gaudilabs/openthereminv4

Open Source Theremin Instrument

openthereminv4's Issues

characteristics

what are the characteristics ?

Volume ist crcking or bounceing

I hear a cracking sound when I mute or unmute the sound and when I increase the volume with the antenna. It is at the point where the volume increases.

No output through usb serial

I'm trying to connect my v4 through usb serial but I'm not getting any data from the theremin.

I am sure about "/dev/ttyUSB0" because it's the only available port. It's also doesn't show anything when I use ttymidi. What am I doing wrong?

Missing technical drawing

Hey, it would be amazing if you could add the scamatics aka the position of all the knobs and so on as a pdf, because I want to make a Kase with a midi output for the teremin. I could mesaure it but I think it would be better if I had the korrekt positions :).

If it is not possible that is also ok, but it would be a nice to have for the case design :)

greetings nice project

More flexibility on USB/Serial interface design could be nice

Hello Urs,

I had a look at this new theremin schematic. It is a very nice idea to merge arduino and schield board in a single one.

I hope that I don't bother you in a too much early or too much late stage of the development, I have just one comment:

As CH340G can't be re-programmed into a MIDI USB port, in order to allow implementation of some additionnal material for a MIDI interface (MIDI DIN connector, ... ), an additionnal free solder pad on TXD could be very nice to have.

Regards

Problem with a capacitor in the BOM

Hi,
I think there's maybe a mistake in the BOM
On line 31, for "C15,C16,C17,C18,C19,C31,C34", it's written both "22pF 16 V X7R 5%" and "MUST BE C0G (NP0)"
Thanks a lot for your work !

Dynamic wavetable generation

Instead to limit the number of wavetable due to max memory size, we could generate those wavetables on the fly and therefor have more options. This could even allow us to morph with the wavetables.

So, the idea would be to store the formula to generate the wavetable in the firmware and have dedicated space for the LUT. When the user want to change of wavetable, the content of the LUT would then be calculate on the fly (it might take a fraction of second). With this method we could have much more waveform to play with.
And we could even go more far, by using smaller wavetables, maybe 256 instead of 1024, and then have a set of generated wavetables to morph between them.

I wish, I could implement it, but I have some project to finish... Maybe one day, if I didn't sold my theremin before :p

Actually, one improvement for the v5, would be to be able to load wavetables from an SD card. "esp audio kit" could make big part of the job for you, DAC, SD card... are already built-in and would need to create a shield for the body sensing part, the few pots and CV output. Also, by having the audio input, you could imagine to use theremin to apply effect to a sound, e.g. a low pass filter.

SPI bus breakout

Hi,
Is there a place where one can plug onto the SPI bus?
Looking at the PCB layout in KiCAD I can't find a practical place where I could connect something.
I'm looking to add Bluetooth functionality so I thought I would add a secondary board with an ESP32 and a small screen to be able to connect to headphones/speakers and establish an A2DP stream.
Is there a better way to connect the two than soldering a wire onto the atmega's pads?
Best regards

Trouble uploading sketch from Arduino IDE

I'm trying to upload a new version to the theremin I just received last week (I'm trying the MIDI implementation, but this issue also occurs if I try to upload the standard version as in this repo), and I'm getting the following error message.

Sketch uses 27082 bytes (83%) of program storage space. Maximum is 32256 bytes.
Global variables use 362 bytes (17%) of dynamic memory, leaving 1686 bytes for local variables. Maximum is 2048 bytes.
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x00
Failed uploading: uploading error: exit status 1

I am selecting Arduino Uno from the boards list in the IDE, and as far as I am aware a "Programmer" does not need to be selected/the programmer choice doesn't matter in this case.

I have updated to the latest version of the IDE, I have tried multiple USB cables and ports, and I've searched for general solutions to this avrdude error, and nothing fixes the issue. Do I need to burn a new bootloader or something? I'm not sure exactly what the process looks like if so.

Any assistance would be appreciated!

Edit: for what it's worth, I just tried a calibration while I had the theremin connected to my computer via USB, and I had the Arduino serial monitor open and I saw the calibration details coming across.

ATmega fuses setting

Hello,
is known the correct setting of ATmega fuses? It would be useful to describe it somewhere.

Thank you