MySensors MQTT gateway and serial rs485 sensor node communication

[ehome]

Hi all,

I would like to setup an sensor network with an ethernet gatway and wired connected sensor nodes. (RS485)

Gateway: Arduino Uno R3 with W5100 ethernet shield.
Sensor Nodes: Nodes are connected with gateway via wired rs485 connection (cable).

Connection Flow 1 # Get sensor values:
Arduino Sensor Node (RS485) --> Gateway --> MQTT --> OpenHab2

Connection Flow 2 # Issue commands to sensor node: (e.g. activate relay)
OpenHab2 --> MQTT --> Gateway --> Arduino Sensor Node (RS485)

Is that possible with the MySensors library?
Because the RS485 gateway example I found on this page doesnt seem to use MQTT communication to OpenHab?

Regards,
Simon

[mfalkvidd]

@ehome welcome to the MySensors community!

It should be as easy as changing

#define MY_GATEWAY_SERIAL

to

#define MY_GATEWAY_MQTT_CLIENT

and add the configuration parameters listed on the mqtt gateway page.

[ehome]

Thanks for your fast reply.

That sounds easy.
And you think that the communication between sensor nodes and Gateway are still possible via wired RS485?

I tried to find an example on this site for sending Information from Gateway to sensor nodes. (via SendMessage ?)
For example I like to Switch on/off an light that is connected to an relay board at my sensor node.

Communcation Flow:
OpenHab2 --> MQTT --> Gateway --> RS485 --> Sensor Node --> Relay Board

Currently I have an working RS485 Connection between my Arduino Uno's with the use from SoftwareSerial library.
During my testings I realized, that the message that I triy to send "Hello" will be sent to the other arduino char by char. Is that true?

Because I tried to raise up an pin on HIGH with "if(msg == "Hello")..." But it doesn't worked.

Will the sendMsg method from the MySensor library handle this out of the box?

Regards,
Simon