Help with code for fade loop

[blh64]

The TIP120 will drop a lot of voltage across which doesn't leave much for your light bulb.

difference between a tip120 and mosfet

hello, i just want to strobe an array of around 360 little LEDs all hooked together. They turn on and strobe fine with a 12V, 5amp wall wort. I've been using a TIP120 to strobe them from my arduino. Is this okay? Should I be using a mosfet? What's the difference really? thanks!

Those bulbs don't draw a lot of current so a single transistor should work.