diff --git a/BUILDS.md b/BUILDS.md
index f22f73a66..5aa175e49 100644
--- a/BUILDS.md
+++ b/BUILDS.md
@@ -234,6 +234,7 @@ Note: the `minimal` variant is not listed as it shouldn't be used outside of the
 | USE_HC8                   | -     | - / - | -     | -     | -     | -     |
 | USE_PIPSOLAR              | -     | - / - | -     | -     | -     | -     |
 | USE_WOOLIIS               | -     | - / - | -     | -     | -     | -     |
+| USE_C8_CO2_5K             | -     | - / - | -     | -     | -     | -     |
 |                           |       |       |       |       |       |       |
 | USE_NRF24                 | -     | - / - | -     | -     | -     | -     |
 | USE_MIBLE                 | -     | - / - | -     | -     | -     | -     |
diff --git a/CODE_OWNERS.md b/CODE_OWNERS.md
index f70f2b8ff..908dbb37d 100644
--- a/CODE_OWNERS.md
+++ b/CODE_OWNERS.md
@@ -230,6 +230,7 @@ In addition to @arendst the following code is mainly owned by:
 | xsns_113_hc8                 | Daniel Maier
 | xsns_114_amsx915             | Bastian Urschel
 | xsns_115_wooliis             | Luca Melette
+| xsns_117_c8_co2_5k           | @jeroenvermeulen
 |                              |
 | xsns_127_esp32_sensors       | @arendst
 |                              |
diff --git a/tasmota/berry/include/be_gpio_defines.h b/tasmota/berry/include/be_gpio_defines.h
index 9b9880872..fc868e6d5 100644
--- a/tasmota/berry/include/be_gpio_defines.h
+++ b/tasmota/berry/include/be_gpio_defines.h
@@ -50,6 +50,8 @@ const be_const_member_t lv_gpio_constants[] = {
     { "BS814_DAT", (int32_t) GPIO_BS814_DAT },
     { "BUZZER", (int32_t) GPIO_BUZZER },
     { "BUZZER_INV", (int32_t) GPIO_BUZZER_INV },
+    { "C8_CO2_5K_TX", (int32_t) GPIO_C8_CO2_5K_TX },
+    { "C8_CO2_5K_RX", (int32_t) GPIO_C8_CO2_5K_RX },
     { "CC1101_GDO0", (int32_t) GPIO_CC1101_GDO0 },
     { "CC1101_GDO2", (int32_t) GPIO_CC1101_GDO2 },
     { "CHANGE", CHANGE },
diff --git a/tasmota/include/tasmota_template.h b/tasmota/include/tasmota_template.h
index 6d4226967..6e49061b6 100644
--- a/tasmota/include/tasmota_template.h
+++ b/tasmota/include/tasmota_template.h
@@ -229,6 +229,7 @@ enum UserSelectablePins {
   GPIO_I2C_SER_TX, GPIO_I2C_SER_RX,     // I2C via Serial using SC18IM704 protocol (xdrv74)
   GPIO_TM1640CLK, GPIO_TM1640DIN,       // TM1640 (16 x seven-segment LED controler)
   GPIO_TWAI_TX, GPIO_TWAI_RX, GPIO_TWAI_BO, GPIO_TWAI_CLK,  // ESP32 TWAI serial interface
+  GPIO_C8_CO2_5K_TX, GPIO_C8_CO2_5K_RX, // C8-CO2-5K CO2 Sensor
   GPIO_SENSOR_END };
 
 // Error as warning to rethink GPIO usage with max 2045
@@ -504,7 +505,8 @@ const char kSensorNames[] PROGMEM =
   D_SENSOR_LD2410S_TX "|" D_SENSOR_LD2410S_RX "|"
   D_SENSOR_I2C_SER_TX "|" D_SENSOR_I2C_SER_RX "|"
   D_SENSOR_TM1640_CLK "|" D_SENSOR_TM1640_DIN "|"
-  D_SENSOR_TWAI_TX "|" D_SENSOR_TWAI_RX "|" D_SENSOR_TWAI_BO "|" D_SENSOR_TWAI_CLK
+  D_SENSOR_TWAI_TX "|" D_SENSOR_TWAI_RX "|" D_SENSOR_TWAI_BO "|" D_SENSOR_TWAI_CLK "|"
+  D_SENSOR_C8_CO2_5K_TX "|" D_SENSOR_C8_CO2_5K_RX
   ;
 
 const char kSensorNamesFixed[] PROGMEM =
