New to this.
Have looked at hundreds of postings, but not found answer.
Building battery capacity tester/charger station.
Was having problem getting accurate voltage readings.
Come to find out internal voltage references were off.
5.0 vdc = 4.69 vdc and 1.1 vdc = 1.08 vdc.
No problem since i use external DVM to get these new voltages.
Have 10 more Nanos, and most have different voltages.
What i am looking for is a way to get actual internal voltages to use in equations, with out having to test each and every board i use. (Would be a pain if had to replace board and forgot to test volt and change code for each board used)