Setup nRF Cloud with own boards by using AT commands

RE: Setup nRF Cloud with own boards by using AT commands

Jun Qing ZOU — Wed, 01 Sep 2021 08:09:27 GMT

"I see for example a "#XMQTTEVT: 1,-128" response and can't work with SLM's MQTT anymore"

MQTT event type: MQTT_EVT_DISCONNECT, result: -128 (ENOTCONN)

MQTT client lose connection to the broker.

"I have tested this also with a public MQTT broker without TLS. Once I disconnect the MQTT client, I cannot restart another MQTT session"

Please wait to test MQTT in NCSv1.7.0 in which re-connect to MQTT broker is now possible.

Or you can try SLM in NCS master now.

RE: Setup nRF Cloud with own boards by using AT commands

Kevin Kotinkar — Wed, 25 Aug 2021 16:36:16 GMT

Hello Bernd, hello Øyvind,

I wanted to share some of my latest results:

1.) I am able to connect to the nRF cloud using SLM and AT Commands, at least I succeed initially. The MQTT client ID seems to be important as well, and has to match with what you configure on nRF cloud:

My AT command is:
(client-ID is: nrf-<IMEI of the nRF9160>)
AT#XMQTTCON=1,"nrf-352656106651436","","","a2n7tk1kp18wix-ats.iot.us-east-1.amazonaws.com",8883,16842753

Response is:
#XMQTTEVT: 0,0

I noticed that I have to publish/subscribe to the right topics in order to continue manually, will need to further investigate here.

2.) However, if something is wrong on the input, I see for example a "#XMQTTEVT: 1,-128" response and can't work with SLM's MQTT anymore. I cannot disconnect using AT#XMQTTCON=0 or connect again. I have tested this also with a public MQTT broker without TLS. Once I disconnect the MQTT client, I cannot restart another MQTT session.
I have to reset the nRF9160 DK in order to use the MQTT AT commands again, otherwise I always get an "ERROR".

(I am using the SLM of NCS SDK 1.6.0)

[quote userid="107293" url="~/f/nordic-q-a/78806/setup-nrf-cloud-with-own-boards-by-using-at-commands/326560#326560"]Are the MQTT AT commands not active?[/quote]

@Bernd - the SLM application basically wraps AT commands around the MQTT libraries, so these AT commands are specific to the application, not to the modem. Thus, wenn running the AWS FOTA application, I believe you do not have them available by default .

[quote userid="107293" url="~/f/nordic-q-a/78806/setup-nrf-cloud-with-own-boards-by-using-at-commands/326560#326560"]Do I need a TLS socket before I can connect?[/quote]

No, I didn't need to set this up. Within SLM this is done in the background of the MQTT AT command.

Best regards,
Kevin

RE: Setup nRF Cloud with own boards by using AT commands

Bernd — Wed, 25 Aug 2021 12:58:18 GMT

Hello Øyvind,

seems that the certificates are deleted / damaged if I do an over-programming with the debugger (but they are still listed with "AT%CMNG=1"?)

I programmed first the AWS FOTA sample and then overwrite the certificates - now it connects correctly.

client_id: nRF9160_BMS

[mqtt_evt_handler:120] MQTT client connected!

[mqtt_evt_handler:177] SUBACK packet id: 2112

[mqtt_evt_handler:177] SUBACK packet id: 2114

[mqtt_evt_handler:167] PUBACK packet id: 34934

[mqtt_evt_handler:182] default: 9

I used the AWS FOTA sample & AWS because I have more possibilities to setup the cloud.

So in general the AWS and the MQTT connection works.

Unfortunately the AWS FOTA software does not accept any MQTT AT commands and quit with error -8

AT#XMQTTSUB="xyz",1

E: Error while processing AT command: -8

Can't this not be used together?

Are the MQTT AT commands not active? Any switch to select or do I have to add this manually?

If I go back to Serial LTE modem software, programming the certificates and using this MQTT commands it still says just error

Do I need a TLS socket before I can connect?

Something like "AT#XSSOCKET=1,1,1,1000,0" ?

Assuming that the command

"AT#XMQTTCON=1,"nRF9160_BMS","","","a2lfsfrs57xcmu-ats.iot.eu-central-1.amazonaws.com",8883,1000"

is doing the same as the "err = mqtt_connect(&client);" there must be a difference which I do not see at the moment...

Could you or your developers setup a connection to any AWS thing just using the ATs?

Regards,

Bernd

RE: Setup nRF Cloud with own boards by using AT commands

Øyvind — Wed, 25 Aug 2021 10:47:16 GMT

Hello Bernd and Kevin,

[quote user="Kevin Kotinkar"]MQTT connect error -111 means connection refused.
This could be related to wrong/missing provisioning / registration of your nRF9160 on AWS.[/quote]

Yes, this is correct.

