This plugin provides the ability to publish out any user defined variable to an MQTT Broker. It is based on the code found here This is my first plugin so odds are there will be some bugs although so far seems to be working fine.

This plugin is designed for use on systems running UI7.

User defined Variables to watch
User defined Device Alias which makes Logic much more intuitive and makes it easier when replacing devices

Code:

{"Payload":{"DeviceId":45,"OldOnOff":"1","OnOff":"0","Time":1453209965},"Topic":"Vera/Events/TestSocket"}

Upload the attached files
Create a new device with device_file set to D_SensorMqtt1.xml
Set desired variable watches on the Watchdog tab
(optional) Set desired Alias on the Alias tab
Have fun

There are a few dependencies that should be copied to /usr/lib/lua folder

You can subscribe to a topic by creating a child device :

1. Add a new device and choose a type (e.g. "D_BinaryLight1.xml" or "D_TemperatureSensor1.xml").
2. Reload LUUP engine.
3. Change the attribut "id_parent" with the id of the MQTT plugin device.
4. Reload LUUP engine and refresh your browser.
5. You should see variables "mqttTarget" and "mqttTopic" in your newly created device.
6. Set the topic you want to subcribe to and the target (format: service,variable=(formula in LUA)).
7. Reload LUUP engine.

If the payload of the received message is in JSON, the plugin will try to decode it and put it in the variable "payload" in the context of the LUA formula.

Topic  : Test/#
Target: urn:upnp-org:serviceId:SwitchPower1,Status=payload.value and ((payload.value=="alarm") and "1" or "0")

On a message from topic 'Test/Something' with payload '{"value":"alarm"}', the switch will be powered on.

Topic  : Test/+/Sensor
Target: urn:upnp-org:serviceId:TemperatureSensor1,CurrentTemperature=payload.temperature and (tonumber(payload.temperature) or "0")

On a message from topic 'Test/Something/Sensor' with payload "{"temperature ":"15.2", "hygrometry":"80"}", the temperature will be set to 15,2.