Many beacons now come with sensors such as light sensors, temperature sensors or accelerometors to, for example, know if a beacon is moving or not to turn it off or on. Estimote also has a magnetometer sensor to act as a magnetic metal detector. While it can only detect metals that have a magnetic field, it can detect them from a greater distance.
This can be used to detect cars for smart parking lots or measuring traffic. It can also be used to “fingerprint” a location so it cannot be spoofed. Beyond just triggering messages in a shotgun approach, beacons can add a lot more intelligence to a space. Additional sensors on beacons such as magnetometers are worth thinking about to add more location-relevant data to your application.
Check out this article to learn how to use magnetometer’s and Estimote’s beacon.