Mysensors MQTT Gateway Help to conf

I have Mysensors MQTT Gateway running on ArduinoUNO + Ethernet Sheild, i use this example

And i have 3 questions

  1. On this link write “MQTTGateway will act as a broker, a server.” if i understand this, i don’t need to instal other MQTT Brocker. Аm i right ???

  2. Is this possible to work only with 2 parameters setted
    All you need to do here is to add

  3. need information how to make my ithems file, i dont understand the “topic”

Number node1_temp "Temp [%.1f °C]" (node1,all) {mqtt="<[mysensor:MyMQTT/20/10/V_TEMP:state:default]"}

What means:
MyMQTT ???
20 ???
10 ???

I hope I can answer all of your questions:

  1. Yes, you are right. You will not need another MQTT broker.
  2. Yes, the only mandatory parameter is the url parameter, so every other value will have a default value. You can read about the default values here.
  3. In general the topic is defined by the publisher (your sensor) and it’s just a unique name under which your data is stored. If you want to subscribe to this data you need to subscribe to the same topic. Most often you will find a hierarchical notation, because it is the most convenient and structured way to publish and subscribe data. Since you are using MySensors the format of your topics is defined by the MQTT Gateway itself: MyMQTT/[nodeId]/[childId]/[variable_type].

10X for you help

my sensor send this to gateway

find parent
send: 255-255-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,st=bc:
find parent
send: 255-255-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,st=bc:
T: 29.00
find parent
send: 255-255-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,st=bc:
H: 31.00

my gateway recive this

0;0;3;0;9;send: 0-0-255-255 s=255,c=3,t=8,pt=1,l=1,sg=0,st=bc:0
0;0;3;0;9;read: 255-255-0 s=255,c=3,t=3,pt=0,l=0,sg=0:

do you know what is my node id and chilg id ???

No, sorry. I have never worked with MySensors.
Maybe someone else?

If you subscribe to the mqtt broker using another service you can see what is being broadcast and see the node and child ids.

EG. I use a chrome extension called MQTTLens.
I also use an android app called MyMQTT.

In either of these you can subscribe to your broker ip and port and then see all mqtt traffic. Just subscribe to all topics by subscribing to #. You can then identify the MySensors topics and use that to configure your openhab items.

Hope this helps.

10X for helping me, i sove this problem with bild in serial monitor on arduino program