNEL_OMNI if you want to listen to all channels..."

The scenario is basically two analogue mono synths operating independently in a single box with a single MIDI input with each synth listening on separate, discrete channels.

I only need CV and Gate from each channel.. no PB or AT or CC etc.

 I'm kinda rubbish at this so any help would be hugely appreciated.

Cheers

Grumpy_Mike

Quote
I'm wondering if there's away to listen to two MIDI channels simultaneously using the Fortyseveneffects MIDI library.
But your question then goes on to say:-
Quote
The scenario is basically two analogue mono synths operating independently in a single box with a single MIDI input with each synth listening on separate, discrete channels.
So I make that is you want to send to two MIDI channels simultaneously not listen to them. And yes you can do that.

slipstick

I only need CV and Gate from each channel.. no PB or AT or CC etc.
Are you sure you're talking about MIDI? CV and Gate are not MIDI concepts. MIDI deals in Note numbers, On/Off and velocities. It's possible to do conversions to CV/Gate provided you know exactly which CV scheme you're dealing with but it's unusual (and Arduinos aren't exactly good at outputting accurate DC voltages).

Steve

satindas

#3
Dec 09, 2017, 10:45 pm Last Edit: Dec 09, 2017, 10:51 pm by satindas
Ok, maybe I wasn't very clear.

1x MIDI input > Arduino (listening on two channels) > 2 x DACs > 2x Analog synths (CV/Gate)

Each synth needs to respond to NOTEON /OFF and PITCH from independent MIDI channels.

Is that possible ?

P.S  When I said "I'm rubbish at this..." I meant coding/digital stuff. I've been using analogue modular synths for years. :D



Grumpy_Mike

Quote
Is that possible ?
Yes.

slipstick

Yes. That is not exactly difficult to do without even using a library.

But if you want to use MIDI.h just listen on all channels (i.e. MIDI_CHANNEL_OMNI), set up callback handlers for Note On/Off and in them put the equivalent of "if channel 1 send to DAC1,  if channel 2 send to DAC2 else do nothing".

Steve

satindas

Thanks Steve!
  One more question .... Would this be doable using the Attiny85.  From what I understand, by using the i2c bus for the two DAC >CVs  I should have enough pins for the two gates and the MIDI input. The ATT85 seems perfect with its internal clock and i2c but are there things I need to be aware of that might mean the ATT85 is not suitable?   I'm basically trying to keep the footprint as small as possible due to limited PCB space.


Grumpy_Mike

The ATtiny85 has no UART therefore it can not use serial communications. You will have to use software serial but the accuracy and stability of the internal oscillator might not be enough to get reliable MIDI communications.

satindas

#8
Dec 10, 2017, 03:57 pm Last Edit: Dec 10, 2017, 04:03 pm by satindas
Thanks Mike!

Hadn't realised that .

The Microchip product search seems to indicate that the ATT814 fits the bill nicely.

1xUART 1xSPI 1xI2C "accurate internal oscillator" and a DAC thrown in for good measure, which I'm sure I can find a use for.

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