Open Theremin V4 with MIDI

This is just to inform you that Open Theremin V4 with MIDI is in Beta state and I am considering delivering official V1.0 in a few days.

I recently had opportunity to test the Open Theremin V4 (very nice !) and could finalize my implementation of the MIDI feature.

I merged recent evolutions from Thierry.

Don't hesitate to have a look at the Github repository.

Any feedback is welcome :-)

V4, but still uses slow ancient 8-bit MCU.

Yes, it is basically a merge of OTv3 shield and arduino uno in a single board. This let some I/O port on the MCU to manage a complete set of CV/Gate outputs. And now you can add a MIDI interface to V4.

Of course, it is an entry level instrument, but for the price you have have a prety good linear theremin that can control some analog or digital synths in an Euro-rack form factor. It opens the field for extensions... (e.g. Open Theremin + Oscillator module + filter module)

It is in V1.0 !

Just the begining of the story and a base for improvement...

Just a few words to say that I removed all calculation in float 32 bits from my MIDI code and replaced it by proper fixed point mathematics.

If you want to have a look.

Thanks to Crisbei and Dewster for help and encouragement

And I did the same change for Open Theremin V3 with MIDI.

Has anyone wired a V3 board to a NANO instead of an UNO and run V4 firmware ?

Not so much aware about arduino nano and would need to consider how you bridged your V3 shield to it but...

V3 and V4 have different connection to I/O pins. These hardware differences are reflected in the firmware.
Then V4 firmware won't work on V3 hardware and the opposit is also true.

But I don't catch the point of doing so... V3 and V4 firmware are both up to date at an equivalent level.

I have done it and it works. Except for the DAC for the CV's the hardware is similar enough. The problem is that there is "jitter" in both the volume and pitch and I am wondering if it is a compatibility issue. It seems that the 3.3v line is randomly being loaded down. Maybe one of the IC's is loading the power down. Tough to troubleshoot SMT especially since the Theremin works as it should except for the jitter. 

I understand that you spoted the differences. 
When developping MIDI firmware for V4 I also enumarated them and found that A2 and A3 pots, gate and cv were connected differently. 

Provided that you made appropriate connections, I see no obvious reason that V4 software should not work.