MQTT subscription failure

RE: MQTT subscription failure

m.saadat — Mon, 04 Jul 2022 10:12:27 GMT

Thanks. I followed the link and now I'm able to connect.

RE: MQTT subscription failure

Didrik Rokhaug — Fri, 01 Jul 2022 12:02:57 GMT

That API creates JITP certificates for the client. Part of the provisioning process involeves disconnecting and reconnecting the client.

I recommend you follow this guide for how to create credentials for your client: https://docs.nrfcloud.com/Guides/GettingStarted/Devices#generating-credentials-on-a-computer

(note that step 3, 4 and 5 is not necesary for a desktop client. In step 2, you can use the nrf_cloud_provision.py script if you don'w want to call the REST API manually)

With credentials created that way, I have been successfully subscribed to prod/<team ID>/m/d/<client id>/c2d and <client id>/shadow/get/accepted. I was also able to receive the shadow on the latter topic by publishing to $aws/things/<client id>/shadow/get

Finally, you should note that client IDs starting with "nrf-" is reserved for evices created by Nordic Semiconductor (e.g. DKs and Thingys). nRF Cloud therefore treats them slightly differently. You should choose client IDs that do not start with "nrf-"

RE: MQTT subscription failure

m.saadat — Thu, 30 Jun 2022 07:46:05 GMT

That is the case. I use the same clientId and credentials that are received by calling the 'POST on api.nrfcloud.com/.../certificates'. If I use a different clientId (added '-2' at the end), it does not connect (connection breaks before the connection is complete):

Client nrf-**************-2 sending CONNECT
Error: The connection was lost.

When the Thingy91 is disconnected, the same thing happens, and the connection breaks (even when using the same clientId as Thingy91).

Where can I get the new clientId for new connections? Do I need a different certificate to be able to connect to the MQTT broker?

RE: MQTT subscription failure

Didrik Rokhaug — Wed, 29 Jun 2022 11:54:05 GMT

[quote user="m.saadat"]I can connect, but as soon as Thingy91 publishes something to it, the connection breaks.[/quote]

Are the Thingy and the mosquitto client using the same ID and credentials?

If that is the case, being disconnected is expected. Client IDs must be unique, i.e. cannot be used by two different clients at the same time.

RE: MQTT subscription failure

m.saadat — Wed, 29 Jun 2022 11:26:45 GMT

Hi. I should have added that. I tried all the topics. I just added that one as a sample. The same result is happening even when I tried, for example, this one:

m/d/${deviceId}/c2d

Or any other topic in that table (I even tested the ones that are only for publishing). And for the topic

${device_id}/shadow/get/accepted

I can connect, but as soon as Thingy91 publishes something to it, the connection breaks.

RE: MQTT subscription failure

Didrik Rokhaug — Wed, 29 Jun 2022 11:16:49 GMT

Hi,

Could you try to subscribe to the specific topics you want to subscribe to, instead of using wildcards?

You might not be allowed to subscribe to all subtopics of prod/${tenantId}/m, which is probably why you get kicked out.

Best regards,

Didrik