Setting up a analog port on a chip up system ?

Hello

I am working on transferring my fully configured project from a Seeeduino to a minimum board / on bread board at this time.
My project uses an analog port with a 47k and 100k resistor to work as a voltage divider to determine the state of a 12 volt battery.

Ive programmed my chip and fuses etc, and transfer the sketch. All looks to be working, but dont think I`ve sent up the analog part to fully match the results of the Seeeduino.

I have left the vref pin floating and not added other components other than the crystal and caps , other than the resistor for the reset that is.

To get the same result (0 – 5 volts ) as my Seeeduino should I be added vref to the -5 volt line and adding more components ?

OR , is the vref internal and set up by the programmer ?

Should work the same with nothing added to the analog reference pin unless you were adding something to the analog reference pin on your Seeeduino. Selection of analog reference source is under software control.

Lefty

Thanks , the oops Aref is unconnected on both.

"Selection of analog reference source is under software control."

I think the Aref is set with a lower voltage level , when I was installing the bootlloader and fuses etc, I didn`t know what I was doing so went with default other than the ones I was told to change.

Now I think I`m a little wiser on what each fuse setting is about.