Question

Hi, I am trying to connect the RUT955 to google's MQTT (or HTTP) bridge to communicate with Cloud IoT core. I am planning to use this to forward sensor data to google cloud. In order to authenticate the device one has to generate a json web token signed by the device private key, and send the json web token in the MQTT password field (for HTTP, in the request header). The json web token expires within 24h, therefore I need a way to periodically update the password. Is there any way to do this?

Answer 1

Hello,

Which kind of data will you get from RUT955 and send to Google cloud?

If will you send modbus data via mqtt or http you can use this service and also edit the header.

• https://wiki.teltonika-networks.com/view/RUT955_Modbus#Modbus_Data_to_Server

The json web token expires within 24h, therefore I need a way to periodically update the password. Is there any way to do this?

• You can create your own script and call it daily  via crontabs.
• User scripts --> https://wiki.teltonika-networks.com/view/RUT955_User_Scripts
• Crontabs --> https://wiki.teltonika-networks.com/view/Crontabs

Nevertheless, if you want to use another IoT platfomr instead google cloud, Teltonika already have some packages ready to use with some platforms.

• https://wiki.teltonika-networks.com/view/RUT955_Package_Manager

Any further doubts, please let me know.

Regards.

Comments

Thanks, I am now able to generate json web tokens on the RUT955. How can I configure the "Modbus Data to Server" parameters using the shell script (to add the password)? I.e. where is the file I need to write to?

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Hi.

By default, modbus data to server won't use the custom script.

Maybe you can create a listening port in your localhost, so your modbus data to server can send the data to the router itself (in the port you configured) and manage all in your custom script.

Another way, the modbus database is stored in the /tmp folder. If you want to create a customized data sender, you can do it into your custom script.

I think there are some other ways using the bash interface.

Any further doubt please let me know.

Regards.

Answer 2

Hi Thoander,

I'm facing the same issue, generating JWT outside of RUT, with a python script over Ubuntu and then using it inside my RUT955 Application, it works for 24h.

I have a micropython version of the script but some imports are missing after installing micropython at RUT955. Could you provide some details about how you are generating/refreshing the JWT inside RUT955?

Regards,

Comments

Hi, I ended up making a bash script to generate and sign the JWTs with openssl-commands.