BulldogLowell:
So, if I don't want to spend to much on a (multiple) MOS for this project, and I am only looking to pass less than 200mA through any one group of led's, the 2P2222 'old fashioned' transistor will be OK, yes?
Yes.
Also a lot cheaper/smaller.
Use a 220 Ohm resistor between Arduino and transistor base, just to be sure you're saturating it.
PS: MOSFETs are 'old fashioned', too. It's just a different way to do it. MOSFETs have problems all of their own.
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