https://devzone.nordicsemi.com/f/nordic-q-a/41939/connect-inteval-time-is-fixedi use the BLE uart example in SDK11.0 to test. I delete the UART hardware init and just use the BLE send data to phone every 500ms. I found whatever i set the MIN_CONN_INTERVAL and MAX_CONN_INTERVAL, the connet interval seems fixed is 50ms. I addeden-USTelligent Community 13Wed, 02 Jan 2019 14:23:42 GMThttps://devzone.nordicsemi.com/thread/163478?ContentTypeID=1Wed, 02 Jan 2019 14:23:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cae250fc-385d-42af-8d6a-8d543e0df3d3Einar Thorsrud<p>Hi,</p> <p>The connection interval is set by the central when it connects. The peripheral can request a different connection interval (min and max). How do you do that? The SDK include a <a href="https://www.nordicsemi.com/DocLib/Content/SDK_Doc/nRF5_SDK/v15-2-0/lib_ble_conn_params">Connection Parameters module</a> to help with this, and you can for instance refer to the <a href="https://www.nordicsemi.com/DocLib/Content/SDK_Doc/nRF5_SDK/v15-2-0/ble_sdk_app_hrs">HRS example</a> to see how it is used.</p><div style="clear:both;"></div>