S110 Disconnects when in connection with S120

[Phil Beeson]

I have a peripheral based on S110 that is connected to by a central running S120.

The connection is established, the S120 interrogates the service and enables notification on the correct characteristic. At this time, the peripheral isn't actually generating any notifications. Connection events occur every 100ms and empty data PDUs are exchanged.

After about a minute, the peripheral terminates the connection with an LL_TERMINATE_IND link layer control message.

If I examine the disconnect notification event from the SD I see that the disconnection reason is 0x16 (Local host Disconnected).

I don't see this termination behaviour when the peripheral is connected to the nrf master control panel on Android, so presumably I need to do somthing on the S120 to ensure this doesn't happen, but I need to understand why the disconnect is occuring first.

Any ideas what's causing the S110 to disconnect, I can't see anything in the code examples that suggest there's a timeout on the connection?

disconnect_1.pcapng.txt

[Pål Håland]

Hi,

at packet 674 I see that the peripheral send some data on L2CAP (Looks like garbled data) and 30 seconds after that a timer triggers, causing the disconnection.

Do the peripheral do a Connection Parameter Update Request? In that case the central should handle the event BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST, and issue a sd_ble_gap_conn_param_update. (To respond to the request)

BR Pål