Automatically disconnection iOS

RE: Automatically disconnection iOS

JensMander — Mon, 27 Jul 2026 14:58:55 GMT

I ran into the same problem; connection is terminated after 95sec. by peripheral (BL652, running NUS) with LL_TERMINATION_IND and error code 0x3b (unacceptable connection parameters). Connection paramters came from the central, a Garmin Edge 1050 GPS device, enforcing these values by LL_CONNECTION_UPDATE_IND to interval 90ms, latency 0, supervision timeout 4000msec.

What can i do to fix this) It is not possible to change BLE parameters of central (Garmin Device), i can only adapt the BLE stack of the peripheral, build with Nordic SDK.

RE: Automatically disconnection iOS

Michel — Thu, 11 Feb 2016 16:25:29 GMT

I changed the filename.

It looks like my problem is solved indeed. The connection is still okay even after more then 2 hours.

Thanks for pounting me in the right direction.

RE: Automatically disconnection iOS

run_ar — Thu, 11 Feb 2016 16:19:22 GMT

Looks like the attachment function doesn't like spaces in the name. However, I guess it doesn't matter as you seem to have solved your problem :)

RE: Automatically disconnection iOS

run_ar — Thu, 11 Feb 2016 15:43:09 GMT

Glad to hear you solved the problem. iOS has strict rules for what connection parameter requests it will accept. You can see these in Apples Bluetooth design guidelines. Note that you can choose whether or not to disconnect in your application.

RE: Automatically disconnection iOS

Michel — Thu, 11 Feb 2016 14:14:12 GMT

I found the MIN_CONN_INTERVAL and MAX_CON_INTERVAL values in my Nordic code where changed to small values. 10ms for the MIN and 15ms for MAX. After changing this value to 20 ms and 75 ms the connection with the iOS device remain stable after the 95 seconds.

I don't know why I changed it, but I did!

Problem solved for me at this moment.

RE: Automatically disconnection iOS

Michel — Thu, 11 Feb 2016 13:36:03 GMT

I made a sniffer trace and found that there is a "LL_TERMINATE_IND" about 95 seconds after the "CONNECT_REQ". The error code after the "LL_TERMINATE_IND" is 0x3B "Unacceptable connection parameter"

After 35 seconds a L2CAP Rcvd Connection parameter update request from slave to master was rejected by the master.

RE: Automatically disconnection iOS

run_ar — Thu, 11 Feb 2016 12:34:53 GMT

Can you upload a sniffer trace that shows what is happening on air?