What happens if I use extarnal DC and USB at the s

Is it dangerous to connet the Arduino Decimila to the computer via USB while it get its power from external DC?

Cheers

Nope. The jumper isolates the power sources.
Probably not a good idea to short all three pins though.

I usually run mine off a power pack with USB plugged in.

Thanks :slight_smile:
This forum makes life so much easier :):):slight_smile: