nRF52832 BLE UUID value incorrect

I don't know if this is a hardware or a software problem. My nRF52832 code runs correctly on a PCA10040 development board (UUID = E9:4A:AF:04:D2:16). My custom hardware advertises correctly but the UUID is incorrect (C9:7C:A5:8B:19:EB). The 32MHz xtal is +/-10ppm @ 12pF load. I have tried everything that I can think of including a PCB layout using a 50 ohm SMA antenna, same problem.

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  • Thank you for your comments.

    An alternative PCB layout (attached) UUID is EB:9E:40:D1:D2:F1 is closer but still not correct.
    The Johanson 2450AT42A100E chip antenna does not require a matching network.
    The 32MHz crystal is YXC X322532MOB4SI I will try a 20pF load. Unfortunately I am not able to measure the exact frequency.
    The L3 and C18 components are 0402 in this layout. I cannot find your reference layout, please send me the URL.
    By changing the UUID in my Android app I am able to communicate perfectly with the nRF52832.
  • Unfortunately changing the load cap to 22pF made no difference, the UUID remains the same as before.

  • Let me try a different approach, where is the MAC address / UUID stored in the nRF5_sdk_17_1/examples//ble_perpiheral/ ble_app_hrs project?

  • Hi,

     

    Metaresearch said:
    Let me try a different approach, where is the MAC address / UUID stored in the nRF5_sdk_17_1/examples//ble_perpiheral/ ble_app_hrs project?

    As mentioned:

    Håkon Alseth said:
    It is to be expected that the MAC address differs from one device to another. By default, the mac address used is loaded from the FICR DEVICEADDR register, which is uniquely generated for each device.

    More detailed info here:

     RE: How to get 6 byte mac address at nrf51822 

    This is written for 51-series devices, but is valid for all nRF5-series devices.

     

    If there's another 6 byte string/address/ID that you're changing, please share a screenshot/log or something to let me know what you're actually trying to change.

     

    Metaresearch said:
    Unfortunately changing the load cap to 22pF made no difference, the UUID remains the same as before.

    The MAC address will only change if the firmware changes it.

    Is the "CL" value 12 pF for your xtal? You must do a calculation based on the formula that I previously posted to ensure that the 32M is loaded properly.

    Metaresearch said:
    The Johanson 2450AT42A100E chip antenna does not require a matching network.

    I highly recommend that you add a pi-network (shunt-series-shunt) and use a 0 ohm for the series-component as a place-holder.

    You currently have no way to tune your antenna design, and antennas will always need tuning towards your specific design.

    If you check other antennas from Johanson, you will see that they recommend antenna tuner components.

    Metaresearch said:
    The L3 and C18 components are 0402 in this layout. I cannot find your reference layout, please send me the URL.
    By changing the UUID in my Android app I am able to communicate perfectly with the nRF52832.

    Capacitors shall be NP0. Inductors should have a resonance freq > 3 GHz (for instance murata LQP-series).

    Please also take note of the orientation and grounding of the capacitor on the ANT pin:

    This is crucial, as also noted in the PS:

     

    Kind regards,

    Håkon

Reply
  • Hi,

     

    Metaresearch said:
    Let me try a different approach, where is the MAC address / UUID stored in the nRF5_sdk_17_1/examples//ble_perpiheral/ ble_app_hrs project?

    As mentioned:

    Håkon Alseth said:
    It is to be expected that the MAC address differs from one device to another. By default, the mac address used is loaded from the FICR DEVICEADDR register, which is uniquely generated for each device.

    More detailed info here:

     RE: How to get 6 byte mac address at nrf51822 

    This is written for 51-series devices, but is valid for all nRF5-series devices.

     

    If there's another 6 byte string/address/ID that you're changing, please share a screenshot/log or something to let me know what you're actually trying to change.

     

    Metaresearch said:
    Unfortunately changing the load cap to 22pF made no difference, the UUID remains the same as before.

    The MAC address will only change if the firmware changes it.

    Is the "CL" value 12 pF for your xtal? You must do a calculation based on the formula that I previously posted to ensure that the 32M is loaded properly.

    Metaresearch said:
    The Johanson 2450AT42A100E chip antenna does not require a matching network.

    I highly recommend that you add a pi-network (shunt-series-shunt) and use a 0 ohm for the series-component as a place-holder.

    You currently have no way to tune your antenna design, and antennas will always need tuning towards your specific design.

    If you check other antennas from Johanson, you will see that they recommend antenna tuner components.

    Metaresearch said:
    The L3 and C18 components are 0402 in this layout. I cannot find your reference layout, please send me the URL.
    By changing the UUID in my Android app I am able to communicate perfectly with the nRF52832.

    Capacitors shall be NP0. Inductors should have a resonance freq > 3 GHz (for instance murata LQP-series).

    Please also take note of the orientation and grounding of the capacitor on the ANT pin:

    This is crucial, as also noted in the PS:

     

    Kind regards,

    Håkon

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