https://devzone.nordicsemi.com/f/nordic-q-a/16677/nrf51-refuses-connection-parameter-negotiationHi, I have an nRF51 project using SD110 and SDK8.0 that refuses connection parameter negotiation. I a handler that would disconnect bluetooth when a connection parameter negotiation fails and it would disconnect every time it connects to somethingen-USTelligent Community 13Tue, 27 Sep 2016 09:01:12 GMThttps://devzone.nordicsemi.com/thread/63816?ContentTypeID=1Tue, 27 Sep 2016 09:01:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7ff67609-9757-45c8-8b51-7211ee2e91d1bjorn-spockeli<p>Did you also call <code>conn_params_init()</code> before calling <code>services_init()</code>? If that is the case then I think the note below from the SDK v8.0.0 documentation of <a href="http://developer.nordicsemi.com/nRF5_SDK/nRF51_SDK_v8.x.x/doc/8.0.0/s110/html/a01013.html#gacd9789a0a4c90cfea2ba2656f6408080">ble_conn_params_init()</a> explains the behaviour</p> <blockquote> <p>If the negotiation procedure should be triggered when notification/indication of any characteristic is enabled by the peer, then this function must be called after having initialized the services.</p> </blockquote> <p>-Bjørn</p><div style="clear:both;"></div>