diff --git a/sonoff/_releasenotes.ino b/sonoff/_releasenotes.ino
index 79b1693d2..bfabfeed0 100644
--- a/sonoff/_releasenotes.ino
+++ b/sonoff/_releasenotes.ino
@@ -1,10 +1,11 @@
 /* 5.10.0b
- * Add optional support for PZEM004T energy sensor
+ * Add support for PZEM004T energy sensor to be enabled with define USE_PZEM004T in user_config.h
  * Change Sonoff Pow Energy MQTT data message and consolidate Status 8 into Status 10
  * Change Wemo SetBinaryState to distinguish from GetBinaryState (#1357)
- * Change output of HTTP command to valid JSON only (#1363)
- * Change output to valid JSON Array if needed (#1363)
- * Add support for sensor MH-Z19(B) to be enabled with define USE_MHZ19 in user_config.h (#561, #1248)
+ * Change output of HTTP command to valid JSON and Array only (#1363)
+ * Add support for MH-Z19(B) CO2 sensor to be enabled with define USE_MHZ19 in user_config.h (#561, #1248)
+ * Add support for senseair S8 CO2 sensor to be enabled with define USE_SENSEAIR in user_config.h
+ * Add support for Domoticz Air Quality sensor to be used by MH-Z19(B) and SenseAir sensors
  *
  * 5.10.0a
  * Add (experimental) support for sensor SHT3x
diff --git a/sonoff/i18n.h b/sonoff/i18n.h
index f7bebbbf8..3c3fd66be 100644
--- a/sonoff/i18n.h
+++ b/sonoff/i18n.h
@@ -1,7 +1,7 @@
 /*
   i18n.h - internationalization for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -121,6 +121,10 @@ const char HTTP_SNS_PRESSURE[] PROGMEM = "%s{s}%s " D_PRESSURE "{m}%s " D_UNIT_P
 const char HTTP_SNS_SEAPRESSURE[] PROGMEM = "%s{s}%s " D_PRESSUREATSEALEVEL "{m}%s " D_UNIT_PRESSURE "{e}";  // {s} = <tr><th>, {m} = </th><td>, {e} = </td></tr>
 const char HTTP_SNS_ANALOG[] PROGMEM = "%s{s}%s " D_ANALOG_INPUT "%d{m}%d{e}";                               // {s} = <tr><th>, {m} = </th><td>, {e} = </td></tr>
 
+#if defined(USE_MHZ19) || defined(USE_SENSEAIR)
+const char HTTP_SNS_CO2[] PROGMEM = "%s{s}%s " D_CO2 "{m}%d " D_UNIT_PPM "{e}";                              // {s} = <tr><th>, {m} = </th><td>, {e} = </td></tr>
+#endif  // USE_WEBSERVER
+
 const char S_MAIN_MENU[] PROGMEM = D_MAIN_MENU;
 const char S_CONFIGURATION[] PROGMEM = D_CONFIGURATION;
 const char S_CONFIGURE_MODULE[] PROGMEM = D_CONFIGURE_MODULE;
diff --git a/sonoff/language/de-DE.h b/sonoff/language/de-DE.h
index 8576b8ed1..18a7a5d61 100644
--- a/sonoff/language/de-DE.h
+++ b/sonoff/language/de-DE.h
@@ -1,7 +1,7 @@
 /*
   de-DE.h - localization for German - Germany for Sonoff-Tasmota
 
-  Copyright (C) 2017  VinceMasuka
+  Copyright (C) 2018  VinceMasuka
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -66,7 +66,7 @@
 #define D_BUTTON "Knopf"
 #define D_BY "von"                   // Written by me
 #define D_CELSIUS "Celsius"
-#define D_CO2 "CO2"
+#define D_CO2 "Kohlenstoffdioxid"
 #define D_CODE "code"                // Button code
 #define D_COLDLIGHT "kalt"
 #define D_COMMAND "Befehl"
@@ -118,6 +118,7 @@
 #define D_INITIALIZED "initialisiert"
 #define D_IP_ADDRESS "IP-Addresse"
 #define D_LIGHT "Licht"
+#define D_LIMIT "Grenzwert"
 #define D_LOCAL_TIME "lokale Zeit"
 #define D_LOW "niedrig"
 #define D_LWT "LWT"
@@ -386,6 +387,7 @@
   #define D_DOMOTICZ_COUNT "Count"
   #define D_DOMOTICZ_VOLTAGE "Voltage"
   #define D_DOMOTICZ_CURRENT "Current"
+  #define D_DOMOTICZ_AIRQUALITY "AirQuality"
 #define D_DOMOTICZ_UPDATE_TIMER "Update timer"
 
 // xdrv_irremote.ino
@@ -473,12 +475,14 @@
 #define D_SENSOR_RELAY    "Relay "    // Suffix "1i"
 #define D_SENSOR_LED      "LED "      // Suffix "1i"
 #define D_SENSOR_PWM      "PWM "      // Suffix "1"
-#define D_SENSOR_COUNTER  "Counter"  // Suffix "1"
+#define D_SENSOR_COUNTER  "Counter"   // Suffix "1"
 #define D_SENSOR_IRRECV   "IRRecv"
 #define D_SENSOR_MHZ_RX   "MHZ Rx"
 #define D_SENSOR_MHZ_TX   "MHZ Tx"
 #define D_SENSOR_PZEM_RX  "PZEM Rx"
 #define D_SENSOR_PZEM_TX  "PZEM Tx"
+#define D_SENSOR_SAIR_RX  "SAir Rx"
+#define D_SENSOR_SAIR_TX  "SAir Tx"
 #define D_SENSOR_SPI_CS   "SPI CS"
 #define D_SENSOR_SPI_DC   "SPI DC"
 #define D_SENSOR_BACKLIGHT "BLight"
diff --git a/sonoff/language/en-GB.h b/sonoff/language/en-GB.h
index 571fff023..497654872 100644
--- a/sonoff/language/en-GB.h
+++ b/sonoff/language/en-GB.h
@@ -1,7 +1,7 @@
 /*
   en-GB.h - localization for English - United Kingdom for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -66,7 +66,7 @@
 #define D_BUTTON "Button"
 #define D_BY "by"                    // Written by me
 #define D_CELSIUS "Celsius"
-#define D_CO2 "CO2"
+#define D_CO2 "Carbon dioxide"
 #define D_CODE "code"                // Button code
 #define D_COLDLIGHT "Cold"
 #define D_COMMAND "Command"
@@ -118,6 +118,7 @@
 #define D_INITIALIZED "Initialized"
 #define D_IP_ADDRESS "IP Address"
 #define D_LIGHT "Light"
+#define D_LIMIT "Limit"
 #define D_LOCAL_TIME "Local"
 #define D_LOW "Low"
 #define D_LWT "LWT"
@@ -386,6 +387,7 @@
   #define D_DOMOTICZ_COUNT "Count"
   #define D_DOMOTICZ_VOLTAGE "Voltage"
   #define D_DOMOTICZ_CURRENT "Current"
+  #define D_DOMOTICZ_AIRQUALITY "AirQuality"
 #define D_DOMOTICZ_UPDATE_TIMER "Update timer"
 
