Music Emulation on Spark Max/Neo?

Anyone know where my team should start looking for music emulation on the Spark Max/Neo? Looking to play Detroit Rock City and make a musical demo bot. Thanks! Yes, this is a real request for help and not a troll, we really do want to play KISS songs.

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Relatedly, any electronic tinkerers who want to come up with a way to transmit the BLDC square wave into a standard guitar cable so we can run it through a Marshall amp stack?

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Maybe a voltage divider to bring the 12V to “instrument level”? I guess a transformer might also work since the signal’s effectively AC.

Hmmm, there may be a better way to do this but off the top of my head I would suggest making a list of speeds/voltages which will output certain notes from your motors using the Rev hardware client then programming that in a timed sequence. Make sure you listen to the song beforehand closely and turn any repeated sequences of notes into functions or loops, otherwise you’ll more than likely be spending most of your time repeating code.

Also, I’d highly suggest trying to make use of more than Neos for instrument variety if you can.

Guitar amps are expecting pretty low voltages. I would buy a microphone isolation transformer to solve your ground loop problems from the get-go. That’s what my son and I built into the vacuum tube amp to allow a phone input. Not the one we used, but similar. BTW, I actually used two of them; in series on the amp side. One primary for right, one for left. Since you are using PWM, use a series capacitor to block the DC!

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Would be neat to use the neo550 as well

I think you want the switching frequency to be the the frequency of the notes so with NEOs having 7 pole pairs you would want to set rpm to (audible) frequency * 60 / 7

for example, middle c (256hz) would be 256 * 60 / 7 ≈ 2194 RPM

I’d guess Falcon 500/FX does this in firmware, and that it is probably going to be hard to get good notes without firmware support. Obviously, just an opinion. Let us know how things go…

This sounds like a pretty useless project, but also a fun really one to work on. I’ll see if anyone on my team is interested to help me work on a library for this.

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Useless = fun

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Obviously Rev has to drop everything they are doing to work on this right now /s (I mean I’m not saying drop evvveeerryyy thing but would be cool)

Who wants to ping Greg…?

1…2…3…NOT IT!

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