Programing help

[aaaaaa_aa]

How do I program my Lego Mindstorms v3 robot to go straight until it detects an object and then return to where it was? What I don't know how to do is to go back to where it was without knowing how far it is going to go because the object it has to detect can change its place. 

Edited November 14, 2023 by aaaaaa_aa

[Lok24]

you can use the motors as a sensor (rotations in degrees)

- get the value when you start

- get the value when object detected

- move back with the difference of the two

 

[aaaaaa_aa]

Thank you, it works very good.