Hi everyone. I'm a complete newbie to this forum thing as far as posting goes but I've got a lot of info from this site in the past few months.
I've started to design a CNC machine from scratch to fit the EMC2 software specifically. I have already made an opto-isolated BOB for parallel interfacing and now I'm working on a Bi-polar stepper driver using Allegro's A3982 stepper driver.
Now I've taken the reprap driver schematic as a starting base but ended altering 95% of the design after I knew what I was doing... HOWEVER I've run into some unsure areas as to what the better option would be.
I included the schematic. First of all my question is about pin 14 ROSC that controls the tOFF. I can't get my thumb on how to figure out what would be a better way to go. Over 3V it defaults to 30us so I can tie it directly to my logic voltage supply or I can connect it to GND with a resistor. But what does this really do? How will it benefit me from one to the other and would it make sense to throw a trim pot in there for fine tuning?