На свежепрошитый чип я залил следующие файлы:

-- file : config.lua
local module = {}

module.SSID = {}  
module.SSID["xxxxx xxxxxxx"] = "xxxxxxxxxxxxxxxxx"

module.HOST = "mqtt.xxxxxxxxxxx.com"  
module.PORT = 1883  
module.ID = node.chipid()

module.ENDPOINT = "nodemcu/"  
return module  

-- file: setup.lua
local module = {}

local function wifi_wait_ip()  
  if wifi.sta.getip()== nil then
    print("IP unavailable, Waiting...")
  else
    tmr.stop(1)
    print("\n====================================")
    print("ESP8266 mode is: " .. wifi.getmode())
    print("MAC address is: " .. wifi.ap.getmac())
    print("IP is "..wifi.sta.getip())
    print("====================================")   
    app.start()
  end
end

local function wifi_start(list_aps)  
    if list_aps then
        for key,value in pairs(list_aps) do
            if config.SSID and config.SSID[key] then
                wifi.setmode(wifi.STATION);
                wifi.sta.config(key,config.SSID[key])
                wifi.sta.connect()
                print("Connecting to " .. key .. " ...")
                --config.SSID = nil  -- can save memory
                tmr.alarm(1, 2500, 1, wifi_wait_ip)
            end
        end
    else
        print("Error getting AP list")
    end
end

function module.start()  
  print("Configuring Wifi ...")
  wifi.setmode(wifi.STATION);
  wifi.sta.getap(wifi_start)
end

return module  


-- file : application.lua
local module = {}  
m = nil

-- Sends a simple ping to the broker
local function send_ping()  
    m:publish(config.ENDPOINT .. "ping","id=" .. config.ID,0,0)
end

-- Sends my id to the broker for registration
local function register_myself()  
    m:subscribe(config.ENDPOINT .. config.ID,0,function(conn)
        print("Successfully subscribed to data endpoint")
    end)
end

local function mqtt_start()  
    m = mqtt.Client(config.ID, 120)
    -- register message callback beforehand
    m:on("message", function(conn, topic, data) 
      if data ~= nil then
        print(topic .. ": " .. data)
        -- do something, we have received a message
      end
    end)
    -- Connect to broker
    m:connect(config.HOST, config.PORT, 0, 1, function(con) 
        register_myself()
        -- And then pings each 1000 milliseconds
        tmr.stop(6)
        tmr.alarm(6, 1000, 1, send_ping)
    end) 

end

function module.start()  
  mqtt_start()
end

return module  



-- file : test.lua
app = require("application")  
config = require("config")  
setup = require("setup")

setup.start()

Я отправил команду dofile("test.lua");

а я получаю......