User Manual

Version 1.5 - December 11, 2010
10
Further if two different voltage sources (batteries or power supplies) are used, say one to
power the Arduino and one to power the MegaMoto, it is imperative that the connection
between the negative terminals of the voltage source be lower impedance than that between
the Arduino and the MegaMoto. This is to prevent a ground loop between the Arduino and
MegaMoto, which can destroy either unit. See Figure 7 for an illustration of this. If the
Arduino is powered by a USB connection it is not necessary to provide this negative-to-
negative connection as the USB ports are protected against such faults.
Figure 7. MegaMoto and Arduino connected to different batteries