 // xdrv_irremote.ino
@@ -479,6 +481,8 @@
 #define D_SENSOR_MHZ_TX   "MHZ Tx"
 #define D_SENSOR_PZEM_RX  "PZEM Rx"
 #define D_SENSOR_PZEM_TX  "PZEM Tx"
+#define D_SENSOR_SAIR_RX  "SAir Rx"
+#define D_SENSOR_SAIR_TX  "SAir Tx"
 #define D_SENSOR_SPI_CS   "SPI CS"
 #define D_SENSOR_SPI_DC   "SPI DC"
 #define D_SENSOR_BACKLIGHT "BLight"
diff --git a/sonoff/language/nl-NL.h b/sonoff/language/nl-NL.h
index 13b1b49cb..a6f3b020e 100644
--- a/sonoff/language/nl-NL.h
+++ b/sonoff/language/nl-NL.h
@@ -1,7 +1,7 @@
 /*
   nl-NL.h - localization for Dutch - Nederland for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -66,7 +66,7 @@
 #define D_BUTTON "DrukKnop"
 #define D_BY "door"                  // Written by me
 #define D_CELSIUS "Celsius"
-#define D_CO2 "CO2"
+#define D_CO2 "Koolstofdioxide"
 #define D_CODE "code"                // Button code
 #define D_COLDLIGHT "Koud"
 #define D_COMMAND "Opdracht"
@@ -118,6 +118,7 @@
 #define D_INITIALIZED "Geinitialiseerd"
 #define D_IP_ADDRESS "IP Adres"
 #define D_LIGHT "Ligt"
+#define D_LIMIT "Grenswaarde"
 #define D_LOCAL_TIME "Plaatselijk"
 #define D_LOW "Laag"
 #define D_LWT "LWT"
@@ -386,6 +387,7 @@
   #define D_DOMOTICZ_COUNT "Count"
   #define D_DOMOTICZ_VOLTAGE "Spanning"
   #define D_DOMOTICZ_CURRENT "Stroom"
+  #define D_DOMOTICZ_AIRQUALITY "AirQuality"
 #define D_DOMOTICZ_UPDATE_TIMER "Bijwerk timer"
 
 // xdrv_irremote.ino
@@ -474,11 +476,13 @@
 #define D_SENSOR_LED      "Led"     // Suffix "1i"
 #define D_SENSOR_PWM      "PWM"     // Suffix "1"
 #define D_SENSOR_COUNTER  "Teller"  // Suffix "1"
+#define D_SENSOR_IRRECV   "IRrecv"
 #define D_SENSOR_MHZ_RX   "MHZ Rx"
 #define D_SENSOR_MHZ_TX   "MHZ Tx"
 #define D_SENSOR_PZEM_RX  "PZEM Rx"
 #define D_SENSOR_PZEM_TX  "PZEM Tx"
-#define D_SENSOR_IRRECV   "IRrecv"
+#define D_SENSOR_SAIR_RX  "SAir Rx"
+#define D_SENSOR_SAIR_TX  "SAir Tx"
 #define D_SENSOR_SPI_CS   "SPI CS"
 #define D_SENSOR_SPI_DC   "SPI DC"
 #define D_SENSOR_BACKLIGHT "BLight"
diff --git a/sonoff/language/pl-PL.h b/sonoff/language/pl-PL.h
index 4fd42d4fc..51281d0fd 100644
--- a/sonoff/language/pl-PL.h
+++ b/sonoff/language/pl-PL.h
@@ -1,7 +1,7 @@
 /*
   pl-PL.h - localization for Polish without fonetick - Poland for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends (translated by roblad - Robert L.)
+  Copyright (C) 2018  Theo Arends (translated by roblad - Robert L.)
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -66,7 +66,7 @@
 #define D_BUTTON "Przycisk"
 #define D_BY "by"                    // Written by me
 #define D_CELSIUS "Celsiusza"
-#define D_CO2 "CO2"
+#define D_CO2 "Dwutlenku węgla"
 #define D_CODE "kod"                 // Button code
 #define D_COLDLIGHT "Zimny"
 #define D_COMMAND "Komenda"
@@ -118,6 +118,7 @@
 #define D_INITIALIZED "Zainicjowany"
 #define D_IP_ADDRESS "Adres IP"
 #define D_LIGHT "Swiatlo"
+#define D_LIMIT "Wartość graniczna"
 #define D_LOCAL_TIME "Lokalny"
 #define D_LOW "Niski"
 #define D_LWT "LWT"
@@ -386,6 +387,7 @@
   #define D_DOMOTICZ_COUNT "Licznik"
   #define D_DOMOTICZ_VOLTAGE "Napiecie"
   #define D_DOMOTICZ_CURRENT "Prad"
+  #define D_DOMOTICZ_AIRQUALITY "AirQuality"
 #define D_DOMOTICZ_UPDATE_TIMER "Zaktualizuj czasomierz"
 
 // xdrv_irremote.ino
@@ -479,6 +481,8 @@
 #define D_SENSOR_MHZ_TX   "MHZ Tx"
 #define D_SENSOR_PZEM_RX  "PZEM Rx"
 #define D_SENSOR_PZEM_TX  "PZEM Tx"
+#define D_SENSOR_SAIR_RX  "SAir Rx"
+#define D_SENSOR_SAIR_TX  "SAir Tx"
 #define D_SENSOR_SPI_CS   "SPI CS"
 #define D_SENSOR_SPI_DC   "SPI DC"
 #define D_SENSOR_BACKLIGHT "BLight"
diff --git a/sonoff/settings.h b/sonoff/settings.h
index 049d6a000..b718bf005 100644
--- a/sonoff/settings.h
+++ b/sonoff/settings.h
@@ -1,7 +1,7 @@
 /*
   settings.h - setting variables for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -201,8 +201,8 @@ struct SYSCFG {
   byte          free_451[2];               // 451
 
   uint8_t       sleep;                     // 453
-  uint16_t      domoticz_switch_idx[MAX_DOMOTICZ_IDX]; // 454
-  uint16_t      domoticz_sensor_idx[12];   // 45C
+  uint16_t      domoticz_switch_idx[MAX_DOMOTICZ_IDX];      // 454
+  uint16_t      domoticz_sensor_idx[MAX_DOMOTICZ_SNS_IDX];  // 45C
   uint8_t       module;                    // 474
 
   uint8_t       ws_color[4][3];            // 475
diff --git a/sonoff/settings.ino b/sonoff/settings.ino
index a177e86e4..53eb67eff 100644
--- a/sonoff/settings.ino
+++ b/sonoff/settings.ino
@@ -1,7 +1,7 @@
 /*
   settings.ino - user settings for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/sonoff.h b/sonoff/sonoff.h
index 92725a58b..f18c5820c 100644
--- a/sonoff/sonoff.h
+++ b/sonoff/sonoff.h
@@ -1,7 +1,7 @@
 /*
   sonoff.h - Master header file for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -46,6 +46,7 @@ typedef unsigned long power_t;              // Power (Relay) type
 #define MAX_PULSETIMERS        8            // Max number of supported pulse timers
 #define MAX_FRIENDLYNAMES      4            // Max number of Friendly names
 #define MAX_DOMOTICZ_IDX       4            // Max number of Domoticz device, key and switch indices
+#define MAX_DOMOTICZ_SNS_IDX   12           // Max number of Domoticz sensors indices
 
