Signalling voltage question

[Alan Anderson]

Originally Posted by JBotAlan

Now, the way I understand it, the OI's port is a standard RS-232 port. That would imply it is signalling at, like, +/- 12 volts, wouldn't it?

The RS-232 specification says valid signals are anywhere from +/- 3 to +/- 12.

The port on the Visor demands 3.3v, and I think that's a maximum, not a minimum.

I don't believe the Visor does standard RS-232 by itself. It needs external hardware (in a serial cradle or cable) to convert the levels on its connector.

Is there an easy way, other than trying to track down a serial dock, to do the hardware interface here?...EDIT2: Ohh! I could just use a MAX232 couldn't I?

A MAX203 would require fewer external parts. Look here for a relevant project.