# Max voltage on input pins?

Hello i was wondering what is the max input voltage on a arduino uno 328p? I'm trying to monitor a 12v dc and 5v dc my target is 2.5v what i came up with is a 19k and a 5k resistors for the 12v and 2 of the 5k resistors for the 5v using a Voltage Divider website to help. also maybe monitoring 3.3v so was looking at that and maybe 2 of the 3k resistors for that or two more of the 5k resistors? not sure on that yet can someone confirm is I'm okay with all this or am i off? thank you.

Hello i was wondering what is the max input voltage on a arduino uno 328p?

Supply voltage plus half a volt.

i was wondering what is the max input voltage on a arduino uno 328p?

It is the value of the supply to the processor chip (usually 5V) plus 0.5V. After that things get damagie.

power supply puts out is 12v well comes up as 12.08v the 5v comes up as 5.12v the 3v comes up as 3.34v the target is for the 12v at 2.5v the 5v is target at 2.5v and if maybe i add the 3.3v the target is for 1.5 to 1.8v.

power supply puts out is 12v well comes up as 12.08v

Irrelevant. There is a regulator on the arduino.

the 5v comes up as 5.12v the 3v comes up as 3.34v

It might but do not base any calculations on that.

the target is for the 12v at 2.5v the 5v is target at 2.5v and if maybe i add the 3.3v the target is for 1.5 to 1.8v.

Sorry no idea what you mean by these words.

i have tested the 12v with the 19k resistor and a 5k and got a 2.5v out of it now testing out the 5v with two 5k resistors see how the voltage comes out before i plug a arduino in. i think the 12v is right on the money :)

with the 19k resistor

That is a very non standard value is it not? As is a 5K resistor.

Are these values measured?