This turret is built only with parts from the NXT set.
Except for the 2 launchers, one is from the Batmobile set 7781 and one from the Jango Fett sett 8011.

The code starts rotating the turret until an object is detected within 60cm, when that happens the number 
of rotations on the motor is stored and the turret continues rotating until the distance to the object 
has changed by more than 10cm.
The turret than rotate in the opposite direction for half the time passed since the initial detection of the 
object.
The result of this is that the turret is now aiming at the middle of the object.
Then the same thing happens vertically and 1 rocket is fired.
The cannon and US-sensor move down again, the turret rotates half the width of the object again to pass it 
and starts looking for a target again.

RBT-file can be downloaded at:
http://www.mysharefile.com/v/3065829/guardturret.rbt.html


If you have more questions, you can contact me at lego@zanthrax.nl

september 17 2006