diff --git a/README.md b/README.md
index 7a86bd924..f42bb8d17 100644
--- a/README.md
+++ b/README.md
@@ -7,8 +7,8 @@
 
 This library enables you to **send _and_ receive** infra-red signals on an [ESP8266 using the Arduino framework](https://github.com/esp8266/Arduino) using common 940nm IR LEDs and common IR receiver modules. e.g. TSOP{17,22,24,36,38,44,48}* etc.
 
-## v2.3.3 Now Available
-Version 2.3.3 of the library is now [available](https://github.com/markszabo/IRremoteESP8266/releases/latest). You can view the [Release Notes](ReleaseNotes.md) for all the significant changes.
+## v2.4.0 Now Available
+Version 2.4.0 of the library is now [available](https://github.com/markszabo/IRremoteESP8266/releases/latest). You can view the [Release Notes](ReleaseNotes.md) for all the significant changes.
 
 #### Upgrading from pre-v2.0
 Usage of the library slight changed at v2.0. You will need to change your usage to work with v2.0 and beyond. You can read more about the changes required on our [Upgrade to v2.0](https://github.com/markszabo/IRremoteESP8266/wiki/Upgrading-to-v2.0) page.
diff --git a/ReleaseNotes.md b/ReleaseNotes.md
index a9a923883..b0e1c891f 100644
--- a/ReleaseNotes.md
+++ b/ReleaseNotes.md
@@ -1,5 +1,23 @@
 # Release Notes
 
+## _v2.4.0 (20180407)_
+
+**[Bug Fixes]**
+- Add missing WiFi.begin() call to IRGCTCPServer example. (#433)
+- Add missing sendHaierAC() to IRMQTTServer example. (#434 & #444)
+- Make mqtt clientid unique in IRMQTTServer example. (#444)
+
+**[Features]**
+
+- Initial Mitsubishi projector protocol support. (#442)
+- Experimental support of Hitachi A/C messages. (#445)
+- Improve transmission pulse modulation support.
+  Allow disabling of transmission frequency modulation.(#439)
+
+**[Misc]**
+- IRMQTTServer example improvements. (#444)
+
+
 ## _v2.3.3 (20180302)_
 
 **[Bug Fixes]**
diff --git a/keywords.txt b/keywords.txt
index 02b3183e4..8e582aed7 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -41,6 +41,7 @@ match_result_t	KEYWORD1
 # Methods and Functions (KEYWORD2)
 #######################################
 
