My arduino diecimilla is giving 10V at the 5v output, and also 6,6v at 3,3v output. Anyone had that problem before? is the first time I used it and I'm powering it with 12v DC... it also happens when USB powered.
Any idea? how to solve it?
If you are reading 10 volts when powered from USB then you probably have a faulty volt meter.
If your sketches are functioning correctly then you almost certainly don't have much more than 5 volts powering the ATmega168 chip.
Try measuring a 1.5 volt battery with your meter and see what that reads.
Thanks, I'll try, I hope it's just voltmeter