Can a node request a status from other node?

  • Hello,

    I'd like to have a "6 button node" that will control lights (in other nodes). Since some lights are far away (not visible), I'm thinking in putting there a led just to signal if the light is currently on or off.

    For this to happen, I guess I'll have to request the status of each light every time a button is pressed (or pool it every 10m or so).

    Is this possible? How?


  • Mod

    @joaoabs yes it is possible. There are multiple threads in the forum. The documentation for how to request information is available at and just above that section is information on how to make a node respond to the request.

  • While it would be possible via request() as @mfalkvidd suggests, I wouldn't recommend to do that in this case. I think it's rather pointless to regularly request variables which only change rarely. It adds a lot of traffic to the network - at least 4 messages (including echos) per request - while the requested values stay unchanged 98% of the time or so. Not to mention that the status LEDs could show a wrong condition for up to 10 minutes if you toggle a light switch right after its state has been requested.

    I'd suggest to use one of the following alternatives instead:

    1. You could have the light nodes send messages to both the gateway and the node with the status LEDs. The status LEDs would update immediately when a light is toggled and there's a lot less unnecessary traffic on the network.

    2. Let the controller handle the logic. Whenever a light node sends a state change to the gateway, tell the controller to send a message to the node with the status LEDs. This method has the same benefits as the one before and it's easier maintainable since you don't need to re-upload sketches to multiple nodes if something changes - just reconfigure a script in your controller.

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