Geeknesia

Pada tutorial ini, akan dicoba melakukan pengiriman action control menggunakan protocol MQTT kepada modul ESP8266.

Sample code ESP8266

 init.lua

-- Constants
SSID    = "Your SSID"
APPWD   = "Password"

-- File that is executed after connection
CMDFILE = "mqtt.lua"

-- Some control variables
wifiTrys     = 0      -- Counter of trys to connect to wifi
NUMWIFITRYS  = 200    -- Maximum number of WIFI Testings while waiting for connection

-- Change the code of this function that it calls your code.
function launch()
  print("Connected to WIFI!")
  print("IP Address: " .. wifi.sta.getip())

-- Call our command file every minute.
  tmr.alarm(0, 1000, 0, function() dofile(CMDFILE) end )
end

function checkWIFI() 
  if ( wifiTrys > NUMWIFITRYS ) then
    print("Sorry. Not able to connect")
  else
    ipAddr = wifi.sta.getip()
    if ( ( ipAddr ~= nil ) and  ( ipAddr ~= "0.0.0.0" ) )then
      -- lauch()        -- Cannot call directly the function from here the timer... NodeMcu crashes...
      tmr.alarm( 1 , 500 , 0 , launch )
    else
      -- Reset alarm again
      tmr.alarm( 0 , 2500 , 0 , checkWIFI)
      print("Checking WIFI..." .. wifiTrys)
      wifiTrys = wifiTrys + 1
    end 
  end 
end

print("-- Starting up! ")

-- Lets see if we are already connected by getting the IP
ipAddr = wifi.sta.getip()
if ( ( ipAddr == nil ) or  ( ipAddr == "0.0.0.0" ) ) then
-- We aren't connected, so let's connect
  print("Configuring WIFI....")
  wifi.setmode( wifi.STATION )
  wifi.sta.config( SSID , APPWD)
  print("Waiting for connection")
  tmr.alarm( 0 , 2500 , 0 , checkWIFI )  -- Call checkWIFI 2.5S in the future.
else
-- We are connected, so just run the launch code.
 launch()
end
-- Drop through here to let NodeMcu run

File init.lua ini merupakan script penting dari project ini, karena script ini berfungsi untuk menghubungkan ESP8266-12 ke server dengan men-setting SSID Wifi dan Password Wifi yang anda gunakan.

  

mqtt.lua 

m = mqtt.Client("device-8d7dc14bf6cf01xxxxxxx",120,"user","password") 
 
--inisialisasi pin (gpio) 
pin=2 
gpio.mode(pin,gpio.OUTPUT) 
gpio.write(pin,gpio.HIGH) 
 
--Fungsi di bawah ini berfugsi untuk mengkonekkan device ke ip 
geeknesia.com 
function connect() 
 m:connect("geeknesia.com", 1883, 0, function(conn) 
   print("connected") 
   m:lwt("iot/will", "device-8d7dc14bf6cf01xxxxxx", 0, 0) 
   m:subscribe("topic-8d7dc14bf6cf010dxxxxxx",0, function(conn) 
     print("subscribe success") 
   end) 
end) 
 
print("selesai connect") 
end 
connect() 
 
--Script dibawah bertujuan supaya jika koneksi terputus maka akan auto 
reconnect 
m:on("offline", function(conn) 
  print("Reconnect" ) 
  connect() 
end) 
 
--Pesan yang diterima dari topic yang di subscribe 
--Jika Esp-12 menerima “on” maka pin akan HIGH dan sebaliknya jika 
menerima  
--“off” maka pin akan LOW (Tergantung Wiring Esp ke led) 
m:on("message", function(conn, topic, data) 
  print(topic .. ":" ) 
  if data ~= nil then 
    print(data) 
     if data=="on" then 
       gpio.write(2, gpio.HIGH)
     end 
     if data=="off" then 
       gpio.write(2, gpio.LOW) 
     end 
  end 
end)