Long Range Vehicle Sensor Using Data Radios

Here is another fun project I just finished up.  My client wanted to be able to know if a vehicle (a train actually) is coming from a mile away.  We used a Banner radar sensor in retroreflective mode, a Banner DMX100 controller/radio, and a DX80 multihop radio.  The system can be expanded with additional repeaters if more range is needed.  I used power tool batteries because they are easy to replace, relatively inexpensive, and high quality.  Here is a short video showing a test I did in my neighborhood of the setup (without proper mounting hardware)