As mentioned in the title, yeah, it works.So what are the first Results:Each time the pants were removed, the system informed us.Two times, it did not work, but I saw it on the camera, so nothing happened. First, I thought, that there is a problem with the transmission, so I installed a second receiver near the room, but this was not the problem. 

It's a mechanical problem. When he removes the pants, with the left hand at the back, the tension to activate the switch is too weak. It's not really a problem, because 10 times out of twelve it worked.

I've already started to build the portable receiver. It won't win a beauty contest, but it works.

Working now on the enclosure and a clean wiring. Will update the receiver part in the "BUILD INSTRUCTIONS" after that.