diff --git a/app/modules/net.c b/app/modules/net.c
index 7fd785ab..dbd072f1 100644
--- a/app/modules/net.c
+++ b/app/modules/net.c
@@ -1119,7 +1119,6 @@ static int net_dns( lua_State* L, const char* mt )
   return 0;  
 }
 
-
 // Lua: s = net.createServer(type, function(server))
 static int net_createServer( lua_State* L )
 {
@@ -1284,6 +1283,55 @@ static int net_socket_dns( lua_State* L )
   return net_dns(L, mt);
 }
 
+static int net_multicastJoinLeave( lua_State *L, int join)
+{
+	  size_t il;
+	  ip_addr_t multicast_addr;
+	  ip_addr_t if_addr;
+	  const char *multicast_ip;
+	  const char *if_ip;
+
+	  NODE_DBG("net_multicastJoin is called.\n");
+	  if(! lua_isstring(L,1) ) return luaL_error( L, "wrong arg type" );
+	  if_ip = luaL_checklstring( L, 1, &il );
+	  if (if_ip != NULL)
+		 if ( if_ip[0] == '\0' || stricmp(if_ip,"any") == 0)
+	     {
+			 if_ip = "0.0.0.0";
+			 il = 7;
+	     }
+	  if (if_ip == NULL || il > 15 || il < 7) return luaL_error( L, "invalid if ip" );
+	  if_addr.addr = ipaddr_addr(if_ip);
+
+	  if(! lua_isstring(L,2) ) return luaL_error( L, "wrong arg type" );
+	  multicast_ip = luaL_checklstring( L, 2, &il );
+	  if (multicast_ip == NULL || il > 15 || il < 7) return luaL_error( L, "invalid multicast ip" );
+	  multicast_addr.addr = ipaddr_addr(multicast_ip);
+	  if (join)
+	  {
+		  espconn_igmp_join(&if_addr, &multicast_addr);
+	  }
+	  else
+	  {
+		  espconn_igmp_leave(&if_addr, &multicast_addr);
+	  }
+	  return 0;
+}
+// Lua: net.multicastJoin(ifip, multicastip)
+// if ifip "" or "any" all interfaces are affected
+static int net_multicastJoin( lua_State* L )
+{
+	return net_multicastJoinLeave(L,1);
+}
+
+// Lua: net.multicastLeave(ifip, multicastip)
+// if ifip "" or "any" all interfaces are affected
+static int net_multicastLeave( lua_State* L )
+{
+	return net_multicastJoinLeave(L,0);
+}
+
+
 #if 0
 static int net_array_index( lua_State* L )
 {
@@ -1358,6 +1406,8 @@ const LUA_REG_TYPE net_map[] =
 {
   { LSTRKEY( "createServer" ), LFUNCVAL ( net_createServer ) },
   { LSTRKEY( "createConnection" ), LFUNCVAL ( net_createConnection ) },
+  { LSTRKEY( "multicastJoin"), LFUNCVAL( net_multicastJoin ) },
+  { LSTRKEY( "multicastLeave"), LFUNCVAL( net_multicastLeave ) },
 #if LUA_OPTIMIZE_MEMORY > 0
   { LSTRKEY( "TCP" ), LNUMVAL( TCP ) },
   { LSTRKEY( "UDP" ), LNUMVAL( UDP ) },
diff --git a/app/modules/tmr.c b/app/modules/tmr.c
index 1a0fa478..ee92f4d5 100644
--- a/app/modules/tmr.c
+++ b/app/modules/tmr.c
@@ -71,6 +71,12 @@ static int tmr_delay( lua_State* L )
   us = luaL_checkinteger( L, 1 );
   if ( us <= 0 )
     return luaL_error( L, "wrong arg range" );
+  if(us<1000000)
+  {
+    os_delay_us( us );
+    WRITE_PERI_REG(0x60000914, 0x73);
+    return 0;
+  }  
   unsigned sec = (unsigned)us / 1000000;
   unsigned remain = (unsigned)us % 1000000;
   int i = 0;
diff --git a/examples/fragment.lua b/examples/fragment.lua
index 67aa2c37..fc426326 100644
--- a/examples/fragment.lua
+++ b/examples/fragment.lua
@@ -14,7 +14,7 @@ sk:connect(80,"115.239.210.27")
 sk:send("GET / HTTP/1.1\r\nHost: 115.239.210.27\r\nConnection: keep-alive\r\nAccept: */*\r\n\r\n")
 
