1) If arduino is NOT plugged into 5V. The Vcc will be ~3.5V. ...2) If arduino IS plugged into 5V. The VCC will be +5V or so. ...
Then his idea might work?
Quote from: sbright33 on Sep 12, 2013, 04:16 amThen his idea might work?No, as I was trying to explain. analogRead doesn't return 750 from Vcc, if Vcc is 3.7V, it returns 1023. Same as if Vcc is 5V. The number 1023 is returned if the analog pin is equal to the Vcc pin. Thus, on its own, you cannot work out what Vcc is.Unless you use an external reference or the internal 1.1V reference.
VCC is (roughly) 3.5V and battery+ is 3.7V.