 #define MODULE                 SONOFF_BASIC // [Module] Select default model
 
diff --git a/sonoff/sonoff.ino b/sonoff/sonoff.ino
index 6ddf00e05..005dff5fa 100644
--- a/sonoff/sonoff.ino
+++ b/sonoff/sonoff.ino
@@ -1,7 +1,7 @@
 /*
   sonoff.ino - Sonoff-Tasmota firmware for iTead Sonoff, Wemos and NodeMCU hardware
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/sonoff_post.h b/sonoff/sonoff_post.h
index 7a16e17d0..56e696573 100644
--- a/sonoff/sonoff_post.h
+++ b/sonoff/sonoff_post.h
@@ -1,7 +1,7 @@
 /*
   sonoff_post.h - Post header file for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/sonoff_template.h b/sonoff/sonoff_template.h
index cbe0037a7..14893593e 100644
--- a/sonoff/sonoff_template.h
+++ b/sonoff/sonoff_template.h
@@ -1,7 +1,7 @@
 /*
   sonoff_template.h - template settings for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -82,6 +82,8 @@ enum UserSelectablePins {
   GPIO_MHZ_RXD,        // MH-Z19 Serial interface
   GPIO_PZEM_TX,        // PZEM004T Serial interface
   GPIO_PZEM_RX,        // PZEM004T Serial interface
+  GPIO_SAIR_TX,        // SenseAir Serial interface
+  GPIO_SAIR_RX,        // SenseAir Serial interface
   GPIO_SENSOR_END };
 
 // Text in webpage Module Parameters and commands GPIOS and GPIO
@@ -145,7 +147,9 @@ const char kSensors[GPIO_SENSOR_END][9] PROGMEM = {
   D_SENSOR_MHZ_TX,
   D_SENSOR_MHZ_RX,
   D_SENSOR_PZEM_TX,
-  D_SENSOR_PZEM_RX
+  D_SENSOR_PZEM_RX,
+  D_SENSOR_SAIR_TX,
+  D_SENSOR_SAIR_RX
 };
 
 // Programmer selectable GPIO functionality offset by user selectable GPIOs
diff --git a/sonoff/support.ino b/sonoff/support.ino
index 9ae7af452..35ff9966b 100644
--- a/sonoff/support.ino
+++ b/sonoff/support.ino
@@ -1,7 +1,7 @@
 /*
   support.ino - support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/user_config.h b/sonoff/user_config.h
index ebc248699..6bd035ec3 100644
--- a/sonoff/user_config.h
+++ b/sonoff/user_config.h
@@ -1,7 +1,7 @@
 /*
   user_config.h - user specific configuration for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -192,7 +192,8 @@
   #define USE_WS2812_CTYPE     1                 // WS2812 Color type (0 - RGB, 1 - GRB, 2 - RGBW, 3 - GRBW)
 //  #define USE_WS2812_DMA                         // DMA supports only GPIO03 (= Serial RXD) (+1k mem). When USE_WS2812_DMA is enabled expect Exceptions on Pow
 
-//#define USE_MHZ19                               // Add support for MH-Z19 CO2 sensor (+1k8 code)
+//#define USE_MHZ19                                // Add support for MH-Z19 CO2 sensor (+1k8 code)
+//#define USE_SENSEAIR                             // Add support for SenseAir K30, K70 and S8 CO2 sensor (+1k8 code)
 
 #define USE_ARILUX_RF                            // Add support for Arilux RF remote controller (+0k8 code)
 
diff --git a/sonoff/user_config_override.h b/sonoff/user_config_override.h
index 37fe10e6c..1008faf72 100644
--- a/sonoff/user_config_override.h
+++ b/sonoff/user_config_override.h
@@ -1,7 +1,7 @@
 /*
   user_config_override.h - user configuration overrides user_config.h for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/webserver.ino b/sonoff/webserver.ino
index 54fb26f19..a71d332f6 100644
--- a/sonoff/webserver.ino
+++ b/sonoff/webserver.ino
@@ -1,7 +1,7 @@
 /*
   webserver.ino - webserver for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xdrv_domoticz.ino b/sonoff/xdrv_domoticz.ino
index 1a0a1c0ac..f1e478d1f 100644
--- a/sonoff/xdrv_domoticz.ino
+++ b/sonoff/xdrv_domoticz.ino
@@ -1,7 +1,7 @@
 /*
   xdrv_domoticz.ino - domoticz support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -40,10 +40,14 @@ enum DomoticzCommands {
 const char kDomoticzCommands[] PROGMEM =
   D_CMND_IDX "|" D_CMND_KEYIDX "|" D_CMND_SWITCHIDX "|" D_CMND_SENSORIDX "|" D_CMND_UPDATETIMER ;
 
-enum DomoticzSensors {DZ_TEMP, DZ_TEMP_HUM, DZ_TEMP_HUM_BARO, DZ_POWER_ENERGY, DZ_ILLUMINANCE, DZ_COUNT, DZ_VOLTAGE, DZ_CURRENT, DZ_MAX_SENSORS};
+enum DomoticzSensors {DZ_TEMP, DZ_TEMP_HUM, DZ_TEMP_HUM_BARO, DZ_POWER_ENERGY, DZ_ILLUMINANCE, DZ_COUNT, DZ_VOLTAGE, DZ_CURRENT, DZ_AIRQUALITY, DZ_MAX_SENSORS};
+
+#if MAX_DOMOTICZ_SNS_IDX < DZ_MAX_SENSORS
+  #error "Domoticz: Too many sensors or change settings.h layout"
+#endif
 
 const char kDomoticzSensors[] PROGMEM =
-  D_DOMOTICZ_TEMP "|" D_DOMOTICZ_TEMP_HUM "|" D_DOMOTICZ_TEMP_HUM_BARO "|" D_DOMOTICZ_POWER_ENERGY "|" D_DOMOTICZ_ILLUMINANCE "|" D_DOMOTICZ_COUNT "|" D_DOMOTICZ_VOLTAGE "|" D_DOMOTICZ_CURRENT ;
+  D_DOMOTICZ_TEMP "|" D_DOMOTICZ_TEMP_HUM "|" D_DOMOTICZ_TEMP_HUM_BARO "|" D_DOMOTICZ_POWER_ENERGY "|" D_DOMOTICZ_ILLUMINANCE "|" D_DOMOTICZ_COUNT "|" D_DOMOTICZ_VOLTAGE "|" D_DOMOTICZ_CURRENT "|" D_DOMOTICZ_AIRQUALITY ;
 
 const char S_JSON_DOMOTICZ_COMMAND_INDEX_NVALUE[] PROGMEM = "{\"" D_CMND_DOMOTICZ "%s%d\":%d}";
 
