ghlawrence2000:
Perhaps it would be better to say "The 'older' arduino shields expect / 5 volt" as there are now more 3.3V Arduinos than 5V and well designed shields adapt accordingly, but your point about level conversion is valid.G
Cheers, edited accordingly...
On my due, I designed an optically isolated motor control system before I found the 'level shifter' circuit.. was a bit paranoid about frying my Due so wanted to make sure there was no way the motor circuit could ever possibly back feed into the MCU.
I did buy some level shifters and use them for GPIO, just not for motor control at this stage...