Connect ESP8266 to IBM IoT Foundation and publish data via MQTT (NodeMCU Firmware)

mainIoTF.lua

-- see https://developer.ibm.com/recipes/tutorials/connect-espressif-esp8266-to-ibm-iot-foundation/ for more information

orgID = "quickstart"  -- IoT Foundation organization ID replace this with your own after creating an IoT service in bluemix
broker = "quickstart.messaging.internetofthings.ibmcloud.com" -- IP or hostname of Quickstart IoTF service
mqttPort = 1883 -- MQTT port (default 1883)
userID = "" -- optional. Set to "use-token-auth" for token auth
userPWD = "" -- optional. Put token here for token auth
macID= wifi.sta.getmac():gsub('-','') -- set this manually if needed. Just hex digits, no collons/spaces/dashes/etc.
clientID = "d:quickstart:esp8266:"..macID -- Device ID
count = 0 -- Test number of mqtt_do cycles
mqttState = 0 -- State control

topic = "iot-2/evt/status/fmt/json"

t0 = tmr.time()

-- Wifi credentials
SSID = "<your wifi SSID>" -- <========== Modify this!
wifiPWD = "<your wifi password>" -- <========== Modify this!

function wifi_connect()
    wifi.setmode(wifi.STATION)
    wifi.sta.config(SSID,wifiPWD)
    wifi.sta.connect()
end

function mqtt_do()
    count = count + 1 -- tmr.alarm counter

    if mqttState < 5 then
       mqttState = wifi.sta.status() -- State: Waiting for wifi
       wifi_connect()

    elseif mqttState == 5 then
        print("Starting to connect...")
        m = mqtt.Client(clientID, 120, userID, userPWD)

        m:on("offline", function(conn)
            print ("Checking IoTF server...")
            mqttState = 0 -- Starting all over again
        end)

        m:connect(broker , mqttPort, 0,
            function(conn)
            print("Connected to " .. broker .. ":" .. mqttPort)
            if orgID == "quickstart" then
                print("Visit https://quickstart.internetofthings.ibmcloud.com/#/device/" .. macID .. "/sensor/ to see data")
            else
                print("MAC address is " .. macID);
            end
            mqttState = 20 -- Go to publish state
        end)

    elseif mqttState == 20 then
        mqttState = 25 -- Publishing…
        t1 = tmr.time() - t0
        if t1 > 100 then
           t1 = 0
           t0 = tmr.time()
       end
       m:publish(topic ,'{"d": {"data":'..t1..'}}', 0, 0, -- or use cjson module for more complex json
            function(conn)
            -- Print confirmation of data published
           print("Sent message #"..count.." data:"..t1)
           mqttState = 20 -- Finished publishing -- go back to publish state.
       end)

   else print("Waiting…"..mqttState)
        mqttState = mqttState - 1 -- takes us gradually back to publish state to retry
   end

end

tmr.alarm(2, 10000, 1, function() mqtt_do() end) -- send data every 10s