@@ -254,6 +258,19 @@ boolean DomoticzButton(byte key, byte device, byte state, byte svalflg)
 
 /*********************************************************************************************\
  * Sensors
+ *
+ * Source : https://www.domoticz.com/wiki/Domoticz_API/JSON_URL%27s
+ *          https://www.domoticz.com/wiki/MQTT
+ *
+ * Percentage, Barometric, Air Quality:
+ * {\"idx\":%d,\"nvalue\":%s}, Idx, Value
+ *
+ * Humidity:
+ * {\"idx\":%d,\"nvalue\":%s,\"svalue\":\"%s\"}, Idx, Humidity, HumidityStatus
+ *
+ * All other:
+ * {\"idx\":%d,\"nvalue\":0,\"svalue\":\"%s\"}, Idx, Value(s)
+ *
 \*********************************************************************************************/
 
 uint8_t DomoticzHumidityState(char *hum)
@@ -268,8 +285,11 @@ void DomoticzSensor(byte idx, char *data)
     char dmess[64];
 
     memcpy(dmess, mqtt_data, sizeof(dmess));
-    snprintf_P(mqtt_data, sizeof(dmess), PSTR("{\"idx\":%d,\"nvalue\":0,\"svalue\":\"%s\"}"),
-      Settings.domoticz_sensor_idx[idx], data);
+    if (DZ_AIRQUALITY == idx) {
+      snprintf_P(mqtt_data, sizeof(dmess), PSTR("{\"idx\":%d,\"nvalue\":%s}"), Settings.domoticz_sensor_idx[idx], data);
+    } else {
+      snprintf_P(mqtt_data, sizeof(dmess), PSTR("{\"idx\":%d,\"nvalue\":0,\"svalue\":\"%s\"}"), Settings.domoticz_sensor_idx[idx], data);
+    }
     MqttPublish(domoticz_in_topic);
     memcpy(mqtt_data, dmess, sizeof(dmess));
   }
@@ -353,6 +373,7 @@ void HandleDomoticzConfiguration()
 void DomoticzSaveSettings()
 {
   char stemp[20];
+  char ssensor_indices[6 * MAX_DOMOTICZ_SNS_IDX];
 
