https://devzone.nordicsemi.com/f/nordic-q-a/6299/unable-to-mantain-connection-using-gatttoolHi, i am trying to connect via bluetooth using the gatttool on a Raspberry Pi. On the Nordic device I am using the BLE Proximity Demo. Everythings work fine, but after 30 seconds the connection is always terminated by the S110 bluetooth stack(BLE_GATTS_EVT_TIMEOUTen-USTelligent Community 13Wed, 08 Apr 2015 05:43:41 GMThttps://devzone.nordicsemi.com/thread/21983?ContentTypeID=1Wed, 08 Apr 2015 05:43:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6694a7a1-14fc-428e-8596-7510e59e455cAsbj&#248;rn<p>Is the HCI log always the same? Do you always get the disconnect after 30 seconds and always right after the connection parameters has been updated? Do you have a Bluetooth Low Energy sniffer or for example a nRF51-dongle of some kind? You can use the nRFSniffer to have a look at the packages going back and forth in the link as well. That could give you a better view of where it&#39;s failing. It looks to me from the HCI log above that after the connection parameters are updated, the central and peripheral no longer exchange packages.</p> <p>nRFSniffer: <a href="https://www.nordicsemi.com/eng/nordic/download_resource/26386/14/22575263">www.nordicsemi.com/.../22575263</a></p><div style="clear:both;"></div>