Measure time a key is pressed down?

Hello!

Do anyone know a simple program, a website, or perhaps a simple AutoIt script to achieve the following:

When i press [Enter], ".", or any othey key, I want to see for how long that specific key is pressed down. This should generally be a very low number, a few milliseconds perhaps. I want to measure this with precision.

Later on I want to measure mouse clicks as well (down time), but I'd love to start look at keyboard data.

Thanks in advance!