https://devzone.nordicsemi.com/f/nordic-q-a/17943/what-can-cause-ble-reponse-slowSorry about a so broad question. But this is what I have experienced but don&#39;t know where to look. I have done a few project using BLE with RTX. Just typical stuff similar to the heart rate example. All good. For my current project, after finisheden-USTelligent Community 13Thu, 24 Nov 2016 15:10:58 GMThttps://devzone.nordicsemi.com/thread/69207?ContentTypeID=1Thu, 24 Nov 2016 15:10:58 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8f69af6d-9ac5-4638-be1a-a2f8a9b497b1Paul<p>Talking about connection intervals, I checked nRF Connect log. The delay I am experiencing is very close to be either 4 seconds or 2 seconds. I will check your link and look into it. Thanks Paul</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/69206?ContentTypeID=1Thu, 24 Nov 2016 10:10:49 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8b9f4153-44d8-4b73-94d7-54adba110446Petter Myhre<p>The first thing I would check is the connection interval. It is the central device that dictates the connection interval, the peripheral can only request to update the connection parameters. How to check the actual connection interval is described <a href="https://devzone.nordicsemi.com/question/56471/check-ble-connection-interval/">here</a>.</p><div style="clear:both;"></div>