Can you not have a 5v rail and 24v rail? Then and measure both with separate analogInputs
Have you started building this yet?
Why are you using 120vac to 12vdc to 5vdc?Does the 12vdc power anything else?
Why is there a 0 to 5 need along with a 5 to 24?
Since you haven't provided a schematic, I will draw one when I get home from work.
I'm not. I'm using 120VAC to 12V to power the Arduino and some analog circuitry. Not sure where you got the 12V was converting to 5V.Because the system is designed to test battery packs of 1 to 20 cells (1.2V through 24V)Schematic of the section in question is not that complicated. It consists of a SPDT relay. COM to ADC, NO center of resistor divider, NC to top of resistor divider. (NO for >5V, NC for <5V). Battery to be tested connects across the resistor divider.That's all folks.
I was thinking 12 was converting to 5 on the Arduino's on board regulator.