Pololu - connect motor supply ground and logic supply ground Is it okay to directly connect together the grounds of the logic supply and the motor supply when using a Pololu style stepper driver?



If yes/no, why so?
That depends on how much noise you have on your motor power supply ground.  You definitely want the 100&nbsp;µF capacitor to have a good high frequency response.  Motors turning on and off can be noisy, and that noise can cause false clock signals in your logic circuitry if you tie the grounds together.