@@ -1141,6 +1143,11 @@ const uint16_t kGpioNiceList[] PROGMEM = {
 #ifdef USE_WOOLIIS
   AGPIO(GPIO_WOOLIIS_RX),                        // Wooliis Battery capacity monitor Serial interface
 #endif
+#ifdef USE_C8_CO2_5K
+  AGPIO(GPIO_C8_CO2_5K_TX),                      // SC8-CO2-5K Serial interface
+  AGPIO(GPIO_C8_CO2_5K_RX),                      // SC8-CO2-5K Serial interface
+#endif
+
 
 #ifdef ESP32
 #ifdef USE_ESP32_TWAI
diff --git a/tasmota/language/af_AF.h b/tasmota/language/af_AF.h
index 52816ffb8..98a31b0e3 100644
--- a/tasmota/language/af_AF.h
+++ b/tasmota/language/af_AF.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/bg_BG.h b/tasmota/language/bg_BG.h
index 400b15038..51b4f4ac3 100644
--- a/tasmota/language/bg_BG.h
+++ b/tasmota/language/bg_BG.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "А"
diff --git a/tasmota/language/ca_AD.h b/tasmota/language/ca_AD.h
index 2dcb965b0..6e9f6f999 100644
--- a/tasmota/language/ca_AD.h
+++ b/tasmota/language/ca_AD.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/cs_CZ.h b/tasmota/language/cs_CZ.h
index 5d1044643..ddfdbbf6e 100644
--- a/tasmota/language/cs_CZ.h
+++ b/tasmota/language/cs_CZ.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/de_DE.h b/tasmota/language/de_DE.h
index bcdf4b1b1..c1ea4dd30 100644
--- a/tasmota/language/de_DE.h
+++ b/tasmota/language/de_DE.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/el_GR.h b/tasmota/language/el_GR.h
index 8e48c1f37..5eeecb716 100644
--- a/tasmota/language/el_GR.h
+++ b/tasmota/language/el_GR.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/en_GB.h b/tasmota/language/en_GB.h
index eeacbf121..43fc302aa 100644
--- a/tasmota/language/en_GB.h
+++ b/tasmota/language/en_GB.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 Rx"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/es_ES.h b/tasmota/language/es_ES.h
index 28e364a1d..4c243c834 100644
--- a/tasmota/language/es_ES.h
+++ b/tasmota/language/es_ES.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/fr_FR.h b/tasmota/language/fr_FR.h
index 332fb061e..b89b5476d 100644
--- a/tasmota/language/fr_FR.h
+++ b/tasmota/language/fr_FR.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 
 // Units
diff --git a/tasmota/language/fy_NL.h b/tasmota/language/fy_NL.h
index 1ef5d94b5..b3df21bbb 100644
--- a/tasmota/language/fy_NL.h
+++ b/tasmota/language/fy_NL.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/he_HE.h b/tasmota/language/he_HE.h
index b5cffe74a..06923f13c 100644
--- a/tasmota/language/he_HE.h
+++ b/tasmota/language/he_HE.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/hu_HU.h b/tasmota/language/hu_HU.h
index 03ec9dbf0..69962aad5 100644
--- a/tasmota/language/hu_HU.h
+++ b/tasmota/language/hu_HU.h
@@ -1028,6 +1028,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/it_IT.h b/tasmota/language/it_IT.h
index 787f396fb..a80c8fc6d 100644
--- a/tasmota/language/it_IT.h
+++ b/tasmota/language/it_IT.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX              "LoxO2 - RX"
 #define D_GPIO_MAGIC_SWITCH             "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX             "Wooliis - RX"
