One design goal I have for this project is to make it a standalone intrument, meaning tha you don't need to connect more cables than the audio cable to the amp, to play with it. The only thing missing to get there is an integrated battery. But for now, I focus on optimizing the powering over the RJ45 cable, since this has to work also and should be used to charge the battery too.

Troubleshooting power

Some of the actuators demand quite a lot of power when heavily used.

One Led needs up to 60mA and if all 102 leds light fully up the fretboard alone needs about 6 Amps at absolute maximum. But I currently use them in half brightness which is still well enough, even in bright light. I haven had a situation yet, where it draws more than 1.5 Amps.

The KickUp is fed with 12V which are supplied via a dc-converter. The overall power consumtion of the KickUp isn't high, because each solenoid is only active for max. 5 milli seconds. But they produce heavy current peaks, especially when they all become active at the same time.

Those circumstances can lead to commnication problems as power goes through the same cable as the communication lines (induction), or worse, make the microcontrollers freeze.

So there is still some work to design a proper power concept. Here are some thoughs on this. If you have advice for me, Id' be glad if you'post the in the comments!

1) Higher Voltage

Maybe I should let go the idea to power this whole thing with 5 Volts and go much higher, like 48V, as power over ethernet does (PoE) for example. This would reduce the needed current dramatically. Various dc-converters could be used to power the different loads.

2) Super (Bypass-)Capacitors

I allready have experimented with a 5.5V, 1 Fahrrad bypass-capacitors on the KickUp (before the dc-converter) with mixed results. There are some side effects to deal with, like the fast charging rate when plugged to power and the long discharging time when the guitar is switched off.

3) Heavy lifting via Battery only

Maybe I ditch the idea of powering the whole thing via those tiny wires of the cable (although I use two of them per pole) and make an energy saving mode where certain function only work when the battery is charged. Initially I wanted to use a beefy single cell LiPo to make the charging easier, but a higher Voltage three cell one npw seems to be more adequate to me.

As a momentary solution I went over to power the KickUp exclusively via a separate externally charged 3-cell LiPo and power the rest with the 5V comming through the cable, which works, but isn't rellay elegant