I'd like to build an USB - TTL converter for my camera. I've seen on FTDI site many options but I don't know which one to use, some of them are USB - SERIAL converters.
I have an ideea to use one of these schematics to build USB - SERIAL converter, then an level shifter with MAX232, then use optocouplers to output safely TTL.
I have also a question: If I build this converter, it is necessary to add the optocouplers? Is there any chance to have the surge problem, spike, lightning and grounding problems if I don't use the optocouplers?
Below is the schematics for the converter SERIAL - TTL, opticaly isolated, which needs power supply. I am trying to get power for this converter from a USB - SERIAL converter.
Can this be done?
THANKS