5V 28BYJ-48 4-Phase Stepper Motor with ULN2003 - help with it

Hi all.
Excuse my english please.
I have this kind of stepper
5V 28BYJ-48 4-Phase Stepper Motor with ULN2003
from ebay off course
http://www.ebay.co.uk/itm/5V-Stepper-Motor-28BYJ-48-With-Drive-Test-Module-Board-ULN2003-5-Line-4-Phase-DX-/221359243670?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item338a0a0196

I have a sketch and it works well for 360 degree and return ok to the begining.
I have a issue or a problem with it , maybe i don’t know well how i use it.
If i cut the power of arduino or power of stepper and if it remaining in a different position like normal one , how can i put it in right begining position , or it must came back at power on?

I hope i explain well.
Thanks a lot to all.

New Bitmap Image (3).bmp (2.66 MB)

The usual way to do this is to have a switch (perhaps a microswitch) at the "zero" position. Then, at startup, the motor is turned step by step until a lever moved by the motor presses the switch which tells the Arduino that the motor is at the zero position.

...R

Many thanks.
I hoped to escape by this solution but i saw it is the only way.
Please tell me if for servo motors is the same thing?
Thanks a lot again.

Assuming you mean radio control servos, they will do what you want because the signal from the Arduino just tells them what angle to move to. However they won't be as precise as a stepper motor.

The usual servos just move through 180 degrees (some a bit less, some a bit more). If you need position control up to about 3 full revolutions you can use a sail winch servo.

You can also get "continuous rotation" servos (or modify standard servos to make them rotate continuously) but they don't have position control.

If they are suitable, servos will be much easier to install and program than stepper motors.

...R

thanks a lot