what Kind of Sensor that i can use to know how much angle stepper Motor shaft has rotated ? Actually,I am thinking to rotate my stepper Motor at 1 rpm and my stepper Motor shaft Diameter is 8mm and length would be around 20 mm. I am using this stepper Motor in very sensitive Case that is the reason why iam going to use microstepping Driver also. Can anyone help me out form this query? And ,Thanks in Advance.