ESP8266 - nodemcu - http.get() tut nicht wie erwartet

function user_wifi_init( ssid, password )

  wifi.setmode(wifi.STATION)

  wifi.sta.config(ssid,password)

  wifi.sta.autoconnect(0)

  wifi.sta.eventMonReg(wifi.STA_GOTIP, user_cb_wifi_got_ip, "state")

  wifi.sta.eventMonStart()

  wifi.sta.connect()

end

function user_cb_wifi_got_ip( prev_state )

  ip = wifi.sta.getip()

  if ( ip )

  then

    print ("Got Ip: " .. ip )

    status, temp, humi, temp_dec, humi_dec = dht.read(7)

    vdd = adc.readvdd33(0)

    print ("DTH Temp: " .. temp .. " Humidity: " .. humi .. " VDD: " .. vdd)

    user_http_get(temp, humi, vdd)

  else

    print ("No IP!!!")

  end

end

-- Sende Daten an thingspeak

function user_http_get(temp, humi, vdd)

  api_key="XXXXXXXXXXXXXXXX"

  host="http://api.thingspeak.com"

  url=host .. "/update?api_key=XXXXXXXXXXXXXXXXX&field1=" .. temp .. "&field2=" .. humi .. "&field3=" .. vdd 

  hdr = "Content-Type: text/plain\r\n"

  print ("Send: " .. url)

  http.get( url, hdr, user_http_get_cb( code, data ))

  print ("Done!")

end

-- Callback for http_get()

function user_http_get_cb ( code, data )

  print ("user_http_get_cb!")

  if (code == nil) then

    print("HTTP request failed.")

  else

    print("user_http_get_cb Code:" .. code .. " Data: " .. data)

    wifi.sta.disconnect()

    node.dsleep(10 * 1000000)

  end

  gpio.write(6,0)

end

print ("Start!!!")

gpio.mode(6,gpio.OUTPUT)

gpio.write(6,1)

user_wifi_init("XXXX.1","XXXXXXXXXXXXXX")

print ("Ende!!!")