Voltage divider help!

We are trying to make a voltage divider for our college’s robot. The objective is create voltage(already made) and use an arduino uno to measure when the battery drops from good,warning, dead. I have attached our code to this post. Any help would or pointers in the correct direction would help!

BatteryTester.ino (698 Bytes)

Do not double post.

Do not double post.

It's OK, I deleted all the others.

if ( voltage <= 0.04) //8v ??

What are the resistor values of your divider.

I expected to see someting like
if (voltage < 7.25) //8v