send mysensor data to other node

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Hi all,

I’m trying to build a kind of Display node in a MySensors network connected through a serial gateway to Pimatic.
What I would like to achieve is to send the latest available sensor data of different nodes to this Display node.

In the MySensors forum I discussed this and did only find a solution if the sensor nodes would send dedicated messages directly to this display node.
This would mean I would have to update all nodes involved to also send their data to this Display node (besides the gateway).
I think this is very inconvenient since existing working nodes have to be reprogrammed to get the info to the Display node.
Also using a retrieve function in the Display node directly from the sensor node is not the solution for me since these sensor nodes need to be alive all the time which is not feasible for battery nodes.

Since latest values of sensor nodes are available in Pimatic I would like to retrieve them from this Pimatic database to the Display node by active request done by the Display node to the Pimatic environment.

Is there a way to do this?
To be more specific: I have a solar weather station node in my garden and would like to display some of the data in a seperate node inside my house.

At this moment you can send 5 different values to a node from pimatc. The plugin does not support more (yet I hope).
This is how you do it:
in a rule you set send custom "V_VAR1" nodeid: "11" sensorid: "6" cmdcode: "180" (cmdcode is the value you want to transmit).

You can use V_VAR1 to V_VAR5. In your displaynode you read the values into variables and you can display them.

@DavidZH thanks for helping me.

MySensor nodes expect in their receive function a message like “node; child sensor; command; ack; type; payload” where
node = node ID of destination node (my Display node)
child sensor = child sensor ID of sensor to update (not the case in my node but I could use the sensor node of one of my wheaterstation nodes since I use this value to detemine what sensor data to fetch).
command = 1 to indicate a ‘set’ function;
ack = 0 to indicate no acknowledge is requested from the receiver;
type = value to indicate sensor data type, i.e. temperature = 0;
payload = the actual value of measured sensor of the specific type, i.e. 18.4 in case of temperature type.

Does this ‘send custom’ command you suggest send the data this way or do I need to fetch/handle this in a different way in my Display node?
Where are V_VAR1 to V_VAR5 for when the actual value is already in the ‘cmdcode’?

@DavidZH

Got it working with this:

I use this rule:

If $weerstation.Temperatuur gets updated then send custom "V_VAR1" nodeid: "100" sensorid: "1" cmdcode: "$weerstation.Temperatuur"

In the Display node (100) I have following receive function to fetch the message:

void receive(const MyMessage &message)
{
  // Explore message
    switch (message.sensor)
    {
      case 0:  // Humidity sensor
      {
        lcd.setCursor(13, 1);  
        lcd.print(message.getFloat());
        break;
      }
      case 1:  // Temperature sensor
      {   
        lcd.setCursor(13, 0);  
        lcd.print(message.getFloat());
        break;
      }
      case 2:  // Light sensor
      {
        lcd.setCursor(10, 3);  
        lcd.print(message.getUInt());
        break;
      }
      case 3:  // Barometer sensor
      {   
        lcd.setCursor(10, 2);  
        lcd.print(message.getFloat());
        break;
      }
      case 4:  // Barometer Temperature sensor
      {
        break;
      }
      case 5:  // Rain sensor
      {
        break;
      }
    }
}

this is working fine for case 1: temperature.

Where do I need the V_VAR1 for?

This method I would call a push mechanisme: controller is sending to node.
Is there also a pull mechanisme possible where I would like the node to request a value from the controller?

Yeah, I know what you mean. This is the way the pimatic-plugin is built. Unfortunately as far as I know this will not work without the V_VARx designation. But to be really sure you’d have to ask the plugin developer, @sweebee.

@DavidZH @sweebee the rule option is now working also for the other 3 sensors.

I’m using the V_VAR1 in all 4 rules and it is in for me as a dummy, not holding any value.
When the Pimatic variable is updated by the MySensor sensor node, the rule is extecuted to send a MySensor message and the value in the Display node is updated.

Still I would like to have the option where a node can retrieve a Pimatic variable actively.

A work around could be to let the Display node have a dummy sensor which is to be used as a trigger in Pimatic to execute a rule with the ‘send custom’ command.
In that way the Display node can be in control.
The drawback is you still have to define dedicated rules for all nodes using the feature of retrieving Pimatic variables values.

So an option to retrieve variable data from Pimatic by a node is very desirable