   for (byte i = 0; i < MAX_DOMOTICZ_IDX; i++) {
     snprintf_P(stemp, sizeof(stemp), PSTR("r%d"), i +1);
@@ -362,20 +383,19 @@ void DomoticzSaveSettings()
     snprintf_P(stemp, sizeof(stemp), PSTR("s%d"), i +1);
     Settings.domoticz_switch_idx[i] = (!strlen(WebServer->arg(stemp).c_str())) ? 0 : atoi(WebServer->arg(stemp).c_str());
   }
+  ssensor_indices[0] = '\0';
   for (byte i = 0; i < DZ_MAX_SENSORS; i++) {
     snprintf_P(stemp, sizeof(stemp), PSTR("l%d"), i +1);
     Settings.domoticz_sensor_idx[i] = (!strlen(WebServer->arg(stemp).c_str())) ? 0 : atoi(WebServer->arg(stemp).c_str());
+    snprintf_P(ssensor_indices, sizeof(ssensor_indices), PSTR("%s%s%d"), ssensor_indices, (strlen(ssensor_indices)) ? "," : "",  Settings.domoticz_sensor_idx[i]);
   }
   Settings.domoticz_update_timer = (!strlen(WebServer->arg("ut").c_str())) ? DOMOTICZ_UPDATE_TIMER : atoi(WebServer->arg("ut").c_str());
-  snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_DOMOTICZ D_CMND_IDX " %d, %d, %d, %d, " D_CMND_UPDATETIMER " %d"),
+
+  snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_DOMOTICZ D_CMND_IDX " %d,%d,%d,%d, " D_CMND_KEYIDX " %d,%d,%d,%d, " D_CMND_SWITCHIDX " %d,%d,%d,%d, " D_CMND_SENSORIDX " %s, " D_CMND_UPDATETIMER " %d"),
     Settings.domoticz_relay_idx[0], Settings.domoticz_relay_idx[1], Settings.domoticz_relay_idx[2], Settings.domoticz_relay_idx[3],
-    Settings.domoticz_update_timer);
-  AddLog(LOG_LEVEL_INFO);
-  snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_DOMOTICZ D_CMND_KEYIDX " %d, %d, %d, %d, " D_CMND_SWITCHIDX " %d, %d, %d, %d, " D_CMND_SENSORIDX " %d, %d, %d, %d, %d, %d, %d, %d"),
     Settings.domoticz_key_idx[0], Settings.domoticz_key_idx[1], Settings.domoticz_key_idx[2], Settings.domoticz_key_idx[3],
     Settings.domoticz_switch_idx[0], Settings.domoticz_switch_idx[1], Settings.domoticz_switch_idx[2], Settings.domoticz_switch_idx[3],
-    Settings.domoticz_sensor_idx[0], Settings.domoticz_sensor_idx[1], Settings.domoticz_sensor_idx[2], Settings.domoticz_sensor_idx[3],
-    Settings.domoticz_sensor_idx[4], Settings.domoticz_sensor_idx[5], Settings.domoticz_sensor_idx[6], Settings.domoticz_sensor_idx[7]);
+    ssensor_indices, Settings.domoticz_update_timer);
   AddLog(LOG_LEVEL_INFO);
 }
 #endif  // USE_WEBSERVER
diff --git a/sonoff/xdrv_irremote.ino b/sonoff/xdrv_irremote.ino
index 423270684..8a54adf8b 100644
--- a/sonoff/xdrv_irremote.ino
+++ b/sonoff/xdrv_irremote.ino
@@ -1,7 +1,7 @@
 /*
   xdrv_irremote.ino - infra red support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Heiko Krupp, Lazar Obradovic and Theo Arends
+  Copyright (C) 2018  Heiko Krupp, Lazar Obradovic and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xdrv_light.ino b/sonoff/xdrv_light.ino
index 2eff11895..3b82f74cf 100644
--- a/sonoff/xdrv_light.ino
+++ b/sonoff/xdrv_light.ino
@@ -1,7 +1,7 @@
 /*
   xdrv_light.ino - PWM, WS2812 and sonoff led support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xdrv_snfbridge.ino b/sonoff/xdrv_snfbridge.ino
index d475860dd..6c7993cd4 100644
--- a/sonoff/xdrv_snfbridge.ino
+++ b/sonoff/xdrv_snfbridge.ino
@@ -1,7 +1,7 @@
 /*
   xdrv_snfbridge.ino - sonoff RF bridge 433 support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xdrv_wemohue.ino b/sonoff/xdrv_wemohue.ino
index 05d4ed7ef..14d86b05a 100755
--- a/sonoff/xdrv_wemohue.ino
+++ b/sonoff/xdrv_wemohue.ino
@@ -1,7 +1,7 @@
 /*
   xdrv_wemohue.ino - wemo and hue support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Heiko Krupp and Theo Arends
+  Copyright (C) 2018  Heiko Krupp and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xdrv_ws2812.ino b/sonoff/xdrv_ws2812.ino
index 8add8c513..2aea22054 100644
--- a/sonoff/xdrv_ws2812.ino
+++ b/sonoff/xdrv_ws2812.ino
@@ -1,7 +1,7 @@
 /*
   xdrv_ws2812.ino - ws2812 led string support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Heiko Krupp and Theo Arends
+  Copyright (C) 2018  Heiko Krupp and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_01_counter.ino b/sonoff/xsns_01_counter.ino
index 7b3f72d9f..743822af6 100644
--- a/sonoff/xsns_01_counter.ino
+++ b/sonoff/xsns_01_counter.ino
@@ -1,7 +1,7 @@
 /*
   xsns_01_counter.ino - Counter sensors (water meters, electricity meters etc.) sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Maarten Damen and Theo Arends
+  Copyright (C) 2018  Maarten Damen and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_03_energy.ino b/sonoff/xsns_03_energy.ino
index c23664873..cc02fef11 100644
--- a/sonoff/xsns_03_energy.ino
+++ b/sonoff/xsns_03_energy.ino
@@ -1,7 +1,7 @@
 /*
   xsns_03_energy.ino - HLW8012 (Sonoff Pow) and PZEM004T energy sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_04_snfsc.ino b/sonoff/xsns_04_snfsc.ino
index 98ff02c0f..04a552ac5 100644
--- a/sonoff/xsns_04_snfsc.ino
+++ b/sonoff/xsns_04_snfsc.ino
@@ -1,7 +1,7 @@
 /*
   xsns_04_snfsc.ino - sonoff SC support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_05_ds18b20.ino b/sonoff/xsns_05_ds18b20.ino
index 343b42fea..19281349e 100644
--- a/sonoff/xsns_05_ds18b20.ino
+++ b/sonoff/xsns_05_ds18b20.ino
@@ -1,7 +1,7 @@
 /*
   xsns_05_ds18b20.ino - DS18B20 temperature sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_05_ds18x20.ino b/sonoff/xsns_05_ds18x20.ino
index 0e7553940..c0bd66673 100644
--- a/sonoff/xsns_05_ds18x20.ino
+++ b/sonoff/xsns_05_ds18x20.ino
@@ -1,7 +1,7 @@
 /*
   xsns_05_ds18x20.ino - DS18x20 temperature sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_05_ds18x20_legacy.ino b/sonoff/xsns_05_ds18x20_legacy.ino
index 5d6553f6d..0a389300c 100644
--- a/sonoff/xsns_05_ds18x20_legacy.ino
+++ b/sonoff/xsns_05_ds18x20_legacy.ino
@@ -1,7 +1,7 @@
 /*
   xsns_05_ds18x20_legacy.ino - DS18x20 temperature sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Heiko Krupp and Theo Arends
+  Copyright (C) 2018  Heiko Krupp and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_06_dht.ino b/sonoff/xsns_06_dht.ino
index 64d8baf78..3598c40f2 100644
--- a/sonoff/xsns_06_dht.ino
+++ b/sonoff/xsns_06_dht.ino
@@ -1,7 +1,7 @@
 /*
   xsns_06_dht.ino - DHTxx, AM23xx and SI7021 temperature and humidity sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_07_sht1x.ino b/sonoff/xsns_07_sht1x.ino
index 9b74d31a0..dad419f5e 100644
--- a/sonoff/xsns_07_sht1x.ino
+++ b/sonoff/xsns_07_sht1x.ino
@@ -1,7 +1,7 @@
 /*
   xsns_07_sht1x.ino - SHT1x temperature and sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_08_htu21.ino b/sonoff/xsns_08_htu21.ino
index 7bafad1d9..4950be405 100644
--- a/sonoff/xsns_08_htu21.ino
+++ b/sonoff/xsns_08_htu21.ino
@@ -1,7 +1,7 @@
 /*
   xsns_08_htu21.ino - HTU21 temperature and humidity sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Heiko Krupp and Theo Arends
+  Copyright (C) 2018  Heiko Krupp and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_09_bmp.ino b/sonoff/xsns_09_bmp.ino
index 74e310ef1..f3130abde 100644
--- a/sonoff/xsns_09_bmp.ino
+++ b/sonoff/xsns_09_bmp.ino
@@ -1,7 +1,7 @@
 /*
   xsns_09_bmp.ino - BMP pressure, temperature, humidity and gas sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Heiko Krupp and Theo Arends
+  Copyright (C) 2018  Heiko Krupp and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_10_bh1750.ino b/sonoff/xsns_10_bh1750.ino
index f8be2cfbb..1a8873647 100644
--- a/sonoff/xsns_10_bh1750.ino
+++ b/sonoff/xsns_10_bh1750.ino
@@ -1,7 +1,7 @@
 /*
   xsns_10_bh1750.ino - BH1750 ambient light sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_11_veml6070.ino b/sonoff/xsns_11_veml6070.ino
index cc62771c1..aafd0da74 100644
--- a/sonoff/xsns_11_veml6070.ino
+++ b/sonoff/xsns_11_veml6070.ino
@@ -1,7 +1,7 @@
 /*
   xsns_11_veml6070.ino - VEML6070 ultra violet light sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_12_ads1115.ino b/sonoff/xsns_12_ads1115.ino
index 675b15101..447ad98c9 100644
--- a/sonoff/xsns_12_ads1115.ino
+++ b/sonoff/xsns_12_ads1115.ino
@@ -1,7 +1,7 @@
 /*
   xsns_12_ads1115_ada.ino - ADS1115 A/D Converter support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_12_ads1115_i2cdev.ino b/sonoff/xsns_12_ads1115_i2cdev.ino
index 8856da70f..0d599f0a5 100644
--- a/sonoff/xsns_12_ads1115_i2cdev.ino
+++ b/sonoff/xsns_12_ads1115_i2cdev.ino
@@ -1,7 +1,7 @@
 /*
   xsns_12_ads1115.ino - ADS1x15 A/D Converter support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Stefan Bode and Theo Arends
+  Copyright (C) 2018  Stefan Bode and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_13_ina219.ino b/sonoff/xsns_13_ina219.ino
index 485c91452..4848b383b 100644
--- a/sonoff/xsns_13_ina219.ino
+++ b/sonoff/xsns_13_ina219.ino
@@ -1,7 +1,7 @@
 /*
   xsns_13_ina219.ino - INA219 Current Sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Stefan Bode and Theo Arends
+  Copyright (C) 2018  Stefan Bode and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_14_sht3x.ino b/sonoff/xsns_14_sht3x.ino
index f58fc3999..35800adf2 100644
--- a/sonoff/xsns_14_sht3x.ino
+++ b/sonoff/xsns_14_sht3x.ino
@@ -1,7 +1,7 @@
 /*
   xsns_14_sht3x.ino - SHT3X temperature and humidity sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_14_sht3x_v2.ino b/sonoff/xsns_14_sht3x_v2.ino
index 0ed9d0bd8..f794d971b 100644
--- a/sonoff/xsns_14_sht3x_v2.ino
+++ b/sonoff/xsns_14_sht3x_v2.ino
@@ -1,7 +1,7 @@
 /*
   xsns_14_sht3x.ino - SHT3X temperature and humidity sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_14_sht3x_v3.ino b/sonoff/xsns_14_sht3x_v3.ino
index a078fff91..e165fbf01 100644
--- a/sonoff/xsns_14_sht3x_v3.ino
+++ b/sonoff/xsns_14_sht3x_v3.ino
@@ -1,7 +1,7 @@
 /*
   xsns_14_sht3x.ino - SHT3X temperature and humidity sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_15_mhz19.ino b/sonoff/xsns_15_mhz19.ino
index 9789d0f81..4b5b24ec3 100644
--- a/sonoff/xsns_15_mhz19.ino
+++ b/sonoff/xsns_15_mhz19.ino
@@ -1,5 +1,5 @@
 /*
-  xsns_15_mhz.ino - MH-Z19(B) CO2 sensor support for Sonoff-Tasmota
+  xsns_15_mhz19.ino - MH-Z19(B) CO2 sensor support for Sonoff-Tasmota
 
