Hi Pavlin,
The motor manufacturer can tell you the optimal speed of the motor. It is usually listed on the datasheet along with the voltage to achieve the speed. The datasheet will also list a maximum starting speed for the motor.
Are you still running the motor at 12V?
Is it possible to provide a scope capture of current of one of the windings? If not, can you provide the voltage across the sense resistor, the xOUT1 and xOUT2, and the STEP input. The current can be determined with this.
The motor manufacturer can tell you the optimal speed of the motor. It is usually listed on the datasheet along with the voltage to achieve the speed. The datasheet will also list a maximum starting speed for the motor.
Are you still running the motor at 12V?
Is it possible to provide a scope capture of current of one of the windings? If not, can you provide the voltage across the sense resistor, the xOUT1 and xOUT2, and the STEP input. The current can be determined with this.