 sk:connect(80,"192.168.0.66") 
-sk:send("GET / HTTP/1.1\r\nHost: 1192.168.0.66\r\nConnection: keep-alive\r\nAccept: */*\r\n\r\n")
+sk:send("GET / HTTP/1.1\r\nHost: 192.168.0.66\r\nConnection: keep-alive\r\nAccept: */*\r\n\r\n")
 
 i2c.setup(0,1,0,i2c.SLOW)
 function read_bmp(addr) i2c.start(0) i2c.address(0,119,i2c.RECEIVER) c=i2c.read(0,1) i2c.stop(0) print(string.byte(c)) end 
diff --git a/lua_modules/dht22/README.md b/lua_modules/dht22/README.md
index b68a3278..ab7b30f9 100644
--- a/lua_modules/dht22/README.md
+++ b/lua_modules/dht22/README.md
@@ -1,46 +1,78 @@
-# DHT22 module
+# DHTxx module
 
-This module is compatible with DHT22 and DHT21.  
-Supports nodemcu with or without floating point.  
+This module is compatible with DHT11, DHT21 and DHT22.  
 No need to use a resistor to connect the pin data of DHT22 to ESP8266.
 
-## Example  
+##Integer Verison[When using DHT11, Float version is useless...]
+### Example  
 ```lua
 PIN = 4 --  data pin, GPIO2
 
-dht22 = require("dht22")
-dht22.read(PIN)
-t = dht22.getTemperature()
-h = dht22.getHumidity()
+DHT= require("dht_lib")
+
+--dht.read11(PIN)
+DHT.read22(PIN)
+
+t = DHT.getTemperature()
+h = DHT.getHumidity()
 
 if h == nil then
-  print("Error reading from DHT22")
+  print("Error reading from DHT11/22")
 else
   -- temperature in degrees Celsius  and Farenheit
-  -- floating point and integer version:
+
   print("Temperature: "..((t-(t % 10)) / 10).."."..(t % 10).." deg C")
-  -- only integer version:
+
   print("Temperature: "..(9 * t / 50 + 32).."."..(9 * t / 5 % 10).." deg F")
-  -- only float point version:
-  print("Temperature: "..(9 * t / 50 + 32).." deg F")
   
   -- humidity
-  -- floating point and integer version
+
   print("Humidity: "..((h - (h % 10)) / 10).."."..(h % 10).."%")
 end
 
 -- release module
-dht22 = nil
-package.loaded["dht22"]=nil
+DHT = nil
+package.loaded["dht_lib"]=nil
+```
+##Float Verison
+###Example
+```lua
+PIN = 4 --  data pin, GPIO2
+
+DHT= require("dht_lib")
+
+--dht.read11(PIN)
+DHT.read22(PIN)
+
+t = DHT.getTemperature()
+h = DHT.getHumidity()
+
+if h == nil then
+  print("Error reading from DHT11/22")
+else
+  -- temperature in degrees Celsius  and Farenheit
+  -- floating point and integer version:
+  print("Temperature: "..t.." deg C")
+  print("Temperature: "..(9 * t / 50 + 32).." deg F")
+  
+  -- humidity
+  print("Humidity: "..h.."%")
+end
+
+-- release module
+DHT = nil
+package.loaded["dht_lib"]=nil
 ```
 ## Functions
-### read
-read(pin)  
-Read humidity and temperature from DHT22.
-
+### read11
+read11(pin)  
+Read humidity and temperature from DHT11.
+###read22
+read22(pin)
+Read humidity and temperature from DHT22/21.
 **Parameters:**
 
-* pin - ESP8266 pin connect to data pin in DHT22
+* pin - ESP8266 pin connect to data pin
 
 ### getHumidity
 getHumidity()  
@@ -54,5 +86,6 @@ getTemperature()
 Returns the temperature of the last reading.
 
 **Returns:**  
-* last temperature reading in 0.1ºC
+* last temperature reading in(dht22) 0.1ºC (dht11)1ºC
+* 
 
diff --git a/lua_modules/dht22/dht22.lua b/lua_modules/dht22/dht_lib.lua
similarity index 54%
rename from lua_modules/dht22/dht22.lua
rename to lua_modules/dht22/dht_lib.lua
index a80a1bd6..641f2e17 100644
--- a/lua_modules/dht22/dht22.lua
+++ b/lua_modules/dht22/dht_lib.lua
@@ -1,34 +1,43 @@
 -- ***************************************************************************
--- DHT22 module for ESP8266 with nodeMCU
+-- DHTxx(11,21,22) module for ESP8266 with nodeMCU
 --
--- Written by Javier Yanez 
+-- Written by Javier Yanez mod by Martin
 -- but based on a script of Pigs Fly from ESP8266.com forum
 --
 -- MIT license, http://opensource.org/licenses/MIT
 -- ***************************************************************************
 
