> I've got a gumstix/roboaudiostix combination working (thanks to all the help
> from this list) and I want to use the robostix to drive motors and receive
> sensor data. My electronics knowledge isn't great and I would like to build
> a protection board for the robostix in case I accidently feed it the
> incorrect voltage or too much current etc. Do I only need zener diodes to
> limit the voltage and resistors to limit the current? Also, does the board
> have any built-in protection? Any advice on what I need would be greatly
There isn't any builtin circuitry to prevent that type of problem
(hooking up to high a voltage).
Personally, I tend to use buffer chips, although these generally only
work when you have unidirectional signals.
Having an inline resistor is definitely a good idea. I've never used
zener diodes like you suggested, so I don't know how good/bad they
For the ultimate protection you can use opto-isolators. You just need
to be careful of the speed rating. Some are quite slow.
Vancouver, BC, Canada