Is it possible to Power up Fez Hydra trough RS232 port. I am looking for Red(power) Rs232 module.
I think there is voltage difference, how can we over come with this? (if module is not available)
Scenario, i don’t want extra power cable running into device. If I recall old Rs232 mouse has same functionality (draw power from RS232).
You are not going to get sufficient current, through an RS-232 interface, to power a Hydra or any other FEZ board. Only enough power for a mouse.
There is no explicit voltage pin in an RS232 connector standards, and as Mike says you are only getting “signal” level power from the signal pins, so you can’t really achieve what you want using as-is components.
If you look at the signal on an RS232, it’s in the order of + and - 12-15V (although modern devices rarely go to that level, I expect most to operate in the ~6v range). So it would be non-trivial to provide a few hundred milliamps from that, reliably, to allow a processor to work.