@Michael_K ,
If we go from the front to the back this is what is needed:
1 Node: For example a door bell.
This node sends information to a gateway.
2 The gateway takes the message from the node and sends this to a controller. For instance Openhab or Domotics. This can be done in several ways. MqTT being one.
3 Controller: takes the information and displays it to you.
So in my case, I hardcode Node ID and CHILD ID (the complete door bell is a NODE whereas CHILD IDs may be the button pressed and maybe temperature reading at the same time).
This sends to Gate way that takes the information and creates a MqTT message.
What this message is, please read the instructions on this site.
@ericvdb
Yes, I know about the 5V. But the adapter brings it down to 3.3V for the radio, that is the reason for using it and the adapter is equipped with the AMS 1117 3.3V chip. Seems to work OK but I really do not have any hard facts to prove it.
One thing I may test is to wire the 5V also directly to this adapter instead of taking it out from the Arduino 5V pin. This is to find out if this Arduino Nano clone might have too small capacity for feeding the radio at certain occasions.