U-blox Sara N211 (NB-Iot) to Cayenne



I’m trying to use the NB-IoT chip from u-blox with the Cayenne Library. Is there someone who did something like that? The chip supports UDP messaging, but not TCP. Is this possible?

Thanks in advance,



Sorry, I don’t think it will work. I believe all the connection methods use TCP, is that right @rsiegel @bestes?


Oke, thanks for you answer. MQTT-SN is not an option then. Are there somewhere examples how the payload string is build up?


Sure, the docs page is over here https://mydevices.com/cayenne/docs/cayenne-mqtt-api/#cayenne-mqtt-api-manually-publishing-subscribing


Thanks for tagging me @adam . Now my turn to tag someone :blush:

@croczey @eptak First post I’ve seen for NB-IoT. Are you able to help at all?



Hi @MichaelW

Currently the best way to use your NB-IoT enabled device is to pass the data through our MQTT broker.

The link @adam gave you is the correct documentation, however, I think what you are looking for is our payload / topic structure which can be found here: https://mydevices.com/cayenne/docs/cayenne-mqtt-api/#cayenne-mqtt-api-mqtt-messaging-topics

This will show you exactly where to publish the data, and how to format the payload.

Let me know if you need any help!



Hi all,

Thanks for your replies, The documentation is really helpful. I’m working on it, if I need any help, I let you know!

Kind regards,



Hello @croczey ,

I already sent data to ip address: I used the pubsub client (https://github.com/knolleary/pubsubclient) and make a client class for the NB-IoT module. As far I can see now, I do not receive a message back when I sent the connect message.

Can this be because I can only send UDP messages?

Here you can see the payload for connect to socket:

[R]: 0,132
[R]: OK

For som extra informatie page 82 of the datasheet Datasheet Sara N211

Thanks in advance,