If we are talking about the THB6560AH, then according to the datasheet it has a logic threshold of 2V, so you shouldn't need a level converter BUT the circuit for that driver board [www.massmind.org] has pullups to 5V on the control lines. I'm not sure why, because the ENABLE is active high, and there are internal pull downs in the chip. Perhaps some control boards use open collector outputs? If you removed those pullup resistors, you would not need level conversion. Ah, that might be difficult they are in resistor networks :(. That board is not designed to be 3.3V friendly!
Also the min step pulse is 2.3us, so that would be easy to do in firmware, some firmwares support this already.
I was planning to design some header boards to make it easier to connect external drivers, if I remember I'll do some next time I order some PCBs. It would be easy to do with piece of stripboard of course.
I'm not sure whether servos will require a level conversion or not, reminds me I should test that :)
Also the min step pulse is 2.3us, so that would be easy to do in firmware, some firmwares support this already.
I was planning to design some header boards to make it easier to connect external drivers, if I remember I'll do some next time I order some PCBs. It would be easy to do with piece of stripboard of course.
I'm not sure whether servos will require a level conversion or not, reminds me I should test that :)