   Copyright (C) 2018  Theo Arends
 
@@ -227,7 +227,7 @@ bool Mhz19CheckAndApplyFilter(uint16_t ppm, uint8_t s)
   return true;
 }
 
-void Mhz19222ms()
+void Mhz19Ticker()
 {
   uint8_t mhz19_response[9];
 
@@ -314,26 +314,24 @@ void Mhz19Init()
   if ((pin[GPIO_MHZ_RXD] < 99) && (pin[GPIO_MHZ_TXD] < 99)) {
     if (Mhz19Serial(pin[GPIO_MHZ_RXD], pin[GPIO_MHZ_TXD])) {
       mhz19_type = 1;
-      mhz19_ticker.attach_ms(222, Mhz19222ms);
+      mhz19_ticker.attach_ms(222, Mhz19Ticker);
     }
   }
 }
 
-#ifdef USE_WEBSERVER
-const char HTTP_SNS_CO2[] PROGMEM =
-  "%s{s}%s " D_CO2 "{m}%d " D_UNIT_PPM "{e}";  // {s} = <tr><th>, {m} = </th><td>, {e} = </td></tr>
-#endif  // USE_WEBSERVER
-
 void Mhz19Show(boolean json)
 {
   char temperature[10];
   dtostrfd(mhz19_temperature, Settings.flag2.temperature_resolution, temperature);
   GetTextIndexed(mhz19_types, sizeof(mhz19_types), mhz19_type -1, kMhz19Types);
+//  uint8_t co2_limit = (mhz19_last_ppm > 1200) ? 3 : (mhz19_last_ppm > 800) ? 2 : 1;
+//  uint16_t co2_limit = mhz19_last_ppm / 400;  // <800 = 1(Green), <1200 = 2(Orange), >1200 = 3(Red)
 
