RPM control of unipolar stepper motor (M42SP 6TG,4.7 degree) mistumi with atmega 8

[Magvitron]

Hi,
i am trying out a circuit and a code. The code works perfectly in Proteus simulation but in real world, the stepper motor movement is jerky and the RPM is too low for the application. my question is simple
How can I increase RPM of the motor.
I'm attaching everything I got here.
View attachment stamper.zip

 

[sky_123]

I don't have Proteus so unless you attach a jpg image, I cannot tell what was designed.

In any case, any simple home-built stepper motor driver will exhibit jerky behavior because that's what stepper motors do, unless you
can implement microstepping (which is complex, which is why a dedicated stepper motor controller is preferable instead of a general purpose
microcontroller).

 

[FvM]

Smooth stepper motor control in software requires interrupt based step timing and acceleration/deceleration ramps for higher speeds. I don't see any kind of appropriate stepper control in your code.

 

[Magvitron]

smoothness is not that much of an issue. All i want is to increase the RPM of the motor. I reduced the delay between the individual pulses but the rpm is constrained at 10 rpm or so.

 

[Magvitron]

hey got over the problem....
thanks fvm for the tip

ISR(TIMER0_OVF_vect)
{

switch (i)
{
	case 0:
	PORTB = 0b10101111;
	break;
	case 1:
	PORTB = 0b01101111;//-45*/
	break;
	case 2 :
	PORTB = 0b01011111;//-45*/
	break;
	case 3:
	PORTB = 0b10011111;//-45*/
	break;

}
i=i+1;
if(i==5)
 i=0;
//	PORTB = 0b00000000;//-45*/
}

 

[FvM]

i=i+1;
if(i==5)
 i=0;

Is inserting a pause. Should be if (i == 4) or simply

i = i+1 & 3;