Getting Power Consumption Updates from Meross Switch over MQTT

Setup, Configuration and Use Beginners
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1

Hi,

I have a Meross Wi-Fi switch configured to run connected to a local (On-Premise) MQTT Server.

I want to trigger an event based on Power Consumption changes.

Unfortunately, the Meross switch doesn’t post power consumption changes to the queue unless you send an MQTT command first. That is, you send a message to the queue requesting power consumption, and the device sends a response to the queue with the current power consumption.

I’m guessing that the best way to do this is to create a rule that runs at a specific interval (once per minute would do for me) that sends the MQTT command.

This seems a little clunky, so I wondered if there was a better way?

Thanks.

2

No, if the device can’t be configured to send periodically, that’s the best way I can think of.

3

Thank you; but that doesn’t appear to be an option.

Is there a better way to create a recurring MQTT command without using a rule?

4

Why do you think that? :wink:

  1. create your MQTT Thing
  2. add the MQTT Channel for the command
  3. link this Channel to a item
  4. create a cronjob rule, which updates the item
  5. item-update sends the command to the switch
  6. switch sends is power consumption

you could write a shellscript/pythonscript/NodeRed/… doing the #4. part for you - but somewhere you have to trigger the power consumption message, if the device can’t do that alone.

(if you don’t like an item for it, you could also just trigger the channel from the rule, but that’s cosmetics)

5

Optimism!

Thank you for your help.

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6

Just to be clear, some bindings do let you set up a polling period in the Thing. The HTTP binding comes to mind.

However, the nature of MQTT is that it’s supposed to be a push. When a device has something to say, it should publish it. Let the subscribers decide what’s worth processing or not. I truth, your Meross Switch is miss using MQTT by forcing you to “query” for this information.

So while the concept of a binding that can poll is not unheard of, it would be a misuse of MQTT and therefore the MQTT binding doesn’t directly support it.

But that’s OK, that’s one of the things that rules are for, to handle those use cases that are outside the norm. And it’s really no more difficult to set up a rule to do this than it is to set up the HTTP binding to do this.

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7

Hi, I also have some Meross Wi-Fi switches (MSS310) that should provide power consumption.
Currently I am only able to switch them on or off.
What is the command you send to get power consumption via MQTT?

8

Hi,

I’m not at home to confirm it, but I had this example in my notes (it could be completely wrong, sorry).

The power consumption response is published to the topic set in the from field in the example below: /app/openhab-1/subscribe.

{
  "header": {
    "messageId": "messsage1666263095432",
    "namespace": "Appliance.Control.ConsumptionX",
    "method": "GET",
    "payloadVersion": 1,
    "from": "/app/openhab-1/subscribe",
    "timestamp": 1666263095,
    "sign": "0AFC53D660183EED4187EA7BAE8C7B63"
  },
  "payload": {}
}
9

I was wrong, sorry.

The namespace should be [Appliance.Control.Electricity] (checkout meross/protocol.md at master · arandall/meross · GitHub)

Something like (not tested).

{
  "header": {
    "messageId": "messsage1666264361474",
    "namespace": "Appliance.Control.Electricity",
    "method": "GET",
    "payloadVersion": 1,
    "from": "/app/openhab-1/subscribe",
    "timestamp": 1666264361,
    "sign": "400D3A15960079AFCC2E27C0BAA16DA9"
  },
  "payload": {
    "electricity": {
      "channel": 0
    }
  }
}
1 Like