I'm working on a project that requires making a fairly universal board (to work on different model machines). I need to hook up many pre existing motors and switches/sensors to the board that all work off of different voltages and have their own unique pin/plug configuration. I figured using fpga would allow programming of the correct configuration, but I need the 3.3v fpga pins to accept input/output from 5vdc, 12vdc, and 24vdc selectively. Is there any simple solution out there? They all need pwm capability, and the ability to drive small motors/devices.
I have thought of using load switches for the outputs, which seems correct. As for inputs, I was thinking isolators, but they don't allow such a wide range of input voltages if I am correct. The only other thing I can think of is voltage regulators in series or parallel to convert the voltage to 3.3v logic. However this may pose a problem where pins can not be ground (as in 0v) for high current as well as serve as a logic input. Any help or ideas would be appreciated.