Two-wheel vehicle

Hi,
I’m noob in GB and I want to simulate two-wheel vehicle propelled by stepper motor.

It means that once I would press move button (e.g. uparrow), no matter how long do you hold the button, the vehicle would move forward exactly by 1 step (e.g 1 Blender unit) and stop again.
Other acceptable choice would be to make wheel rotate by 1 step (e.g. 1˚) and whole vehicle would move forward by appropriate distance and stop again.
I constructed something, it moves, but not by steps. Do anybody of you know how do do it via Python?

here is link to .blend file: http://blender3d.cz/forum/download.php?id=5274

Thanks
ps.:sorry my english

looks good not shore what ur asking for though

if u want to to tell it to run for so long u could add a propity witch counts up and the scriped can spot working when u reach this number then use some dynamic text to show its new position??

Do a search on this forum for Tile Based Movement, its a post by Blendenzo. He has done it done with logic bricks and Python.

I found Blendenzo’s post. I could certainly use some ideas, but how to apply to my example? its working copletely different way-I have rotating wheels not only one cube and I need vehicle to steer (using wheels rotatin in opposite direction)