Thread MQTT-SN Example publish and subscribe can not combine operations

RE: Thread MQTT-SN Example publish and subscribe can not combine operations

Jørgen Holmefjord — Tue, 20 Jul 2021 13:09:45 GMT

Please post your second issue in a new ticket, as it does not seem related to the topic of this thread. Then we will help you out and look into it.

RE: Thread MQTT-SN Example publish and subscribe can not combine operations

Jørgen Holmefjord — Mon, 12 Jul 2021 15:40:51 GMT

I think that is only required to change it if you modify the Mesh-Local Prefix for the network. If you use the default in the precommissioned examples (fdde:ad00:beef), it should work without modifications.

RE: Thread MQTT-SN Example publish and subscribe can not combine operations

Jørgen Holmefjord — Thu, 01 Oct 2020 09:20:55 GMT

Hi,

[quote user="Rick"]but it still will display "message could not be processed" error.[/quote]

Yes, since the GW search uses a broadcast address, this message will be received by all nodes. You can suppress the message by handling the event in message_handle in mqttsn_packet_receiver.c:

case MQTTSN_SEARCHGW:
    NRF_LOG_INFO("Another Thread device searched for MQTT-SN GW, ignore and return success");
    err_code = NRF_SUCCESS;
    break;

This message type is sent by the client, and should only need to be handled by the gateway.

Best regards,
Jørgen

RE: Thread MQTT-SN Example publish and subscribe can not combine operations

Rick — Sat, 26 Sep 2020 02:02:33 GMT

Hi Jørgen,

Thank you for your help!

I can work of MQTT from your example.

but it still will display "message could not be processed" error.

Best Regards,

Rick.

RE: Thread MQTT-SN Example publish and subscribe can not combine operations

Rick — Wed, 23 Sep 2020 15:09:01 GMT

Hi Jørgen,
Thank you for your reply.

1. Can this combined example support two devices at the same time?
If using only one device, it can work, but using two devices, it will display "message could not be processed" error.
this is my step.
a) device A subscribe to the topic of device B publish
b) device B subscribe to the topic of device A publish
c) device A Press button 2 to search for GW.
d) device B Press button 2 to search for GW.
e) device A will display "message could not be processed" error
Pls kindly help advise how to solve it?

2. you say "I tested this on my end, and I am seeing the same behavior. I believe that the unhandled event message happens because the second board is in a state where it does not expect to receive this event when the first board does a Gateway search. The examples are most likely not written with multiple publishers in mind." from "Thread Border Router networking fail", now I just search for GW, it display "message could not be processed" error.
Pls kindly help advise how to solve it?

Best Regards,

Rick.

RE: Thread MQTT-SN Example publish and subscribe can not combine operations

Jørgen Holmefjord — Wed, 23 Sep 2020 14:52:59 GMT

Hi again,

Here is a combined example that supports both publishing and subscribing to topics (modified in mqttsn_client_subscriber).

Press button 2 to search for GW.
Press button 3 to connect to the GW.
Press button 4 to subscribe to the topic.
Press button 1 to publish to the topic.

devzone.nordicsemi.com/.../main.c

Best regards,
Jørgen

RE: Thread MQTT-SN Example publish and subscribe can not combine operations

Jørgen Holmefjord — Wed, 23 Sep 2020 14:40:20 GMT

Hi,

I tested with one subscriber and one publisher client, and followed the steps in the example. This works well and I'm able to subscribe to topics on one of the devices and publish from another device. I'm still seeing the "message could not be processed" error, but this does not affect the functionality.

The example is only written for a single publisher and subscriber.

I will look into if it is possible to merge the publisher and subscriber examples to run on a single board.

Best regards,
Jørgen