I am working on a project to create a pipe of 75 cm long with a addressable LED-strip underneath it. I want it to react to your hand when you hold it above the pipe. I am trying to light up the LED’s that are underneath your hand when you move your hand above the pipe (distance between 1 and 10 cm).
I have tried an ultrasonic distance sensor, but that is not very reliable. Next to that my goal is to embed the sensor in the pipe.
Currently I am looking into using/multiplexing around 20 PIR sensors(passive infrared sensors, I use the hc-sr501). Unfortunately it seems to also detect other things than my hand.
I was wondering whether anyone knows a better way to determine the position of my hand so I can use it to address the right LED’s. I have attached a rough sketch to visualize the concept.