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MQTT subscribe
#1
Hello,

I'm trying to subscribe to a MQTT topic ("arqueta/humedad") and asign his value to an object of logic machine.

I'm using de test Mosquitto broker and I publish previously a value to the topic "arqueta/humedad".

I'm using this code (extracted from here) as a resident script but It seems doesn't works and I don't know what I'm doing wrong...

Code:
-- Define a function which is called by mqtt_client:handler(),
-- whenever messages are received on the subscribed topics

    function callback(topic, message)
    print("Received: " .. topic .. ": " .. message)
    if (message == "quit") then running = false end
  end

-- Create an MQTT client instance, connect to the MQTT server and
-- subscribe to the topic called "arqueta/humedad"

    MQTT = require("mosquitto")
  MQTT.Utility.set_debug(true)
    mqtt_client = MQTT.client.create("https://test.mosquitto.org", 1883, callback)
    mqtt_client:connect("logicmachine")
    local humedad = mqtt_client:subscribe("arqueta/humedad")
    grp.update('1/1/27', humedad)


-- Continously invoke mqtt_client:handler() to process the MQTT protocol and
-- handle any received messages.  Also, publish a message on topic "test/1"

  running = true

  while (running) do
    mqtt_client:handler()
    mqtt_client:publish("test/1", "test message")
    socket.sleep(1.0)  -- seconds
  end

-- Clean-up by unsubscribing from the topic and closing the MQTT connection

  mqtt_client:unsubscribe({"arqueta/humedad"})
  mqtt_client:destroy()
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#2
Upgrade firmware to 2018 RC1. It has built-in MQTT library support and some other features required for this script.

Create resident script with 0 sleep interval. Change broker IP address and mapping tables as needed.
mqtt_to_object maps topic to a group address, object_to_mqtt maps group address to atopic.

Do full script restart via disable/enable when changing any mapping tables and/or broker address.

Code:
if not broker then
  broker = '192.168.1.101'

  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 = {
    ['in/topic1'] = '32/1/1',
    ['in/topic2'] = '32/1/2',
  }

  -- 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 = {
    ['1/1/1'] = 'out/topic1',
    ['1/1/2'] = 'out/topic2',
  }

  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 fd

    mclient:connect(broker)
    fd = mclient:socket()

    -- fd ref is valid
    if fd then
      mclientfd = fd
    end
  end

  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 mclientfd and 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
Reply
#3
(03.12.2018, 08:43)admin Wrote: Upgrade firmware to 2018 RC1. It has built-in MQTT library support and some other features required for this script.

Create resident script with 0 sleep interval. Change broker IP address and mapping tables as needed.
mqtt_to_object maps topic to a group address, object_to_mqtt maps group address to atopic.

Do full script restart via disable/enable when changing any mapping tables and/or broker address.

I'm trying to do this but it doesn't works. I supose that when I send a value to the broker, automatically the script must receive the value? 

I've just upgrade the firmware. Here's the actual version:

[Image: firmware.png]

Here's my code where I put the mosquitto test broker and the topic "arqueta/humedad" I'm testing. the object 32/1/1 is a "05. 1 byte unsigned integer".

As I say, it doesn't works and I don't know what I'm doing wroing.

The correct line to broker is without "http://"

broker = 'test.mosquitto.org'

Now it works the suscribe.
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#4
Hi!

I have problem with object_to_mqtt this topic will change on MQTT when I write new value? Is it necessary event script? Now I don't see change this value on client.
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#5
No event script is needed. Value is published to selected topic when value changes. Have you checked that MQTT client is connected? Does the reverse (mqtt_to_object) work? Does the client have access to the select topic?
You can log the publish result like this (line 83):
Code:
local r, e, c = mclient:publish(topic, tostring(value))
log('publish', r, e, c)
Reply
#6
Solved! the problem was client software that I used, MQTT_to_object worked but no the reverse.
Reply
#7
Admin thank you for this code!, it works great.

But how can i apply a scale factor to one of the "mqtt_to_object"?
Reply
#8
I've updated example post. Edit mqtt_to_object_conv table as needed, custom conversion functions can be added as well.
Reply
#9
(09.03.2020, 08:46)admin Wrote: I've updated example post. Edit mqtt_to_object_conv table as needed, custom conversion functions can be added as well.

Hi,
in my case am using LM as broker and i need to Publish/subscribe single topic Message payloads to different group address?


how to achieve below criteria in LM5

ex: for  relay-1 is 0/0/1 as group address  
topic=100
Payload on=C,1,1,\r\n
Payload off =C,1,0,\r\n

for relay-2 is 0/0/2 as group address 
topic=100
Payload on=C,2,1,\r\n
Payload off=C,2,0,\r\n
Reply
#10
Add custom logic to the MQTT callbacks:
Code:
mclient.ON_CONNECT = function(res, ...)
  log('mqtt connect status', res, ...)

  if res then
    mclient:subscribe('100')
  else
    mclient:disconnect()
  end
end

mclient.ON_MESSAGE = function(mid, topic, payload)
  if topic == '100' then
    if payload == "C,1,1,\r\n" then
      grp.write('0/0/1', true)
    elseif payload == "C,1,0,\r\n" then
      grp.write('0/0/1', false)
    elseif payload == "C,2,1,\r\n" then
      grp.write('0/0/2', true)
    elseif payload == "C,2,0,\r\n" then
      grp.write('0/0/2', false)
    end
  end
end

Using one topic for controlling multiple entities is bad system design. Each relay should have it's own topic for control if possible.
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#11
Hi,
please elaborate this custom Logic in Mqtt callbacks where we can i find
actually am adding this logic in main residence script please find it in attached file(how we have done)
am doing it in correct way...?

Attached Files
.txt   Mqtt res-code_LM5.txt (Size: 3.53 KB / Downloads: 1)
Reply
#12
Looks correct, add logging for each received message in case it does not work:
Code:
mclient.ON_MESSAGE = function(mid, topic, payload)
  log(topic, payload)
  ...
end
Reply
#13
(22.02.2021, 07:24)admin Wrote: Looks correct, add logging for each received message in case it does not work:
Code:
mclient.ON_MESSAGE = function(mid, topic, payload)
  log(topic, payload)
  ...
end

Hi,

Please find attached snap shots of Logs

Attached Files Image(s)
       
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#14
Check the latest log entry, it shows what data was published to the topic named "100". Modify the ON_MESSAGE callback function to execute actions based on the received payload:
Code:
mclient.ON_MESSAGE = function(mid, topic, payload)
  log('ON_MESSAGE ', topic, payload)
  if topic == '100' then
    if payload == "11" then
      grp.write('0/0/1', true)
    elseif payload == "10" then
      grp.write('0/0/1', false)
   end
  end
end

You can use MQTT explorer (http://mqtt-explorer.com/) to connect to LM and send any data to any topics to test your scripts.
Reply
#15
alternatively you can use my declarative binding for mqtt2knx integration, although it was created for zigbee2mqtt topics
https://forum.logicmachine.net/showthread.php?tid=2671
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#16
Hi,
in this case the publishing topic=100, and Payload=C,1,1,1,\r\n like this format while subscribing topic=100 and msg Payload=$FD;2;4;0;0;0;0;0;0;@ while watching from LM log  we found this.

Attached Files Image(s)
   
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#17
Modify the example in my previous post and implement your custom actions based on the received payload value.
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