• State Not Answered
  • Replies 40 replies
  • Subscribers 74 subscribers
  • Views 6193 views
  • Users 0 members are here
Attachments (0)
Nordic Case Info
  • Case ID: 312418
Options

measurement of RSSI or transit time of a message via BLE with the Nordic 52840 and another slave board.

Leonardo Balocchi

I have this problem, with a Nordic nRF52840 board I have to transmit a byte of known length, which I have to select a priori, and transmit it to a second slave evaluation board and then measure the RSSI value and the time it takes for the data packet to arrive depending on where the board is located, thus also going back to the distance value at which the two boards are located.
I would then also like to do the same thing with my android smartphone used as a slave.

I have tried to follow the examples I can find of nRF connect for desktop a bit, and in particular the codes available in visual studio code, but the standard codes there do not seem to answer my question.
Could you perhaps help me by explaining where to find an example code to modify to achieve this, and how to program the second board via the nRF52840?

thanks in advance!

Parents Reply Children
  • 0 in reply to Amanda Hsieh

    Thank you Amanda for your reply.

    I have managed to get the two Nordic boards talking.
    Now what I would like to be able to do is to save the various RSSI, IFFT and RTT values in a file, so that I can then graph the time trend of these values.
    Can you please suggest a method for doing this?

    If there is a possibility, it would also be useful to save this file inside the nRF52840, so that I don't have to have it connected to the PC during measurements. And then later transfer those data saved in the non-volatile memory to the PC.

    Thank you again for your support!

  • 0 in reply to Leonardo Balocchi

    Hi, 

    Leonardo Balocchi said:
    I have managed to get the two Nordic boards talking.

    That's good news. 

    I would suggest at least one DK connect PC to check the log and make sure these two DK work as expected. Then, you could also save those values by the terminal tools. 

    -Amanda H.

  • 0 in reply to Amanda Hsieh

    Hello Amanda, thanks for your reply.

    The two boards communicate, but I have encountered a problem.
    I'll explain the hw and sw setup: one board is the nRF52840 which was loaded with the nrf_dm application, the other is the evaluation board BC840E which has the default program with which it was pre-loaded (so I didn't program it).

    I placed the two boards 1m apart, and for the 2.4 GHz frequency I should have a path loss of 40.04 dB.
    On the BC840E board I connected a 5 dBi gain antenna.
    Knowing that the nRF52840 in transmission I set it for 0 dBm and that the antenna gain on the nRF52840 is 0 dBi, I should see about -35 dBm of RSSI, the problem is that the measured RSSI is about -2 dBm.
    (if I don't put the external antenna on the BC840E the count doesn't add up, in fact I see rssi_openspace=199.53, which isn't correct anyway).

    I can't tell if I have misinterpreted the RSSI value, can you please clarify this for me?

    Thanks in advance!

  • 0 in reply to Leonardo Balocchi

    Hi, 

    I would suggest programming both boards with the nrf_dm application and comparing the result of using two nRF52840DKs with the nrf_dm application.

    -Amanda H.

  • 0 in reply to Amanda Hsieh

    How can I copy the programme on the nRF52840 to the BC840E board as well?
    I have the 10-wire connector to connect the two boards, but then what do I have to do from VS Code?

    Can I directly connect the BC840-E to the computer and flash it from VS Code as I did with the nRF52840?

Related
Terms of service