Impact of microstepping on stepper motor

Hi

I'm operating a NEMA 17 stepper motor through Matlab 2014b , arduino Uno R3 with Arduino IDE 1.8.5 using adafruit motor shield V2:

a = arduino ('COM4', 'Uno', 'Libraries', 'Adafruit\MotorShieldV2');
av = readVoltage(a,3);
shield = addon(a, 'Adafruit\MotorShieldV2');

The motor has to do a 180° rotation in three portions:

myMotor.RPM = 3;
move(myMotor, 18);
pause(.01);
% checking keyboard input
move(myMotor, 71);
pause(.01);
% checking keyboard input
move(myMotor, 17);

The duration of the rotation is about 12 secs. However, to smooth the rotational movement, I introduced microstepping:

myMotor = shied.stepper(2,200, 'RPM',10, 'stepType', 'Microstep');

Now the same rotation takes 17 secs on average. Has anyone an idea why this happens? Could this be due to microstepping reducing torque by 30% compared to full stepping? As my knowledge about motor functions is very, very limited, I'd really appreciate some help.

[barath V]

hi i see that 71+17+18 is 106.and 1.8*106 gives 190.8 degree it isnt 180 degree.

in microstepping were u able to move the motor less that 1.8 degree per step.pls shrare if you know how to do it.