I have a Pro Mini running off 3xAA (3 x 1.5V) alkaline batteries. I want to measure the voltage of the batteries.
From those two threads I understand I can determine the battery voltage by feeding the supply voltage into one of the analog pins.
However, I have a question - is there any benefit to be gained in how the connections are made and in when the battery measuring code is run.
So, comparatively speaking, which scenario would have the least amount of battery drain due to voltage measurement :
- Battery connected direct to A0 and a sketch + battery measuring code running every second.
- Battery connected direct to A0 and a sketch running every second with battery measuring code running every 24 hours.
- An output pin (pulled high by battery measuring code) connected to A0 and a sketch running every second with battery measuring code running every 24 hours.
Option 3 also begs the question - is this a viable approach?