Driving a SY20STH30-0604A from T249. Basic operation seems ok, but it’s not rock solid.
Controlling using Arduino via UART & TIC library.
Current limit set to 600mA (when stepping), dropped back to 100mA when idle. I give it a few ms to settle after requesting the ‘run’ current.
Vin is 12V.
When I’m stepping one step at a time, I don’t notice dropped steps. But if I set a home position, step away from home, then drive back the same number of steps (set target pos to 0), it mostly doesn’t reach home. It rattles a bit occasionally which sounds like it tried to step but didn’t succeed.
When scoping the coil voltage it looks a whole lot like the 12V is modulated, so current limiting is not ‘smooth’ like with a buck SMPS. My suspicion is that steps are happening in the middle of a modulation ‘low’ and therefore getting missed, but it’s hard to verify that. I also guess that somebody would have encountered this and therefore probably synchronised the 2, but you can’t always assume these things.
Any thoughts before I dig too much deeper? It’s so close to being great, but not quite over the line.
Thanks in advance.