small package proximity sensor


I am planning on building led strip lighting incorporated into my skirting boards that turns on as you walk by them. My idea is to use an arduino to sense through proximity sensors at foot height when someone is walking by and turn on the LEDs within 1 meter or so and turn them off as you pass by.

Is there a small proximity sensor or something similar that could be used. The other option is to use room PIRs but then i would need to switch on a whole area of LEDs as the room PIR would not be as precise.

I am open to suggestions.



Ultrasonic sensors are dirt cheap. Since they return a distance, you get to decide exactly how close someone needs to be to trigger your response.

PIR sensors sound the most practical.

They only sense what they "see", so you can mask them (inside the lens so it does not interfere with the appearance) to a narrow field.