Will I damage a GPIO (set to input) if introduced to 10V 1mA? I read somewhere that the GPIO ports can tolerate maximum of 16mA
I need to detect
0V ). Could I possibly use voltage divider?
The 1mA is not a problem, but the 10V is a problem. Like you suggested correctly yourself, a simple voltage divider using a couple of resistors will do the job.
If you make R1 1k and R2 470 Ohm, you should get a nice 3.2v on the output with an input of 10v. If the 1mA is a hard constraint, multiply all resistor values by 10, because using the given resistor values this divider will dissipate 6.8mA on the 10V side.