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The software for the A111 radar sensor contains support for Smart Home implementations, which means that you can build a device that detects presence of persons in your home and triggers actions based on this. Perhaps you want to turn on the light automatically when you enter a room? Or get a notification when someone walks up on your driveway? At Acconeer we use it in our office to detect and display if a meeting room is occupied or empty. Follow the steps below to make your own implementation.


To implement this proof of concept, we used the following hardware:

  • XM122 + XA122 + regular coin-cell battery. Find out more and how to buy them on the product page.
  • Raspberry Pi version 3 or later with BLE support



The software for this application is included in the XM122 SDK, and it is easy to get it up and running with a few simple steps.



  • Install Home Assistant on the Raspberry Pi as described here
  • In Home Assistant install the Passive BLE monitor integration as described here

Now the XM122 should be discovered as a motion sensor by Home Assistant.



Depending on the distance you want to detect people or moving objects you will need to change the settings in the ble_monitor_presence. What the settings should be depends a lot on the specific environment and use case, it is recommended to try this out using exploration tool. Once you know your settings you should update the c code for the app.


Keep in mind that the battery life will vary depending on your measurement frequency, since more frequent measurements of course consume more power. In our example we use a 0,2m – 3,2m default range and measure two times per second.




To build your own version of the smart home presence setup, make sure you have all the hardware you need according to above. Combined with a PC running our Exploration Tool you can play around with this and many other use cases. To get started, head over to our Developer site where you find software downloads, getting started guides and more.


If you try this, or work on something else, we’d love to hear about your project! Please get in touch with us on