https://devzone.nordicsemi.com/f/nordic-q-a/76406/unexpected-123456-pin-code-valueHello, In our product, we use the S132 v3 softdevice and legacy pairing with a static pin code. At startup, this pin code (that can be changed by the user) is read from flash and then passed onto the softdevice using sd_ble_opt_set(BLE_GAP_OPT_PASSKEYen-USTelligent Community 13Thu, 17 Jun 2021 12:03:37 GMThttps://devzone.nordicsemi.com/thread/315860?ContentTypeID=1Thu, 17 Jun 2021 12:03:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9383d866-e3fc-4e74-b5b7-5fa1413d7812Sigurd<p>Hi,</p> <p>From the <a href="https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v3.0.0/structble__gap__opt__passkey__t.html#a9e16c43a1b5706db1120bd0742a48c50">documentation</a>, it will either be the&nbsp;<span>6-digit ASCII string you set it to with&nbsp;sd_ble_opt_set(), or &quot;If this is NULL, the SoftDevice will generate a random passkey if required.&quot;. So assuming this is not a one-time thing(it was 123456 just 1 random time),&nbsp; I think you somehow must have set it to&nbsp;123456 with&nbsp;sd_ble_opt_set()</span></p><div style="clear:both;"></div>