ESP8266 Community Forum

Hi there,

I'm a newbie to LUA and ESP8266. I've written below code to create a socket, read the date & time from a server, convert format and store in a global variable dateRcv. The code ran ok to get date and time. However, it can never return from the function gettime() that created the socket. If I add timer loop after gettime() is called, the program seemed to have crashed and exit.

Can someone helped me and pointed me to the right direction? Many thanks!



Output:
Get IP address status: 5
DNS server: 58.176.125.223
> Received data 29 OCT 2015 10:48:23 UTC

Date, time: 15-10-29 10:48:23

Disconnecting...

Sunny wrote:Hi there,

I'm a newbie to LUA and ESP8266. I've written below code to create a socket, read the date & time from a server, convert format and store in a global variable dateRcv. The code ran ok to get date and time. However, it can never return from the function gettime() that created the socket. If I add timer loop after gettime() is called, the program seemed to have crashed and exit.

Can someone helped me and pointed me to the right direction? Many thanks!

Code: Select allportno = 13
tcpserverip = "ptbtime2.ptb.de"  -- "ptbtime1.ptb.de"
SSID = "TEST"
pwd = "1234abcd"
dateRcv = ""
starttime = tmr.time()

wifi.setmode(wifi.STATION)
wifi.sta.config(SSID,pwd)
wifi.sta.connect()
repeat
    tmr.alarm(0, 1000, 0, function() end)
    print("Get IP address status: ", wifi.sta.status())
until wifi.sta.status() >= 2
if wifi.sta.status() >=2 then
    net.dns.setdnsserver("58.176.125.223",0)
    print("DNS server: ", net.dns.getdnsserver(0))
end

function gettime(port, TSip)
    local mt = {JAN=1,FEB=2,MAR=3,APR=4,MAY=5,JUN=6,JUL=7,AUG=8,SEP=9,OCT=10,NOV=11,DEC=12}
    local time = ""
    local gotdate = false
    if (wifi.sta.getip() ~= nil) then       
        sk = net.createConnection(net.TCP, 0) 
       
        sk:on("receive", function(sk, payload)
            print("Received data "..payload)
            m = (mt[string.sub(payload, 4, 6)])
            dateRcv = string.sub(payload, 10,11) .. "-"..m .."-".. string.sub(payload, 1, 2)
            time = string.sub(payload, 13, 20)
            print("Date, time: ", dateRcv, time, "\n")
            gotdate = true
            sk:close()
        end)

        sk:connect(portno, tcpserverip)
        sk:on("connection",function(sk, payload)
              sk:send(" ")
        end)

        sk:on("disconnection",function(sk)
            sk=nil
            print("Disconnecting...")
            collectgarbage()
        end )
    else
        print("Failed to connect. Stopped retry!")
    end
  return
end
--
gettime(portno, tcpserverip)
--[[  remove below comment block will allow function to exit but
      dateRcv can't be retrived.
repeat
   tmr.alarm(0, 1000, 0, function() end)
until dateRcv ~= ""
print("Date Received: ", dateRcv)
-]]


Output:
Get IP address status: 5
DNS server: 58.176.125.223
> Received data 29 OCT 2015 10:48:23 UTC

Date, time: 15-10-29 10:48:23

Disconnecting...

----------
Hi there,

I've my problem fixed. I changed the repeat loop with the tmr.alarm to a the repeat mode. The gettime function is called only when wifi.sta.getip() ~= nil. Other functions are then triggered by the "receive" event. With that, the program runs ok.

Unfortunately, when I tried to add in other functionalities, the LUA compiler flags not enough memory. I might have stretched the nodemcu capability too much. So I have decided to move to the ESP8266 SDK and develop under "C".

Thanks!
Sunny