https://devzone.nordicsemi.com/f/nordic-q-a/81124/questions-about-pairing-of-phones-and-peripheralsHi The chip used is nrf52832, the SDK version is a peripheral device v13, and the central device uses v16. The referenced example is ble_app_multirole_lesc and has been changed to security mode 1 level 4. The two devices of nrf52832 were wellen-USTelligent Community 13Thu, 28 Oct 2021 06:18:53 GMThttps://devzone.nordicsemi.com/thread/336321?ContentTypeID=1Thu, 28 Oct 2021 06:18:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:56eb3f3e-3e64-452e-844a-c3916ae9feabMr.Chu<p>It was solved by bonding on an Android phone.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/336153?ContentTypeID=1Wed, 27 Oct 2021 10:04:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:17ea902b-afda-4f21-991d-897ec1399a74Mr.Chu<p>Do I need to give a SEC Start signal from the Android phone?</p><div style="clear:both;"></div>