Grumpy_Mike:
If i want to use a LED that needs 20mA (i use to do it with arduino uno) there is risk (maybe is sure) to broke The board???
Yes, that is what a current limit means.
If you want 20mA then use a transistor.
Is required a particular bjt for example???
Arduino Du gives 3mA... If i use a classic 2N222?
Thanks for The answer 