Newbie question here: I will be using an arduino pro mini 5V powered with a 9V battery.
I'm making an LED chaser, so there will be LED only (around 30).
As I'm about to order the LEDS SMD and the resistors I need to determine the resistors value, and here comes my question:
I found the technical specs which state the arduino pro mini can be powered from 5V to 12V through the RAW pin as there is a voltage regulator, so if I use a 9V battery the output will still be 5V out of I/O pins ?
(so basicaly do I use 5 or 9V to calculate my resistance value)