DRV8825 problems

I recently received my DRV8825, and hooked it into my old A4988 setup (A4988 problems), and it works… sort of. When I power up the system, I can hear when the motor coils are powered, but that seems to cut out every so often. When powered, I cannot turn the motor shaft with my fingers, but when it cycles off, I can. I thought I may have had flaky connections between the stepper and the motor so I double checked that they were good, solid connections. After more testing, I realized that the motor seemed to be cutting in and out at reliable cycles. So I watched the time. Sure enough, if I set a slower step (step every half second), The motor will cycle on for 3-4 seconds (during which time it steps), then cycle off for 10-11 seconds (during which time I can turn the shaft with my fingers) this process seems to repeat forever. I tried setting a faster step rate (step every tenth of a second), and with that, it will step for about a second, then it won’t cycle back on again (or I was too impatient to wait for it to, but I did wait a good minute or more). I have gone through and checked voltages for VMOT and VDD, and those are not cutting out. Why does the driver seem to be shutting off? It states that the driver will burn you long before it overheats - with my temperature gun I get readings around (and over) 130F. Is this normal?


It sounds like your driver is overheating. What do you have the current limit set to? What is the rated current for your stepper motor?

- Ben