+--Support list：
+--DHT11 Tested ->read11
+--DHT21 Not Tested->read22
+--DHT22 Tested->read22
+
+--==========================Module Part======================
 local moduleName = ...
 local M = {}
 _G[moduleName] = M
-
+--==========================Local the UMI and TEMP===========
 local humidity
 local temperature
+--==========================Local the bitStream==============
+local bitStream = {}
 
-function M.read(pin)
-  local checksum
-  local checksumTest
+---------------------------Read bitStream from DHTXX--------------------------
+local function read(pin)
+
+  local bitlength = 0
   humidity = 0
   temperature = 0
-  checksum = 0
 
   -- Use Markus Gritsch trick to speed up read/write on GPIO
   local gpio_read = gpio.read
   
-  local bitStream = {}
+  
   for j = 1, 40, 1 do
     bitStream[j] = 0
   end
-  local bitlength = 0
+
+  
 
   -- Step 1:  send out start signal to DHT22
   gpio.mode(pin, gpio.OUTPUT)
@@ -39,7 +48,7 @@ function M.read(pin)
   gpio.write(pin, gpio.HIGH)
   gpio.mode(pin, gpio.INPUT)
 
-  -- Step 2:  DHT22 send response signal 
+  -- Step 2:  Receive bitStream from DHT11/22
   -- bus will always let up eventually, don't bother with timeout
   while (gpio_read(pin) == 0 ) do end
   local c=0
@@ -59,8 +68,53 @@ function M.read(pin)
     -- bus will always let up eventually, don't bother with timeout
     while (gpio_read(pin) == 0) do end
   end
-
+end
+---------------------------Convert the bitStream into Number through DHT11 Ways--------------------------
+function M.read11(pin)
+--As for DHT11 40Bit is consisit of 5Bytes
+--First byte->Humidity Data's Int part
+--Sencond byte->Humidity Data's Float Part(Which should be empty)
+--Third byte->Temp Data;s Intpart
+--Forth byte->Temp Data's Float Part(Which should be empty)
+--Fifth byte->SUM Byte, Humi+Temp
+  read(pin)
+ local checksum = 0
+ local checksumTest
   --DHT data acquired, process.
+  for i = 1, 8, 1 do -- Byte[0]
+    if (bitStream[i] > 3) then
+      humidity = humidity + 2 ^ (8 - i)
+    end
+  end
+  for i = 1, 8, 1 do -- Byte[2]
+    if (bitStream[i + 16] > 3) then
+      temperature = temperature + 2 ^ (8 - i)
+    end
+  end
+  for i = 1, 8, 1 do --Byte[4]
+    if (bitStream[i + 32] > 3) then
+      checksum = checksum + 2 ^ (8 - i)
+    end
+  end
+
+  if(checksum ~= humidity+temperature) then
+    humidity = nil
+    temperature = nil
+  end
+  
+end
+---------------------------Convert the bitStream into Number through DHT22 Ways--------------------------
+function M.read22( pin )
+--As for DHT22 40Bit is consisit of 5Bytes
+--First byte->Humidity Data's High Bit
+--Sencond byte->Humidity Data's Low Bit(And if over 0x8000, use complement)
+--Third byte->Temp Data's High Bit
+--Forth byte->Temp Data's Low Bit
+--Fifth byte->SUM Byte
+  read(pin)
+  local checksum = 0
+  local checksumTest
+   --DHT data acquired, process.
   for i = 1, 16, 1 do
     if (bitStream[i] > 3) then
       humidity = humidity + 2 ^ (16 - i)
@@ -91,6 +145,7 @@ function M.read(pin)
   end
 end
 
+---------------------------Check out the data--------------------------
 function M.getTemperature()
   return temperature
 end
diff --git a/lua_modules/ds3231/ds3231.lua b/lua_modules/ds3231/ds3231.lua
index 48b0fd86..d13b89e8 100644
--- a/lua_modules/ds3231/ds3231.lua
+++ b/lua_modules/ds3231/ds3231.lua
@@ -16,11 +16,11 @@ local id = 0
 local dev_addr = 0x68
 
 local function decToBcd(val)
-  return((val/10*16) + (val%10))
+  return((((val/10) - ((val/10)%1)) *16) + (val%10))
 end
 
 local function bcdToDec(val)
-  return((val/16*10) + (val%16))
+  return((((val/16) - ((val/16)%1)) *10) + (val%16))
 end
 
 -- initialize i2c