Arduino power question

I'm looking to control two motors with two SN754410 H-bridges. The motors have an external power source and the Arduino is powered by a 5 volt input. Is it possible to power both the chips and the Arduino on 5 volts without a problem?

No, the current surges into the motors usually cause problems for the logic in the microcontroller. Way better to keep them seperated.

CrossRoads: No, the current surges into the motors usually cause problems for the logic in the microcontroller. Way better to keep them seperated.

Ok, thanks. How does the current surge through the motors affect the voltage drawn by the logic portion of the bridge?

Motor current surges represent really nasty electrical noise that gets propagated onto every electronic device
in the proximity. If the same battery is used for logic and motors, this noise appears on the voltage feeding
into the logic ckts. And even with separate batteries, there still may be noise problems due to electromagnetic
radiation [ie, propagated like radio signals].