https://devzone.nordicsemi.com/f/nordic-q-a/35879/connect-interval-updateI am now using nrf52832 sdk14.2 development, as a slave device, I want to set the slave&#39;s Bluetooth interval is 1S, I set the following parameters: #define MIN_CONN_INTERVAL MSEC_TO_UNITS(40, UNIT_1_25_MS) #define MAX_CONN_INTERVAL MSEC_TO_UNITS(250,en-USTelligent Community 13Thu, 28 Jun 2018 09:15:39 GMThttps://devzone.nordicsemi.com/thread/138050?ContentTypeID=1Thu, 28 Jun 2018 09:15:39 GMT137ad170-7792-4731-bb38-c0d22fbe4515:72ba7346-62eb-4124-940a-911bed64820dhaakonsh<p>Hey Jim,&nbsp;<br /><br />The Central device will set the connection interval that best suites its needs given a requested range from a peripheral device. This means that you are not guaranteed to get a connection interval that you desire. Smartphones usually operates as BLE Central devices and therefore they set the connection parameters. The BLE host and controller on the smartphones also have to compete with BT classic and WIFI for radio time and therefore your desired connection parameters can be hard achieve.&nbsp;<br /><br />Cheers,</p> <p>Håkon.</p><div style="clear:both;"></div>