Chagrin:
mcreefer:
Also in the bildr guide connects the source to the gnd pin on the arduino. Could I ground to something else? I would think that grounding them all to the arduino gnd would be a bad idea.The tutorial is just showing that the external power supply (0-60V) is connecting its ground with the Arduino's. Whenever you use multiple power supplies the grounds must be connected so everybody agrees on what 0V is. If you're only using a single power supply then this is not necessary.
Good point. I'll be using one driver for all the leds. Each led is 5-10W so they pack a punch. Also (2) 20W leds.