Hello,
If there is also a possibility, when connected to the Gui-O MQTT server, to be able to receive, whenever requested, the Timestamp, without the need to have a Gui-O APP open?

If so, how to do that?

Regards
Fernando

Hello Fernando.

The MQTT protocol by itself does not include a timestamp, so you would need to create the timestamp on the client side.
You could also have a reference device (could also be a PC) that publishes the timestamp to some topic. You can then subscribe to this topic on your microcontroller.

Best regards,
kl3m3n