It's not very clear what exactly you're trying to accomplish or what specific problem you're having. Post a schematic and program so we can try to help you. If I understand correctly, you have sectors of half a meter and you want only these LEDs to light up when there is a person in a given sector. If so, you can use smart LEDs like WS2812, but keep in mind that you will need a microcontroller with a lot of memory - 3 bytes per LED ie. about 5.7kB just for the LED data. It might be better to divide the LEDs (non smart) also into sectors of half a meter each and control them with a relay or FET - I personally prefer FET.