Unable to get nRF52840 Thread MQTT-SN example working - MQTTSN_SEARCH_GATEWAY_NO_GATEWAY_FOUND

[Mahesh Venkitachalam]

I have a Thread network setup using nRF52840 as per the documentation below, using the Raspberry Pi image provided by Nordic.

http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.thread_zigbee.v1.0.0/thread_border_router.html?cp=4_2_0_1_0_8

I am able to ping external IPv4 addresses from a thread node using CLI.

I am trying to get the mqttsn_client_publisher example working, but I get the MQTTSN_SEARCH_GATEWAY_NO_GATEWAY_FOUND error in the program.

I have confirmed that paho-mqttns-gateway.service is running on the pi, and that /etc/paho-mqttsn-gateway default values are correct.

Any idea why gateway discovery is failing? The thread network seems alive and it's able to ping to the internet via the pi gateway,

I am using nRF5_SDK_for_Thread_and_Zigbee_v1.0.0.

I'd appreciate any help with the above error.

Regards

Mahesh

[Mahesh Venkitachalam]

I found the problem. The Nordic MQTT-SN code uses a different UDP6 port compared to the one in the conf file.

Need to make the following change to /etc/paho-mqtt-sn-gateway.conf:

#GatewayUDP6Broadcast = ff33:40:fdde:ad00:beef:0:0:1

GatewayUDP6Broadcast = ff03::1