Nordic Thingy 52 (ble6lowpan): unexpected interface down event while sending MQTT messages

[mvataleu]

Hi all,

We've tried to port IoT SDK features (IPv6 over Bluetooth low energy) to Nordic Thingy 52. As base, we use FW for Nordic Thingy 52 from GitHub We need to send MQTT messages from device to local MQTT broker. For now, we connected from BLE router to Thingy via this method. After IPv6 interface up we connect to the local MQTT broker and start sending messages. All works well in first few minutes, and we can see incoming messages via Mosquito.

After that, we receive interface down event and connection crushed.

syslog here

OS: Ubuntu 16.04 LTS, Linux kernel version: 4.10.0-40-generic, bluetooth_6lowpan module version: 0.1, Mosquitto broker (MQTT) version: v3.1, IoT SDK version: 0.9.0, Nordic-Thingy52-FW version: 2.0.0, Soft Device version: s1xx-iot-prototype3_nrf52_softdevice.

We can't understand what the reason because event comes from Soft Device.

We need to understand possible reasons, why we receive interface down event.

Thanks in advance.

Regards Mikhail.

[Petter Myhre]

Firstly, I would strongly recommend you to use IoT SDK v1.0.0. This was integrated into the main SDK at version 14.1. You should now use 14.2. A lot of improvements have been made. This might solve your issue, see this.

Also, you might get some tips from this. The BLE logs might give some clues on what is going on.

Just to confirm, you are getting the BLE_6LO_EVT_INTERFACE_DELETE event? And that is where nrf_driver_interface_down() is called?