Arduino Mega y pololu drv8825

Can you confirm:

  1. You have a wire between one of the Arduino GND pins and the GND connection (next to ¬FAULT) at the bottom right of the DRV8825 board;

  2. You have the other GND connection (the one next to VMOT) on the DRV8825 connected to the negative or common output from the 12V power supply?