Central device disconnects BLE connection after 30 seconds

[grzegorz]

I have problem with BLE connection being constantly disconnected after 30 seconds. It is always disconnected by central device. It doesn't matter if it is iOS, Android or Windows 10 PC. It doesn't matter if my device is paired or not. I think that my code could be somehow not compatible with BLE standard requirements. How can I check the specific reason of disconnection? All I see now is reason 0x13 Remote User Terminated Connection. But it doesn't help much. My code is based on ANCS and HRS FreeRTOS examples.

Here is complete over the air log captured with Wireshark:

disconnect.pcapng

[Einar Thorsrud]

Hi,

The disconnect reason is what is shown as "Error Code" in the sniffer trace - remote user terminated connection (0x13). This does not indicate an error in itself, it just states that the central side decided to disconnect (for some reason). A 30 seconds match for instance a GATT timeout, but I do not see anything in the sniffer trace that it should be the problem. In that case you should get disconnect reason 0x08 (timeout). Could it be that the software running on the central devices decide to disconnect for some reason? Do you use custom apps?

Which SDK and SoftDevice version do you use?

[grzegorz]

Hi,

I use custom apps on Windows and iOS, but they don't make the disconnection. On Android there is just nRF Connect used for tests. So I think this must be something about BLE stack or BLE standard.

I use SDK 15.3 and SoftDevice 6.1.1.