aymannox:
Yes they start in the same time , as i tell you for example M1: 62 steps, M2 : 0 steps, M3: 259 steps, M4: 9 steps
You have not said whether they must all stop at the same time after having moved different numbers of steps - that is the essential thing I want to know as it has an important impact on how you write the code.
Can you provide a diagram of the powder dispenser machine you want to create - it will help us to understand what you are doing?
And you have not posted a link to the datasheet for your stepper motor.
...R