I want to drive 4 seperate motors, the largest would be 7V 550 mA and about 1.2A stall. I intend using a pair of SN754410's. Power supply will be a good 7.2V. My question is, how safe is my Arduino Duemilanove board if I use the same 7.2V supply for the motors and the micro processor. Would it be a better design to have 2 seperate power supplies. I have room.