Side Project – Microwave Motion Detector

I wanted to build a driveway monitor that alerts me in my office when a Fedex truck makes a delivery or evil Zombies looking for fresh brains.  Our driveway is reasonably large and I thought that a standard IR motion detector may not be ideal. Those tend to have a pretty short range and also get triggered easily by deer for example.  What I was looking for was a long range, detector that could be tuned to just about the mass of a car (assuming Zombies arrive by car).

Enter the XYC-WB-DC module that I picked up on E-Bay for a couple of bucks, it promises 360 degree, tuneable motion sensing.  This YouTube video explains well how the sensor works but unfortunately, otherwise, there is very little documentation in English.  It seems to have been designed as a motion switch for light fixtures etc in factories where high ceilings are more common. It does sense motion through walls which I thought would be neat but in the end turned out to be a nuisance.

Setting it up was pretty straight forward except that I broke a soldering point on (both) devices.  The soldering points are directly on the board and when the cable that I soldered onto it snapped off accidentally, it took the entire point and connection with it.  Now I can not figure out a way to attach a resistor that tunes the delay after activation.  In principle this isn’t a big deal but the default 30second delay is a nuisance to set up and I decided to shelve the project for now. While I had it running, the real nuisance was the lack of direction and its ability to penetrate the table top or enclosures.  For some applications that is a useful feature and I may get back to it in the future, for now its back in box.