   if (json) {
+//    snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s,\"%s\":{\"" D_CO2 "\":%d,\"" D_LIMIT "\":%d,\"" D_TEMPERATURE "\":%s}"), mqtt_data, mhz19_types, mhz19_last_ppm, co2_limit, temperature);
     snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s,\"%s\":{\"" D_CO2 "\":%d,\"" D_TEMPERATURE "\":%s}"), mqtt_data, mhz19_types, mhz19_last_ppm, temperature);
 #ifdef USE_DOMOTICZ
-    DomoticzSensor(DZ_COUNT, mhz19_last_ppm);
+    DomoticzSensor(DZ_AIRQUALITY, mhz19_last_ppm);
 #endif  // USE_DOMOTICZ
 #ifdef USE_WEBSERVER
   } else {
diff --git a/sonoff/xsns_16_tsl2561.ino b/sonoff/xsns_16_tsl2561.ino
index 2769b9a1d..12c0b15c2 100644
--- a/sonoff/xsns_16_tsl2561.ino
+++ b/sonoff/xsns_16_tsl2561.ino
@@ -1,7 +1,7 @@
 /*
   xsns_16_tsl2561.ino - TSL2561 light sensor support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends
+  Copyright (C) 2018  Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
diff --git a/sonoff/xsns_17_senseair.ino b/sonoff/xsns_17_senseair.ino
new file mode 100644
index 000000000..56ab7595f
--- /dev/null
+++ b/sonoff/xsns_17_senseair.ino
@@ -0,0 +1,361 @@
+/*
+  xsns_17_senseair_s8.ino - SenseAir S8 CO2 sensor support for Sonoff-Tasmota
+
+  Copyright (C) 2018  Theo Arends
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifdef USE_SENSEAIR
+/*********************************************************************************************\
+ * SenseAir S8 - CO2 sensor
+ *
+ * Adapted from EspEasy plugin P052 by Mikael Trieb (mikael__AT__triebconsulting.se)
+ **********************************************************************************************
+ * Filter usage
+ *
+ * Select filter usage on low stability readings
+\*********************************************************************************************/
+
+#define SENSEAIR_BAUDRATE               9600
+
+const char kSenseairTypes[] PROGMEM = "Kx0|S8";
+
+uint8_t senseair_type = 1;
+char senseair_types[7];
+
+uint16_t senseair_co2 = 0;
+float senseair_temperature = 0;
+float senseair_humidity = 0;
+
+Ticker senseair_ticker;
+
+/*********************************************************************************************\
+ * Subset SoftwareSerial
+\*********************************************************************************************/
+
+#define SENSEAIR_SERIAL_BUFFER_SIZE     20
+#define SENSEAIR_SERIAL_WAIT { while (ESP.getCycleCount() -start < wait) optimistic_yield(1); wait += senseair_serial_bit_time; }
+
+uint8_t senseair_serial_rx_pin;
+uint8_t senseair_serial_tx_pin;
+uint8_t senseair_serial_in_pos = 0;
+uint8_t senseair_serial_out_pos = 0;
+uint8_t senseair_serial_buffer[SENSEAIR_SERIAL_BUFFER_SIZE];
+unsigned long senseair_serial_bit_time;
+unsigned long senseair_serial_bit_time_start;
+
+bool SenseairSerialValidGpioPin(uint8_t pin) {
+  return (pin >= 0 && pin <= 5) || (pin >= 9 && pin <= 10) || (pin >= 12 && pin <= 15);
+}
+
+bool SenseairSerial(uint8_t receive_pin, uint8_t transmit_pin)
+{
+  if (!((SenseairSerialValidGpioPin(receive_pin)) && (SenseairSerialValidGpioPin(transmit_pin) || transmit_pin == 16))) {
+    return false;
+  }
+  senseair_serial_rx_pin = receive_pin;
+  pinMode(senseair_serial_rx_pin, INPUT);
+  attachInterrupt(senseair_serial_rx_pin, SenseairSerialRxRead, FALLING);
+
+  senseair_serial_tx_pin = transmit_pin;
+  pinMode(senseair_serial_tx_pin, OUTPUT);
+  digitalWrite(senseair_serial_tx_pin, 1);
+
+  senseair_serial_bit_time = ESP.getCpuFreqMHz() *1000000 /SENSEAIR_BAUDRATE;   // 8333
+  senseair_serial_bit_time_start = senseair_serial_bit_time + senseair_serial_bit_time /3 -500;  // 10610 ICACHE_RAM_ATTR start delay
+//  senseair_serial_bit_time_start = senseair_serial_bit_time;                           // Non ICACHE_RAM_ATTR start delay (experimental)
+
+  return true;
+}
+
+int SenseairSerialRead() {
+  if (senseair_serial_in_pos == senseair_serial_out_pos) {
+    return -1;
+  }
+  int ch = senseair_serial_buffer[senseair_serial_out_pos];
+  senseair_serial_out_pos = (senseair_serial_out_pos +1) % SENSEAIR_SERIAL_BUFFER_SIZE;
+  return ch;
+}
+
+int SenseairSerialAvailable() {
+  int avail = senseair_serial_in_pos - senseair_serial_out_pos;
+  if (avail < 0) {
+    avail += SENSEAIR_SERIAL_BUFFER_SIZE;
+  }
+  return avail;
+}
+
+void SenseairSerialFlush()
+{
+  senseair_serial_in_pos = 0;
+  senseair_serial_out_pos = 0;
+}
+
+size_t SenseairSerialTxWrite(uint8_t b)
+{
+  unsigned long wait = senseair_serial_bit_time;
+  digitalWrite(senseair_serial_tx_pin, HIGH);
+  unsigned long start = ESP.getCycleCount();
+    // Start bit;
+  digitalWrite(senseair_serial_tx_pin, LOW);
+  SENSEAIR_SERIAL_WAIT;
+  for (int i = 0; i < 8; i++) {
+    digitalWrite(senseair_serial_tx_pin, (b & 1) ? HIGH : LOW);
+    SENSEAIR_SERIAL_WAIT;
+    b >>= 1;
+  }
+   // Stop bit
+  digitalWrite(senseair_serial_tx_pin, HIGH);
+  SENSEAIR_SERIAL_WAIT;
+  return 1;
+}
+
+size_t SenseairSerialWrite(const uint8_t *buffer, size_t size = 1) {
+  size_t n = 0;
+  while(size--) {
+    n += SenseairSerialTxWrite(*buffer++);
+  }
+  return n;
+}
+
+//void SenseairSerialRxRead() ICACHE_RAM_ATTR;  // Add 215 bytes to iram usage
+void SenseairSerialRxRead() {
+  // Advance the starting point for the samples but compensate for the
+  // initial delay which occurs before the interrupt is delivered
+  unsigned long wait = senseair_serial_bit_time_start;
+  unsigned long start = ESP.getCycleCount();
+  uint8_t rec = 0;
+  for (int i = 0; i < 8; i++) {
+    SENSEAIR_SERIAL_WAIT;
+    rec >>= 1;
+    if (digitalRead(senseair_serial_rx_pin)) {
+      rec |= 0x80;
+    }
+  }
+  // Stop bit
+  SENSEAIR_SERIAL_WAIT;
+  // Store the received value in the buffer unless we have an overflow
+  int next = (senseair_serial_in_pos +1) % SENSEAIR_SERIAL_BUFFER_SIZE;
+  if (next != senseair_serial_out_pos) {
+    senseair_serial_buffer[senseair_serial_in_pos] = rec;
+    senseair_serial_in_pos = next;
+  }
+  // Must clear this bit in the interrupt register,
+  // it gets set even when interrupts are disabled
+  GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, 1 << senseair_serial_rx_pin);
+}
+
+/*********************************************************************************************/
+
+void ModbusSend(uint8_t function_code, uint16_t start_address, uint16_t register_count)
+{
+  uint8_t frame[8];
+
+  frame[0] = 0xFE;  // Any Address
+  frame[1] = function_code;
+  frame[2] = (uint8_t)(start_address >> 8);
+  frame[3] = (uint8_t)(start_address);
+  frame[4] = (uint8_t)(register_count >> 8);
+  frame[5] = (uint8_t)(register_count);
+  uint16_t crc = 0xFFFF;
+  for (uint8_t pos = 0; pos < sizeof(frame) -2; pos++) {
+    crc ^= (uint16_t)frame[pos];        // XOR byte into least sig. byte of crc
+    for (uint8_t i = 8; i != 0; i--) {  // Loop over each bit
+      if ((crc & 0x0001) != 0) {        // If the LSB is set
+        crc >>= 1;                      // Shift right and XOR 0xA001
+        crc ^= 0xA001;
+      }
