Distance measurement

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  • Hello I am working on a variation of this project (https://www.youtube.com/watch?v=azT2rosE­o0k

    ) for my internship .

    There is one change in the code that is troubling me .

    I want to be able to print the relative distance of the puck from the firebeetle or the firebeetle from the puck into the arduino serial monitor .

    Any ideas ,guides or recommendations on how to do that would be appreciated .

    Thanks

  • Sun 2019.06.09

    Hello @user100855,

    This is untested, but couldn't a table of distances be constructed from signal strength, and through interpolation send that output to the Firebeetle?

    http://www.espruino.com/Reference#l_NRF_­setTxPower
    http://www.espruino.com/Reference#t_l_NR­F_setAdvertising

  • I would say it's not trivial.
    Depending on you environment, all kinds of things can affect the signal strength, not just range and TX power: orientation, objects, walls, people in the room.
    Probably you should start recording range and RSSI values, and if it's consistent, do some interpolation (maybe even just use excel, and pick one distance value for every 10 dBm difference)

  • Hi! As other have said, all you have to work on is RSSI, and that can change quite a lot - devices have different emissions patterns so depending on orientation (or even if your hand is in the way) you'll get a different RSSI.

    By adding some filtering for RSSI (an average or median?) you could improve that a bit, but to get better it's really help to have multiple receivers in different places.

  • Thank you all I am going to try and create it through the RSSI values .
    Do you recommend any material for reading or watching ?

    @Gordon @AkosLukacs @Robin

  • If you have an android phone, get nRF Connect by Nordic Semi, and watch the RSSI graph as you walk around. I think it's worth to get an idea what to expect. Was using nRF connect just yesterday to test the range of BLE things.
    Of course you can do this with NRF.findDevices or NRF.setScan, just nRF Connect gives you a graph in a couple of seconds.

  • Mon 2019.06.10

    re: 'Do you recommend any material . . .'
    re: 'Hello I am working on a variation of this project (link) for my internship'

    Isn't the purpose of the Internship to demonstrate the knowledge gained and education acquired by applying that learning experience in obtaining the goal, in reaching the solution to the problem you are in the process of solving yourself? If not, I'd request a refund from that institution as they have let you down!   ;-)

    Oh, . . . I see, . . . You are 'researching' what the experts may know. . . .



    While using search may be time-consuming, here is an article I found useful on the maths behind calculating the distance given the db loss value.

    https://www.electronicdesign.com/communi­cations/understanding-wireless-range-cal­culations

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Distance measurement

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