I'm currently trying to find some more answers from our developers as well.

[quote user="Bernd"]MQTT FOTA Sample Settings[/quote]

Do you mean AWS FOTA sample? Are you trying to connect nRF Cloud or AWS?

Thanks.
-Øyvind

RE: Setup nRF Cloud with own boards by using AT commands

Kevin Kotinkar — Wed, 25 Aug 2021 10:22:20 GMT

Hello Bernd,

I'll let Øyvind confirm but what I remember, MQTT connect error -111 means connection refused.
This could be related to wrong/missing provisioning / registration of your nRF9160 on AWS.

I am digging into this as well now.

Best regards,
Kevin

RE: Setup nRF Cloud with own boards by using AT commands

Bernd — Wed, 25 Aug 2021 09:32:07 GMT

Hi Øyvind,

Because it seems that there is a more basic problem with connecting I have setup an AWS thing and try to connect it with MQTT AT commands and the FOTA example. I cannot get a connection in general.

MQTT FOTA Sample Settings
■ Security tag for TLS credentials <CERT_SEC_TAG> 1000
Custom MQTT client ID <USE_CUSTOM_CLIENT_ID>
■ Client ID <CLIENT_ID> nRF9160_BMS
■ AWS IoT MQTT broker hostname <MQTT_BROKER_HOSTNAME> a2lfsfrs57xcmu-ats.iot.eu-central-1.amazonaws.com
■ AWS IoT MQTT broker port <MQTT_BROKER_PORT> 8883
■ MQTT message buffer size <MQTT_MESSAGE_BUFFER_SIZE> 256
■ MQTT payload buffer size <MQTT_PAYLOAD_BUFFER_SIZE> 256

The FOTA returns:

SPM: NS image at 0x20200

SPM: NS MSP at 0x2001e248

SPM: NS reset vector at 0x25c91

SPM: prepare to jump to Non-Secure image.

*** Booting Zephyr OS build v2.6.0-rc1-ncs1  ***

MQTT AWS Jobs FOTA Sample, version: v1.0.0

Initializing modem library

Initialized modem library

LTE Link Connecting ...

LTE Link Connected!

IPv4 Address 35.156.166.89

client_id: nRF9160_BMS

ERROR: mqtt_connect -111

What could be the problem?

Regards,

Bernd

RE: Setup nRF Cloud with own boards by using AT commands

Øyvind — Wed, 25 Aug 2021 08:59:52 GMT

Hi Kevin,

I'm afraid we do not have a setup/sample on how to connect nRF Cloud using Serial LTE Modem at the moment. The command you provided looks correct to me, although I'm not able to test similar here.

The Asset Tracker and the nRF Cloud library should provide information to what is needed to connect. I'm afraid I do not have any more information at the moment.

Kind regards,
Øyvind

RE: Setup nRF Cloud with own boards by using AT commands

Kevin Kotinkar — Tue, 24 Aug 2021 13:51:35 GMT

Hello Øyvind,

Before implementing the scenario in SW, the customer wants to manually connect to the nRF cloud using AT commands. Please share a setup / connection to nRF cloud using SLM & AT commands (MQTT).
I'll be able to test this tomorrow.

Assuming certificates are set correctly under sec tag 16842753, is below command enough?:

AT#XMQTTCON=1,"MyNordic_DK_nrF9160","","","a2n7tk1kp18wix-ats.iot.us-east-1.amazonaws.com",8883,16842753

Or do we also need to set appropriate kfconfig switches for AWS as described here:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.6.1/nrf/include/net/aws_iot.html#lib-aws-iot

Thanks,
Kevin

RE: Setup nRF Cloud with own boards by using AT commands

Øyvind — Mon, 23 Aug 2021 08:09:05 GMT

Hi Bernd, I can recommend reading through our documentation regarding the nRF Connect SDK, especially "Working with nRF91 series".

RE: Setup nRF Cloud with own boards by using AT commands

Bernd — Fri, 20 Aug 2021 13:36:52 GMT

Hi Øyvind

Thanks for link.

A firmware update to 1.3 allows me to use the KEYGEN command as a first step.

I have to go through the other steps now (its not obvious if you are no expert)

Regards,

Bernd

RE: Setup nRF Cloud with own boards by using AT commands

Øyvind — Fri, 20 Aug 2021 10:52:46 GMT

Hello Bernd,

Have you looked at the nRF Cloud documentation? From the Serial LTE Modem you should be able to communicate with nRF Cloud using either MQTT or REST API.

Kind regards,
Øyvind