I’m considering using an OpenPIR facing upward to sense whether there is motion near a shoebox-sized object placed on the floor. By “near” I mean within a 6’ radius, but it doesn’t have to be precise. But if I have multiple objects, each with their own PIR sensor, and they are placed such that their detection areas overlap, will they interfere with each other?
No, they are passive devices and won’t interfere with one another. 