But I have a 5v stepper motor and get the same results, sporadic rotations if any at all.
I guess the amps would be reduced, but by a very little amount.
My power source is a 16v 2.5 A, set up with a variable voyage regulator. And an Arduino Uno and a motor shield with 3 shift registers (74HC595N).Using 12v on the Nema 17 I get very sporadic results in rotation of the motor. The sketches are from the Arduino ide library. Any help would be appreciated, Thank you.