How do I find out if devices already bonded after building up a connection?https://devzone.nordicsemi.com/f/nordic-q-a/19597/how-do-i-find-out-if-devices-already-bonded-after-building-up-a-connectionHello, I have an BLE application were I want, for security reasons, to allow a connection only if a button is pushed or if the devices already have bonded before. The Button is no problem I just wait for the BLE_GAP_EVT_CONNECTED event. Then I asken-USTelligent Community 13Fri, 10 Feb 2017 11:29:11 GMTRE: How do I find out if devices already bonded after building up a connection?https://devzone.nordicsemi.com/thread/76255?ContentTypeID=1Fri, 10 Feb 2017 11:29:11 GMT137ad170-7792-4731-bb38-c0d22fbe4515:39d85149-e547-4a54-82bb-a0a7597a1da6Petter Myhre<p>If you wait for the BLE_GAP_EVT_CONNECTED event you have already allowed connection, if you want to disallow connections you should advertise with a whitelist containing the addresses of the bonded devices, and advertise without whitelist when the button is pushed.</p> <p>If you want to allow connections but only let devices pair when the button is pushed I think you can use pm_sec_params_set().</p> <p>When the button is pushed call pm_sec_params_set() with the security parameters you want to use when pairing/bonding, when button is released call pm_sec_params_set(NULL) to disallow pairing.</p> <p>I guess you could alternatively call pm_sec_params_set() with or without NULL depending on button state every time you get an event from the SoftDevice.</p><div style="clear:both;"></div>