I was working on a project which had a DC-DC boost converter (7.2V input, 24V output) running a A4988 stepper board. I managed to get it running, however, on my last test run, the A4988 failed. Also, when it failed, it shorted itself ENTIRELY, putting 24V into my Pi and destroying that too!
Has anybody else experienced anything similar? I had all the recommended precautions in place: a 25V, 100uF cap across the inputs 0.5cm away, the motor was plugged into the board, and the driver failed right in the middle of my program, when the stepper was already spinning at 50revs/sec.
I am sorry your A4988 and RPi were damaged. It looks like from your other post that you set a current limit of 2A; has that changed? Can you upload pictures and a wiring diagram that show how you had everything connected when the damage happened? Also, could you post close-up pictures of the driver?
By the way, the 25V capacitor you are using is not appropriate for suppressing LC voltage spikes from a 24V supply, which could have fluctuations that bring it over 25V. For that, I recommend using a 50V cap.
