How do I calibrate the distance sensor? Mine is reading 81cm, but the door is down, there is no car below, and I can’t reach the sensor from standing below it. I’m 6 foot, and can reach to 8 feet, so it’s got at least 250cm of air below it and it’s reading a third of that.
I hope that the paper on the case wasn’t mandatory for it’s function. I removed the cardboard paper from the acrylic puzzle piece case because i thought it looks nicer if I can see inside.
You have to use a large flat surface, like a relatively large cardboard box. Paper is too small because ultrasonic waves are not lasers, they can’t pin point the distance to a small object. It has to be a relatively large flat surface.