Bluetooth Presence Sensor

  1. 10 months ago

    Mark S

    17 Feb 2019 Pre-Release Testers, Xojo Pro, XDC Speakers

    Does anybody have experience on a Raspberry Pi with Bluetooth?

    I am exploring solutions to detect the presence of a bluetooth device (a smartphone) and then send a text message (SMS) to remind them to clock in to their shift. I think I could do this on a Windows or Mac with some MBS functions (which I have licensed) but it does not work in Linux or Raspberry Pi. A Pi is preferred due to pricing and physical size.

    I would even consider "SHELLing" out to a some sort of command line tool and then process the result. A bit of Internet searching indicates some Bluetooth tools do exist for the Pi environment.

    The data needed would be some unique identifier that I can associate with an entry in a database then create the text message.

  2. Jean-Yves P

    17 Feb 2019 Pre-Release Testers, Xojo Pro Europe (France, Besançon)

    https://www.youtube.com/watch?v=KNoFdKgvskU
    https://www.youtube.com/watch?v=fmhjtzmLrg8

  3. Russ L

    18 Feb 2019 Pre-Release Testers, Xojo Pro

    if using a Rpi3 then

    sudo hcitool lescan

    should return the list of devices that respond.

  4. 9 months ago

    Mark S

    23 Feb 2019 Pre-Release Testers, Xojo Pro, XDC Speakers

    Russ,

    I finally got to test the hcitool on my Rpi3 and it does work. Now I just need to figure out which ID corresponds to which device.

    My iPhone has a Bluetooth ID listed in General>About but that ID does NOT appear in the hcitool lescan list. I can turn off BT on the phone and back on and watch the ID re-appear on the Rpi3 with the lescan but it does not match.

    Is the Low Energy ID different?

    Thanks for the tip.

    Mark

  5. You might find that the iPhone is not be using the actually BT MAC address when starting the BTLE advertisement. Might be part of a privacy framework in place.. just a hunch. You can create (as far as I recall) an app for your phone that will advertise a specific service with unique characteristics that you should show up using hcitool. It'll be a case of using gatttool to interrogate the devices and look for the services.
    It's very near-field though meaning that you only have a short window to detect the BTLE signal and interrogate the device.

    I use a technique like this for a BTLE device that I have fitted to my motorbike but that's obviously not a smartphone and the bike doesn't move around like guys at work.
    I don't think Android devices have the same MAC address kung-foo in place as iOS devices.

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