- Are the resistors between digital pins & gates of transistors necessary?
- Are the source-gate resistors necessary?
- Would you use other MOSFETs/ resistors values?
- Is there a risk to damage nano over time with this circuit (reverse voltage / current)?
- Yes, but remove R2
- Yes
- Don't know, requires too much time to research. Do they work OK? If so they are probably OK.
- Not that I can see
I don't see any point to the double switching, just turn on and off the boost converter, unless you tried that and it caused a problem I cannot think of.
If the only thing the boost converter powers is the gong then you can switch its 0V input, no need for high side switching if what I said above about not double switching is OK.
You really should power the Nano from 5V not 12V, the on board regulator is crap. Use a buck converter.
++Karma; // For a nice clear first post with images properly included and clear questions.