Bushman wrote ...

Thanks Eric, I am using the Mini MIDI/DR controller from Paul Slawinski which does the job. Then between the computer and the controller I have the dreaded USB cable Trying to picture your setup and how it is different from what I am doing?

Hydron wrote ...

The specific issue with these midi controllers is likely due to poor design, so there are probably other solutions too, but Eric's looks like a particularly classy way to do it.

Note that MIDI inputs should be opto-isolated (no gavlanic connection for either ground or signal) by specification, so no ground loops or anything - the USB-MIDI converter should be able to deal with EMI by clamping any induced voltages, but probably doesn't cos it's cheap chinese made garbage. If done inside the equipment like Eric's then you don't need to worry about any of this, as it doesn't pick up anything anyway.

USB is only mostly differential by the way, there are single ended reset and end-of-packet states (both lines low, see , but when done well should be okay as long as it doesn't get too close. USB definitely causes issues in some circumstances, and is nowhere near as EMI immune as stuff like ethernet, so should always be regarded as suspect when things aren't behaving as expected around a tesla coil.

Edit: Looks like nice work Eric! Looking forward to having a look at the design if/when you release it.

Graham Armitage wrote ...

I wanted to resurrect this thread as I was still having trouble with the nasty USB MIDI problem. I figured that sending the MIDI signal over ethernet would solve that problem. So I thought I would give it a try. The core of the solution is an ethernet shield on an arduino microprocessor. I hooked up an old wireless router that the arduino connected to via a patch cable. The laptop plays the midi signal via an rtpMIDI port (a virtual ethernet port) that is then sent wireless to the router. So no physical connection between laptop and MIDI controllers.

The arduino code is essentially running AppleMIDI library and when it sees a noteOn command I output the same note to the MIDI port which connects to the regular MIDI controller. Same for a noteOff. Essentially passing the ethernet MIDI stream from the laptop to the hardwired MIDI port. It allows me to run the laptop from anywhere safe via the wifi. There may be more elegant ways to do this, but it works and has eliminated my hanging note problem from the USB connection. Total cost was for an Arduino, ethernet shield, aluminum project box and some LEDs. Code was pretty simple.

One cool benefit is that now I can theoretically operate the coil from anywhere on the LAN, or open it up and play from anywhere in the world More geeky than practical.

Hope this provides an alternative to anyone else experiencing similar problems with the USB-MIDI.