Easy. Take note then set biner as grid representation and some loop. Done.
You can just summon the blocks by drop them right away but this way more fascinating!
The preview showing moving sensor set with slow translation to show how it works. In actual gameplay the sensor moving very quickly that no one notice it’s movement. Except the little blue box that just rotates 90 degree on it’s place.
Done by rotating the sensor/detector. Sufficient technique.