@dpcons MQTT sounds intimidating and looks imitimidating when you see all of the options available.
Here's the scenario:
You want to send a message. That's the -m option followed by a space and the message between " "
the location, topic, is a tree, -t option, separated by forward slash / eg. MyRootTopic/MyTopicsSub/MyTopicSubSub
It's as easy as that if your broker, the MQTT service (program) is on the same computer as the sending program. Usually it's not.
Specifiy the location, the host, of the broker with the -h option followed by the host name or IP address
The retain option, -r is important but explaining it is beyone the scope of this message
Receiving, subscribing, to a topic is just the same, but you wouldn't have the -m message
If you subscribe from the command line, the subscribe function waits indefinitely for messages published to the subscribed topic (unless you use the -C option) ^C to terminate the command.
A tamotized device with the MQTT configured will create a number of topics on the broker. Home Assistant will see this automatically, if you have the Tasmota and MQTT Integrations installed.
The MySensors MQTT gateway takes care of MQTT communication for a MySensors device. Again the MySensors and MQTT integrations.
I use both.
-OSD
Thanks for the answer. I meant that Mysensors has ESP32 support but only in terms of WIFI. It supports e.g. stm32 with ENC or W5500 modules - and the question is whether and how to add ESP32 support with LAN8720 module. I am not considering using ESPHOME or MQTT - I want to have native communication with the controller that implements my control schemes on its side. I try to program KC868-A16 but it does not matter - the question is whether such support can be added in a simple way.