+_delayMicroseconds	KEYWORD2
 add	KEYWORD2
 addbit	KEYWORD2
 begin	KEYWORD2
@@ -67,6 +68,7 @@ decodeFujitsuAC	KEYWORD2
 decodeGree	KEYWORD2
 decodeHaierAC	KEYWORD2
 decodeHash	KEYWORD2
+decodeHitachiAC	KEYWORD2
 decodeJVC	KEYWORD2
 decodeKelvinator	KEYWORD2
 decodeLG	KEYWORD2
@@ -74,6 +76,7 @@ decodeLasertag	KEYWORD2
 decodeMagiQuest	KEYWORD2
 decodeMidea	KEYWORD2
 decodeMitsubishi	KEYWORD2
+decodeMitsubishi2	KEYWORD2
 decodeNEC	KEYWORD2
 decodeNikai	KEYWORD2
 decodePanasonic	KEYWORD2
@@ -156,6 +159,7 @@ getiFeel	KEYWORD2
 hasACState	KEYWORD2
 invertBits	KEYWORD2
 ledOff	KEYWORD2
+ledOn	KEYWORD2
 mark	KEYWORD2
 match	KEYWORD2
 matchAtLeast	KEYWORD2
@@ -187,6 +191,7 @@ sendGC	KEYWORD2
 sendGeneric	KEYWORD2
 sendGree	KEYWORD2
 sendHaierAC	KEYWORD2
+sendHitachiAC	KEYWORD2
 sendJVC	KEYWORD2
 sendKelvinator	KEYWORD2
 sendLG	KEYWORD2
@@ -194,6 +199,7 @@ sendLasertag	KEYWORD2
 sendMagiQuest	KEYWORD2
 sendMidea	KEYWORD2
 sendMitsubishi	KEYWORD2
+sendMitsubishi2	KEYWORD2
 sendMitsubishiAC	KEYWORD2
 sendNEC	KEYWORD2
 sendNikai	KEYWORD2
@@ -392,6 +398,7 @@ DECODE_GLOBALCACHE	LITERAL1
 DECODE_GREE	LITERAL1
 DECODE_HAIER_AC	LITERAL1
 DECODE_HASH	LITERAL1
+DECODE_HITACHI_AC	LITERAL1
 DECODE_JVC	LITERAL1
 DECODE_KELVINATOR	LITERAL1
 DECODE_LASERTAG	LITERAL1
@@ -399,6 +406,7 @@ DECODE_LG	LITERAL1
 DECODE_MAGIQUEST	LITERAL1
 DECODE_MIDEA	LITERAL1
 DECODE_MITSUBISHI	LITERAL1
+DECODE_MITSUBISHI2	LITERAL1
 DECODE_MITSUBISHI_AC	LITERAL1
 DECODE_NEC	LITERAL1
 DECODE_NIKAI	LITERAL1
@@ -451,6 +459,7 @@ DISH_TICK	LITERAL1
 DISH_ZERO_SPACE	LITERAL1
 DISH_ZERO_SPACE_TICKS	LITERAL1
 DUTY_DEFAULT	LITERAL1
+DUTY_MAX	LITERAL1
 FNV_BASIS_32	LITERAL1
 FNV_PRIME_32	LITERAL1
 FOOTER	LITERAL1
@@ -573,6 +582,15 @@ HAIER_AC_SWING_UP	LITERAL1
 HAIER_AC_ZERO_SPACE	LITERAL1
 HEADER	LITERAL1
 HIGH	LITERAL1
+HITACHI_AC	LITERAL1
+HITACHI_AC_BITS	LITERAL1
+HITACHI_AC_BIT_MARK	LITERAL1
+HITACHI_AC_HDR_MARK	LITERAL1
+HITACHI_AC_HDR_SPACE	LITERAL1
+HITACHI_AC_MIN_GAP	LITERAL1
+HITACHI_AC_ONE_SPACE	LITERAL1
+HITACHI_AC_STATE_LENGTH	LITERAL1
+HITACHI_AC_ZERO_SPACE	LITERAL1
 ICACHE_RAM_ATTR	LITERAL1
 JVC	LITERAL1
 JVC_BITS	LITERAL1
@@ -728,6 +746,12 @@ MIN_LASERTAG_SAMPLES	LITERAL1
 MIN_RC5_SAMPLES	LITERAL1
 MIN_RC6_SAMPLES	LITERAL1
 MITSUBISHI	LITERAL1
+MITSUBISHI2	LITERAL1
+MITSUBISHI2_BIT_MARK	LITERAL1
+MITSUBISHI2_HDR_SPACE	LITERAL1
+MITSUBISHI2_MIN_GAP	LITERAL1
+MITSUBISHI2_ONE_SPACE	LITERAL1
+MITSUBISHI2_ZERO_SPACE	LITERAL1
 MITSUBISHI_AC	LITERAL1
 MITSUBISHI_AC_AUTO	LITERAL1
 MITSUBISHI_AC_BIT_MARK	LITERAL1
@@ -737,6 +761,7 @@ MITSUBISHI_AC_FAN_AUTO	LITERAL1
 MITSUBISHI_AC_FAN_MAX	LITERAL1
 MITSUBISHI_AC_FAN_REAL_MAX	LITERAL1
 MITSUBISHI_AC_FAN_SILENT	LITERAL1
+MITSUBISHI_AC_HDR_MARK	LITERAL1
 MITSUBISHI_AC_HDR_SPACE	LITERAL1
 MITSUBISHI_AC_HEAT	LITERAL1
 MITSUBISHI_AC_MAX_TEMP	LITERAL1
@@ -918,6 +943,7 @@ SEND_FUJITSU_AC	LITERAL1
 SEND_GLOBALCACHE	LITERAL1
 SEND_GREE	LITERAL1
 SEND_HAIER_AC	LITERAL1
+SEND_HITACHI_AC	LITERAL1
 SEND_JVC	LITERAL1
 SEND_KELVINATOR	LITERAL1
 SEND_LASERTAG	LITERAL1
@@ -925,6 +951,7 @@ SEND_LG	LITERAL1
 SEND_MAGIQUEST	LITERAL1
 SEND_MIDEA	LITERAL1
 SEND_MITSUBISHI	LITERAL1
+SEND_MITSUBISHI2	LITERAL1
 SEND_MITSUBISHI_AC	LITERAL1
 SEND_NEC	LITERAL1
 SEND_NIKAI	LITERAL1
diff --git a/library.json b/library.json
index cbdb23f1c..5bd8d2e62 100644
--- a/library.json
+++ b/library.json
@@ -1,6 +1,6 @@
 {
   "name": "IRremoteESP8266",
-  "version": "2.3.3",
+  "version": "2.4.0",
   "keywords": "infrared, ir, remote, esp8266",
   "description": "Send and receive infrared signals with multiple protocols (ESP8266)",
   "repository":
diff --git a/library.properties b/library.properties
index 3b1b4082d..959eee82e 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=IRremoteESP8266
-version=2.3.3
+version=2.4.0
 author=Sebastien Warin, Mark Szabo, Ken Shirriff, David Conran
 maintainer=Mark Szabo, David Conran, Sebastien Warin, Roi Dayan, Massimiliano Pinto
 sentence=Send and receive infrared signals with multiple protocols (ESP8266)
diff --git a/src/IRremoteESP8266.h b/src/IRremoteESP8266.h
index 01b532ce8..d4806f7d5 100644
--- a/src/IRremoteESP8266.h
+++ b/src/IRremoteESP8266.h
@@ -48,7 +48,7 @@
 #endif
 
 // Library Version
-#define _IRREMOTEESP8266_VERSION_ "2.3.3"
+#define _IRREMOTEESP8266_VERSION_ "2.4.0"
 // Supported IR protocols
 // Each protocol you include costs memory and, during decode, costs time
 // Disable (set to false) all the protocols you do not need/want!