I feel this is the most appropriate exchange for this question I hope someone could bring some insight into an area I know very little about.

I would like to find a way to detect and log the time which an object enters and leaves a specific area.

The area would need to be defined in a 3 dimensional way and the object would be made specifically for the purpose of being detected.

Thanks for any help.

  • 1
    $\begingroup$ your question is unclear (no clearly defined parameters and no actual information about anything) .... you may get an answer to something like this I have a sensor X, which I use to detect object Y. How do I restrict the sensor X, so that the object Y is detected only on the left side of line W? $\endgroup$
    – jsotola
    Jun 24, 2018 at 22:38

1 Answer 1


one of the ways to do this is by using the military way i.e. by using 3D Radars. But, it is quite difficult and expensive to build one.

But one of the cheaper and more interesting way is by using Beacons. Beacons are small devices used mostly for indoor mapping and tracking. You can place minimum 3-4 beacons in your room which will transmit BLE and WiFi signals.

The object you say which will enter the room will have a WiFi and BLE scanner or a sensor, which will connect to these signals. Depending upon the RSSI i.e. the Received Signal Strength from each of the beacons you can identify the location of your object.

This method is called Triangulation Method. enter image description here

ESP32 is one of the best device you can use for this. You can find some details here

You can also use accelerometer and gyroscope sensors to map the positioning. You can find some reference here:



  • $\begingroup$ You have way to little information to know that this could be a solution. Beacons e.g. won't give you accurate borders of the area and are static. $\endgroup$
    – FooTheBar
    Jun 25, 2018 at 7:32
  • $\begingroup$ You need to map your beacons according to your room first. It is possible as I am already working on this project. $\endgroup$
    – ron123456
    Jun 25, 2018 at 7:47
  • $\begingroup$ Yes of course this is a possibility to track something indoors. But so far, he could want to track a drone hovering above a forest. How would you apply your solution in this case? $\endgroup$
    – FooTheBar
    Jun 25, 2018 at 8:32
  • $\begingroup$ Well, I wrote my answer with reference to indoors. And obviously beacons are only useful for indoor navigation. For geo-location tracking you have a lot of solutions. $\endgroup$
    – ron123456
    Jun 25, 2018 at 8:43
  • $\begingroup$ Thanks for the info, apologies if my question was a bit vague. $\endgroup$
    – Dave
    Jun 25, 2018 at 21:33

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