• The reference shows:

    NRF.setSecurity({passkey:"123456", mitm:1, display:1});
    

    This works - but it looks like you changed it to display:0. I think the BLE stack gives INVALID_PARAM because it figures you can't have a passkey if it's not displayed anywhere so the user can read it.

    I could be wrong here but my understanding was even if you scribbled "123456" on the side of the device or wrote it in a manual, that's enough to quality for display:1.

  • Tkank you, I will try this later!
    It's unintuitive but somehow makes sense. It should then be reflected somewhere in the manual that some combinations are invalid.

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