ESP8266 Community Forum

- Sat Oct 31, 2015 2:24 am #32661 i'm having a problem with the code below when i execute it line by line it works fine but when i click "save to esp" it shows that error "init.lua:29: not connected"
code
--
wifi.setmode(wifi.STATION)
wifi.sta.config("IOTsMartHome","12345678")
ip = wifi.sta.getip()
print(ip)
--init mqtt client with keepalive timer 120sec
m = mqtt.Client("clientid", 120, "user", "password")

--setup Last Will and Testament (optional)
--Broker will publish a message with qos = 0, retain = 0, data = "offline"
--to topic "/lwt" if client don’t send keepalive packet
m:lwt("/lwt", "offline", 0, 0)

m:on("connect", function(con) print ("connected") end)
m:on("offline", function(con) print ("offline") end)


--on publish message receive event
m:on("message", function(conn, topic, data)
print(topic .. ":" )
if data ~= nil then
print(data)
end
end)
--for secure: m:connect("192.168.11.118", 1880, 1)
m:connect("192.168.1.6", 1883, 0, function(conn) print("connected") end)

--subscribe topic with qos = 0
m:subscribe("/call",0, function(conn) print("subscribe success") end)

--publish a message with data = hello, QoS = 0, retain = 0
m:publish("/topic","hello",0,0, function(conn) print("sent") end)

m:close();
--you can call m:connect again
--

- Sun Nov 01, 2015 6:07 pm #32783 I'd guess that your script contains a race condition which is triggered when being executed directly on the ESP. You should ensure that m:subscribe() and m:publish() aren't called before m:connect() did its job. Executing it line by line simply resolves the race for connecting in time.

Just put them into the callback function similar to this:

Code: Select all...
m:connect("192.168.1.6", 1883, 0, function(conn)
    print("connected")

    --subscribe topic with qos = 0
    m:subscribe("/call",0, function(conn) print("subscribe success") end)

    --publish a message with data = hello, QoS = 0, retain = 0
    m:publish("/topic","hello",0,0, function(conn) print("sent") end)
end)
...


It's generally good practice to stack dependant functionality in such way and to not rely on delays or polling loops.