ESP8266 Community Forum

Posted: **Mon Dec 29, 2014 4:56 pm**

Hello, all.
I have a strange problem.
This code suddenly stopped working since 0.9.4:

function sendData()
    sk=net.createConnection(net.TCP, 0)
    sk:on("receive", function(sck, c) print(c) end )
    sk:connect(8888, "192.168.11.1")
    sk:send("asdf jklo asa ads das")
    sk:close()
end
sendData()

When I am writing each line one-by-one, after the sk:close() the packet is sent.
However, when I call the function and do it quickly, the packet is not sent.
I cannot even receive an event on("connection", ...).
The same code worked with 0.9.2, the data within sk:send were transmitted imediatelly and I could use on("sent", ...) statement to close the connection.
Can anyone advice what am I doing wrong?
Thanks.

Posted: **Mon Dec 29, 2014 9:31 pm**

sancho wrote:Hello, all.
I have a strange problem.
This code suddenly stopped working since 0.9.4:
Code: Select allfunction sendData() sk=net.createConnection(net.TCP, 0) sk:on("receive", function(sck, c) print(c) end ) sk:connect(8888, "192.168.11.1") sk:send("asdf jklo asa ads das") sk:close() end sendData()

When I am writing each line one-by-one, after the sk:close() the packet is sent.
However, when I call the function and do it quickly, the packet is not sent.
I cannot even receive an event on("connection", ...).
The same code worked with 0.9.2, the data within sk:send were transmitted imediatelly and I could use on("sent", ...) statement to close the connection.
Can anyone advice what am I doing wrong?
Thanks.

connection close too fast?
maybe?

Code: Select all

sk:on("sent",function(sck) sck:close() end)
sk:send("hello")

Posted: **Tue Dec 30, 2014 1:42 am**

zeroday wrote:connection close too fast?
maybe?
Code: Select allsk:on("sent",function(sck) sck:close() end) sk:send("hello")

That was my first guess, but that's not the case - this on(„sent„,...) was the first version - again, the close part never gets executed.
I put some print statement into thevsent part and, again, never executed :-(

I must have had missed something :-(

Posted: **Tue Dec 30, 2014 7:15 am**

OK, to avoid confustion, this is the full script:

Code: Select all

pin = 4
ow.setup(pin)

function bxor(a,b)
   local r = 0
   for i = 0, 31 do
      if ( a % 2 + b % 2 == 1 ) then r = r + 2^i end
      a = a / 2
      b = b / 2
   end
   return r
end

function getTemp()
      print("Measurement start")
      sensors={}
      temps={}
      counter=0
      addr = ow.reset_search(pin)
      repeat
      tmr.wdclr()
      if (addr ~= nil) then
        crc = ow.crc8(string.sub(addr,1,7))
        if (crc == addr:byte(8)) then
          if ((addr:byte(1) == 0x10) or (addr:byte(1) == 0x28)) then
      sensor = ""
      for j = 1,7 do sensor = sensor .. string.format("%02x", addr:byte(j)) end
                print("Have sensor " .. sensor)
                sensors[counter] = sensor
                ow.reset(pin)
                ow.select(pin, addr)
                ow.write(pin, 0x44, 1)
                tmr.delay(1000 * 1000)
                present = ow.reset(pin)
                ow.select(pin, addr)
                ow.write(pin,0xBE, 1)
                data = nil
                data = string.char(ow.read(pin))
                for i = 1, 8 do data = data .. string.char(ow.read(pin)) end
                crc = ow.crc8(string.sub(data,1,8))
                if (crc == data:byte(9)) then
                   t = (data:byte(1) + data:byte(2) * 256)
         if (t > 32768) then
                    t = (bxor(t, 0xffff)) + 1
                    t = (-1) * t
                   end
         t = t * 625
                   if(addr:byte(1) == 0x10) then
                     -- we have DS18S20, the measurement must change
                     t = t * 8;  -- compensating for the 9-bit resolution only
                     t = t - 2500 + ((10000 * (data:byte(8) - data:byte(7))) / data:byte(8))
                   end
                   print("Got temp: " .. t)
                   temps[counter] = t
                end
          end
        end
      end
      addr = ow.search(pin)
      counter = counter + 1
      until(addr == nil)

    srv=net.createConnection(net.TCP, 0)
    srv:connect(8888, "192.168.11.1")
    srv:on("connection", function(conn) 
                             print "We have connection"
                         end
                         )
    output = ""
    for i, sensorID in ipairs(sensors) do
        t1 = temps[i] / 10000
        t2 = (temps[i] >= 0 and temps[i] % 10000) or (10000 - temps[i] % 10000)
        output = output .. wifi.sta.getmac()
        output = output .."\t" .. sensorID .. "\t" .. t1 .. "." .. string.format("%04d", t2) .. "\n"
    end
    print("Sending: " .. output)
    srv:send(output)
    srv:on("sent",function(conn) 
                      print("Data sent")
                      conn:close()
                  end)
end

function checkIP()
    if wifi.sta.getip() ~= nil then
        tmr.stop(0)
        tmr.wdclr()
        print("Got IP")
        print(wifi.sta.getip())
        print("Starting Temp measurement")
        getTemp()
        tmr.alarm(0,30*1000, 1, getTemp)
    end
end

tmr.alarm(0, 2 * 1000, 1, checkIP)

The code correctly prints the sensors and temperatures, the whole output is OK, however it is never sent.
And the on("sent", ...) part is also never triggered.
Any suggestions?

ESP8266 Community Forum

Strange TCP communication problem

Strange TCP communication problem

Re: Strange TCP communication problem

Re: Strange TCP communication problem

Re: Strange TCP communication problem