Using a Meross Wi-Fi switch with OpenHab

The aim of this article to set up and configure a Meross Wi-Fi switch (I’m using an MSS310) with OpenHab2 to work in offline mode — with MQTT and no dependency on the Meross online services.

I gathered most, almost all, of the information required from this thread on github Offline-ONLY support.

For this article, you need to be comfortable with the command line, and have git and node.js installed; you should already have an OpenHab2 setup.

Configure a MQTT server

Install mosquitto

The Meross switch requires a secure MQTT server.

ssldir="/usr/share/licenses/mosquitto/"

# ca
openssl genrsa -out $ssldir/ca.key 2048
openssl req -new -x509 -days 1826 -key $ssldir/ca.key -out $ssldir/ca.crt -subj "/CN=MQTT CA"

# broker
openssl genrsa -out $ssldir/broker.key 2048
openssl req -new -out $ssldir/broker.csr -key $ssldir/broker.key -subj "/CN=broker"
openssl x509 -req -in $ssldir/broker.csr -CA $ssldir/ca.crt -CAkey $ssldir/ca.key -CAcreateserial -out $ssldir/broker.crt -days 360

Edit mosquitto configuration

In /etc/mosquitto/mosquitto.conf:

listener 1883
allow_anonymous true
listener 8883
port 1883
allow_anonymous true
require_certificate false
# replace with your CA Root 
cafile /usr/share/licenses/mosquitto/ca.crt
# replace with your server certificate and key paths 
certfile /usr/share/licenses/mosquitto/broker.crt
keyfile /usr/share/licenses/mosquitto/broker.key

Create cert_regen.sh bash script, which will create a new certificate once a week:

#!/usr/bin/env bash
ssldir="/usr/share/licenses/mosquitto/"

# ca
openssl genrsa -out $ssldir/ca.key 2048
openssl req -new -x509 -days 1826 -key $ssldir/ca.key -out $ssldir/ca.crt -subj "/CN=MQTT CA"

# broker
openssl genrsa -out $ssldir/broker.key 2048
openssl req -new -out $ssldir/broker.csr -key $ssldir/broker.key -subj "/CN=broker"
openssl x509 -req -in $ssldir/broker.csr -CA $ssldir/ca.crt -CAkey $ssldir/ca.key -CAcreateserial -out $ssldir/broker.crt -days 360

Create a cronjob for it

00 22 * * 7 /..../cert_regen.sh

Configure the Meross switch for your Wi-Fi and MQTT server

Get the meross tools, from your command line

git clone https://github.com/bytespider/Meross
cd Meross/bin/src
npm i

Plugin the Meross smartplug.

If it’s not your first time using the switch, press and hold the power button for 5 seconds. Connect to its Wi-Fi access point (Meross_XXX)

Configure the switch for your Wi-Fi and MQTT Server

from Meross/bin/src directory

./meross setup --gateway 10.10.10.1 --wifi-ssid <your-ssid> --wifi-pass <your-pass> --mqtt <mqtt-host-ip>:8883

At this stage, you may hear some clicks from the switch. You can also verify that it has connected using the mosquito logs:

1595295630: New client connected from 192.168.30.7

You should also see some messages from the new switch:

/appliance/1712281825467829030134298f151c4a/publish

{“header”:{“messageId”:”7c2834f83f9cc5b1c7ae1049280a9f3f”,”namespace”:”Appliance.Control.ToggleX”,”method”:”PUSH”,”payloadVersion”:1,”from”:”/appliance/1712281825467829030134298f151c4a/publish”,”timestamp”:1557534775,”timestampMs”:955,”sign”:”f07e2a7ab622997508d359cb89c74038″},”payload”:{“togglex”:{“channel”:1,”onoff”:1,”lmTime”:1557534775}}}

Note the appliance ID in bold above.

On my Mac, I also used MQTT Explorer to view the messages and to determine the appliance id.

Add the switch to Openhab

Add a new thing.

• Using the Paper UI as a new thing.
  • Inbox / “+” on the top of the screen.
  • Select MQTT Binding.
  • Manually Add Thing
  • Select Generic MQTT Thing
  • Give your thing a name, and select your MQTT bridge (configured from step 1).
• Add a Channel
  • On/Off Switch
  • The settings are as follows:
    • MQTT State Topic: /appliance/<appliance_id>/publish
    • MQTT Command Topic: /appliance/<appliance_id>/subscribe
    • Custom On/Open Value: 1
    • Custom Off/Closed Value: 0
    • Incoming Value Transformations: JSONPATH:$.payload.togglex..onoff
    • Outgoing Value Transformation: JS:meross.js

Finally, download the following file, meross.js and save it to your transform directory, for me this is /etc/openhab2/transform/.

The meross.js file creates the JSON structure required to control the switch.