WAIT ARDUINO-PICO HAS HAD SERIAL PRINTF THIS WHOLE TIME?!?!  WHEN DID THIS HAPPEN?!

I've been using hacks with the preprocessor and dozens of calls like Serial.print("V=");Serial.print(voltageStr);Serial.println(); this whole time!

Dang, wish I'd known that like, four months ago.   Anyway. 

Real quick update, completely overhauled the software, set it up to handle switching between modes make sense, and cut down the spaghetti code.  Well at least a little bit.  Also got most of the weird glitches out of doing large fonts with this display, I can now do 24 and 48 point fonts as well, which are at least closer to a usable size.  Might choose a different font in the future that's a little taller and narrower, but it works for now.  At this point working on making it more real-time so I can get sampling at a consistent frequency to be able to add a notch filter for 60Hz main, some more robust filtering in general, and AC measurement modes.

Here's the current hardware, I do need to cut down the thickness of this at some point, though it is about 1/2" thicker than originally designed - the switches I used for this were cheap ones off aliexpress, for a nicer rev 2 I plan to use some lower profile but more expensive ones.  That and the ADC and pico are mounted on female headers, so I need some additional depth for those.