WiFiSwitch/init.lua

-- Constants
SSID    = "MessWLAN"
APPWD   = "UNVmpwbr6heQnMQ7ykXT"
CMDFILE = "mqtt.lua" 

-- Some control variables
wifiTrys     = 0    
NUMWIFITRYS  = 200 

function launch()
  print("A")
  print("B: " .. wifi.sta.getip())
  tmr.alarm(0, 5000, 0, function() dofile(CMDFILE) end )
end

function checkWIFI() 
  if ( wifiTrys > NUMWIFITRYS ) then
    print("C")
  else
    ipAddr = wifi.sta.getip()
    if ( ( ipAddr ~= nil ) and  ( ipAddr ~= "0.0.0.0" ) )then
      tmr.alarm( 1 , 500 , 0 , launch )
    else
      tmr.alarm( 0 , 2500 , 0 , checkWIFI)
      print("D: " .. wifiTrys)
      wifiTrys = wifiTrys + 1
    end 
  end 
end

print("E")

ipAddr = wifi.sta.getip()
if ( ( ipAddr == nil ) or  ( ipAddr == "0.0.0.0" ) ) then
  print("F")
  wifi.setmode( wifi.STATION )
  wifi.sta.config( SSID , APPWD)
  print("G")
  tmr.alarm( 0 , 2500 , 0 , checkWIFI )
else
 launch()
end