MqTT in Wiser for KNX

[manos@dynamitec]

Hello Erwin,

I have a SpaceLynk (V1.3 FW 2.7.0) that I would like to use as MQTT client and publish data to a cloud platform here in Belgium "Eniris". This device will serve only the purpose of MQTT client.
Could you or anyone assist me with the MQTT client script to be able to publish data in a certain json structured format?

The format should be like mentioned in the link below:

https://wiki.eniris.be/wiki/publicinform...3A%20MQTT/

In short something like this:

Topic = 'standart1/rp_one_m/T/userid/' and then in the data packet the following
 

Code:

{
  "time" :  1661506491 , --In Unix format
  "extraTags" : {
    "subId" :  "T19"
  },
  "fields" : {
    "temperature_degC" :  16.76 --this must be the value of the KNX object as a float datatype towards the broker)
  }
}

I have tested the MQTT client script below and the connection with the broker is ok. And data is being published but not in the certain format sctructure their platform is expecting it.

Code:

if not broker then
  broker = 'mqtt.eniris.be'
 
  username = 'xxx'
  password = 'xxx'
 
  socket = require('socket')

  port = 1883

  function multiply(mult)
    return function(value)
      local num = tonumber(value)
      if num then
        return num * mult
      else
        return value
      end
    end
  end

  -- topic to object map
  mqtt_to_object = {
    ['Actual Temp/Hal A/S2'] = '4/0/1',
    ['Actual Temp/Hal B/S1'] = '4/0/2',
  }

  -- optional topic value conversion function
  --mqtt_to_object_conv = {
  --  ['in/topic1'] = multiply(100),
  --  ['in/topic2'] = multiply(0.01),
  --}

  -- object to topic map
  object_to_mqtt = {
    ['4/0/1'] = 'Actual Temp/Hal A/S2',
    ['4/0/2'] = 'Actual Temp/Hal B/S1',
  }

  datatypes = {}

  grp.sender = 'mq'
  require('socket')

  for addr, _ in pairs(object_to_mqtt) do
    local obj = grp.find(addr)
    if obj then
      datatypes[ addr ] = obj.datatype
    end
  end

  mclient = require('mosquitto').new()

  mclient.ON_CONNECT = function(res, ...)
    log('mqtt connect status', res, ...)

    if res then
      for topic, _ in pairs(mqtt_to_object) do
        mclient:subscribe(topic)
      end
    else
      mclient:disconnect()
    end
  end

  mclient.ON_MESSAGE = function(mid, topic, payload)
    local addr = mqtt_to_object[ topic ]
    if addr then
      local fn = mqtt_to_object_conv[ topic ]

      if fn then
        payload = fn(payload)
      end

      grp.write(addr, payload)
    end
  end

  mclient.ON_DISCONNECT = function(...)
    log('mqtt disconnect', ...)
    mclientfd = nil
  end

  function mconnect()
    local status, rc, msg, fd

    status, rc, msg = mclient:connect(broker, port)

    if not status then
      log('mqtt connect failed ' .. tostring(msg))
    end

    fd = mclient:socket()
    if fd then
      mclientfd = fd
    end
  end
 
--mclient:tls_insecure_set(true)
  mclient:login_set(username, password or '')
 
  mconnect()

  function publishvalue(event)
    -- message from us or client is not connected
    if event.sender == 'mq' or not mclientfd then
      return
    end

    local addr = event.dst
    local dpt = datatypes[ addr ]
    local topic = object_to_mqtt[ addr ]

    -- unknown object
    if not dpt or not topic then
      return
    end

    local value = busdatatype.decode(event.datahex, dpt)
    if value ~= nil then
      if type(value) == 'boolean' then
        value = value and 1 or 0
      end

      mclient:publish(topic, tostring(value))
    end
  end

  lbclient = require('localbus').new(1)
  lbclient:sethandler('groupwrite', publishvalue)

  lbclientfd = socket.fdmaskset(lbclient:getfd(), 'r')

  -- run timer every 5 seconds
  timer = require('timerfd').new(5)
  timerfd = socket.fdmaskset(timer:getfd(), 'r')
end

-- mqtt connected
if mclientfd then
  mclientfdset = socket.fdmaskset(mclientfd, mclient:want_write() and 'rw' or 'r')
  res, lbclientstat, timerstat, mclientstat =
      socket.selectfds(10, lbclientfd, timerfd, mclientfdset)
-- mqtt not connected
else
  res, lbclientstat, timerstat =
    socket.selectfds(10, lbclientfd, timerfd)
end

if mclientstat then
  if socket.fdmaskread(mclientstat) then
    mclient:loop_read()
  end

  if socket.fdmaskwrite(mclientstat) then
    mclient:loop_write()
  end
end

if lbclientstat then
  lbclient:step()
end

if timerstat then
  -- clear armed timer
  timer:read()

  if mclientfd then
    mclient:loop_misc()
  else
    mconnect()
  end
end

Thank you in advance for your responce.

Regards