+      else {                            // Else LSB is not set
+        crc >>= 1;                      // Just shift right
+      }
+    }
+  }
+  frame[7] = (uint8_t)((crc >> 8) & 0xFF);
+  frame[6] = (uint8_t)(crc & 0xFF);
+
+  SenseairSerialFlush();
+  SenseairSerialWrite(frame, sizeof(frame));
+}
+
+bool ModbusReceiveReady()
+{
+  return (SenseairSerialAvailable() >= 5);  // 5 - Error frame, 7 - Ok frame
+}
+
+uint8_t ModbusReceive(uint16_t *value)
+{
+  uint8_t buffer[7];
+
+  uint8_t len = 0;
+  while (SenseairSerialAvailable() > 0) {
+    buffer[len++] = (uint8_t)SenseairSerialRead();
+    if (3 == len) {
+      if (buffer[1] & 0x80) {  // fe 84 02 f2 f1
+        return buffer[2];      // 1 = Illegal Function, 2 = Illegal Data Address, 3 = Illegal Data Value
+      }
+    }
+  }
+  if (len != sizeof(buffer)) {
+    return 9;                  // 9 = Unexpected result
+  }
+  *value = (buffer[3] << 8) | buffer[4];
+  return 0;                    // 0 = No error
+}
+
+/*********************************************************************************************/
+
+const uint8_t start_addresses[] { 0x1A, 0x00, 0x03, 0x04, 0x05, 0x1C, 0x0A };
+
+uint8_t senseair_read_state = 0;
+uint8_t senseair_send_retry = 0;
+
+void SenseairTicker()
+{
+  uint16_t value = 0;
+  bool data_ready = ModbusReceiveReady();
+
+  if (data_ready) {
+    uint8_t error = ModbusReceive(&value);
+    if (error) {
+      snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_DEBUG "SenseAir response error %d"), error);
+      AddLog(LOG_LEVEL_DEBUG);
+    } else {
+      switch(senseair_read_state) {
+        case 0:                          // 0x1A (26) READ_TYPE_LOW - S8: fe 04 02 01 77 ec 92
+          senseair_type = 2;
+          snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_DEBUG "SenseAir type id low %04X"), value);
+          AddLog(LOG_LEVEL_DEBUG);
+          break;
+        case 1:                          // 0x00 (0) READ_ERRORLOG - fe 04 02 00 00 ad 24
+          if (value) {
+            snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_DEBUG "SenseAir error %04X"), value);
+            AddLog(LOG_LEVEL_DEBUG);
+          }
+          break;
+        case 2:                          // 0x03 (3) READ_CO2 - fe 04 02 06 2c af 59
+          senseair_co2 = value;
+          break;
+        case 3:                          // 0x04 (4) READ_TEMPERATURE - S8: fe 84 02 f2 f1 - Illegal Data Address
+          senseair_temperature = ConvertTemp((float)value / 100);
+          break;
+        case 4:                          // 0x05 (5) READ_HUMIDITY - S8: fe 84 02 f2 f1 - Illegal Data Address
+          senseair_humidity = (float)value / 100;
+          break;
+        case 5:                          // 0x1C (28) READ_RELAY_STATE - S8: fe 04 02 01 54 ad 4b - firmware version
+        {
+          bool relay_state = value >> 8 & 1;
+          snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_DEBUG "SenseAir relay state %d"), relay_state);
+          AddLog(LOG_LEVEL_DEBUG);
+          break;
+        }
+        case 6:                          // 0x0A (10) READ_TEMP_ADJUSTMENT - S8: fe 84 02 f2 f1 - Illegal Data Address
+          snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_DEBUG "SenseAir temp adjustment %d"), value);
+          AddLog(LOG_LEVEL_DEBUG);
+          break;
+      }
+    }
+    senseair_read_state++;
+    if (2 == senseair_type) {  // S8
+      if (3 == senseair_read_state) {
+        senseair_read_state = 1;
+      }
+    } else {                   // K30, K70
+      if (sizeof(start_addresses) == senseair_read_state) {
+        senseair_read_state = 1;
+      }
+    }
+  }
+
+  if (0 == senseair_send_retry || data_ready) {
+    senseair_send_retry = 5;
+    ModbusSend(0x04, (uint16_t)start_addresses[senseair_read_state], 1);
+  } else {
+    senseair_send_retry--;
+  }
+}
+
+/*********************************************************************************************/
+
+void SenseairInit()
+{
+  senseair_type = 0;
+  if ((pin[GPIO_SAIR_RX] < 99) && (pin[GPIO_SAIR_TX] < 99)) {
+    if (SenseairSerial(pin[GPIO_SAIR_RX], pin[GPIO_SAIR_TX])) {
+      senseair_type = 1;
+      senseair_ticker.attach_ms(510, SenseairTicker);
+    }
+  }
+}
+
+void SenseairShow(boolean json)
+{
+  char temperature[10];
+  char humidity[10];
+  dtostrfd(senseair_temperature, Settings.flag2.temperature_resolution, temperature);
+  dtostrfd(senseair_humidity, Settings.flag2.temperature_resolution, humidity);
+  GetTextIndexed(senseair_types, sizeof(senseair_types), senseair_type -1, kSenseairTypes);
+//  uint8_t co2_limit = (senseair_co2 > 1200) ? 3 : (senseair_co2 > 800) ? 2 : 1;
+//  uint16_t co2_limit = senseair_co2 / 400;  // <800 = 1(Green), <1200 = 2(Orange), >1200 = 3(Red)
+
+  if (json) {
+//    snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s,\"%s\":{\"" D_CO2 "\":%d,\"" D_LIMIT "\":%d"), mqtt_data, senseair_types, senseair_co2, co2_limit);
+    snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s,\"%s\":{\"" D_CO2 "\":%d"), mqtt_data, senseair_types, senseair_co2);
+    if (senseair_type != 2) {
+      snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s,\"" D_TEMPERATURE "\":%s,\"" D_HUMIDITY "\":%s"), mqtt_data, temperature, humidity);
+    }
+    snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s}"), mqtt_data);
+#ifdef USE_DOMOTICZ
+    DomoticzSensor(DZ_AIRQUALITY, senseair_co2);
+#endif  // USE_DOMOTICZ
+#ifdef USE_WEBSERVER
+  } else {
+    snprintf_P(mqtt_data, sizeof(mqtt_data), HTTP_SNS_CO2, mqtt_data, senseair_types, senseair_co2);
+    if (senseair_type != 2) {
+      snprintf_P(mqtt_data, sizeof(mqtt_data), HTTP_SNS_TEMP, mqtt_data, senseair_types, temperature, TempUnit());
+      snprintf_P(mqtt_data, sizeof(mqtt_data), HTTP_SNS_HUM, mqtt_data, senseair_types, humidity);
+    }
+#endif  // USE_WEBSERVER
+  }
+}
+
+/*********************************************************************************************\
+ * Interface
+\*********************************************************************************************/
+
+#define XSNS_17
+
+boolean Xsns17(byte function)
+{
+  boolean result = false;
+
+  if (senseair_type) {
+    switch (function) {
+      case FUNC_XSNS_INIT:
+        SenseairInit();
+        break;
+      case FUNC_XSNS_JSON_APPEND:
+        SenseairShow(1);
+        break;
+#ifdef USE_WEBSERVER
+      case FUNC_XSNS_WEB_APPEND:
+        SenseairShow(0);
+        break;
+#endif  // USE_WEBSERVER
+    }
+  }
+  return result;
+}
+
+#endif  // USE_SENSEAIR
diff --git a/sonoff/xsns_interface.ino b/sonoff/xsns_interface.ino
index c7d5c3e2f..d07982037 100644
--- a/sonoff/xsns_interface.ino
+++ b/sonoff/xsns_interface.ino
@@ -1,7 +1,7 @@
 /*
   xsns_interface.ino - External sensor interface support for Sonoff-Tasmota
 
-  Copyright (C) 2017  Theo Arends inspired by ESPEasy
+  Copyright (C) 2018  Theo Arends inspired by ESPEasy
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by