PNC Robot , help plz ~~~~~~~

I thinkin of the CNC robot , in some way different .

i want to use just an microcontroller to determine the coordinats ,

neglect the computer to do that ...

so , i think of the light sensor but its not accurate ...

if there any idea , i would be thankful .....

thanx ......

shams......

Whilst we enjoy helping people; in order to help you we need to know how far you've progressed. Please post what you've already done, including any ideas you've had. If you need help that your lecturer should have provided, please tell us (and your lecturer) what you found was lacking. It is not right if you manage to attain a high grade from the help we have provided if your lecturer is negligent; it will make them appear to be better than they really are and put you at an unfair advantage to your classmates.

It also would help us to know more about your education, geographical location and experience with the English language.

plz stop using "plz"!!!!!!!!!