+#define D_SENSOR_C8_CO2_5K_RX           "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX           "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE                     "A"
diff --git a/tasmota/language/ko_KO.h b/tasmota/language/ko_KO.h
index 686887445..96daa238c 100644
--- a/tasmota/language/ko_KO.h
+++ b/tasmota/language/ko_KO.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/nl_NL.h b/tasmota/language/nl_NL.h
index 50be900eb..d7b9bc0f0 100644
--- a/tasmota/language/nl_NL.h
+++ b/tasmota/language/nl_NL.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/pl_PL.h b/tasmota/language/pl_PL.h
index f74f11e15..b0e87e711 100644
--- a/tasmota/language/pl_PL.h
+++ b/tasmota/language/pl_PL.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/pt_BR.h b/tasmota/language/pt_BR.h
index 41c941ae3..8fdb5522a 100644
--- a/tasmota/language/pt_BR.h
+++ b/tasmota/language/pt_BR.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/pt_PT.h b/tasmota/language/pt_PT.h
index 1018ba3ee..456a63ba3 100644
--- a/tasmota/language/pt_PT.h
+++ b/tasmota/language/pt_PT.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/ro_RO.h b/tasmota/language/ro_RO.h
index 974d34070..9a8d8847e 100644
--- a/tasmota/language/ro_RO.h
+++ b/tasmota/language/ro_RO.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/ru_RU.h b/tasmota/language/ru_RU.h
index 41253820f..43cfba06a 100644
--- a/tasmota/language/ru_RU.h
+++ b/tasmota/language/ru_RU.h
@@ -1022,6 +1022,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "А"
diff --git a/tasmota/language/sk_SK.h b/tasmota/language/sk_SK.h
index 11d6229d4..57998b8d9 100644
--- a/tasmota/language/sk_SK.h
+++ b/tasmota/language/sk_SK.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/sv_SE.h b/tasmota/language/sv_SE.h
index 3bb0f11be..338447aea 100644
--- a/tasmota/language/sv_SE.h
+++ b/tasmota/language/sv_SE.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/tr_TR.h b/tasmota/language/tr_TR.h
index c9d1b1317..60ca0cbb0 100644
--- a/tasmota/language/tr_TR.h
+++ b/tasmota/language/tr_TR.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/uk_UA.h b/tasmota/language/uk_UA.h
index fbbe2b4b6..3ec1df400 100644
--- a/tasmota/language/uk_UA.h
+++ b/tasmota/language/uk_UA.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE                    "А"
diff --git a/tasmota/language/vi_VN.h b/tasmota/language/vi_VN.h
index 51b28ae2b..97297a248 100644
--- a/tasmota/language/vi_VN.h
+++ b/tasmota/language/vi_VN.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/zh_CN.h b/tasmota/language/zh_CN.h
index 5bc984814..065864175 100644
--- a/tasmota/language/zh_CN.h
+++ b/tasmota/language/zh_CN.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "A"
diff --git a/tasmota/language/zh_TW.h b/tasmota/language/zh_TW.h
index 00a341461..4bda42c0f 100644
--- a/tasmota/language/zh_TW.h
+++ b/tasmota/language/zh_TW.h
@@ -1021,6 +1021,8 @@
 #define D_SENSOR_LOX_O2_RX     "LoxO2 RX"
 #define D_GPIO_MAGIC_SWITCH    "MagicSwitch"
 #define D_SENSOR_WOOLIIS_RX    "Wooliis Rx"
+#define D_SENSOR_C8_CO2_5K_RX  "C8-CO2-5K Rx"
+#define D_SENSOR_C8_CO2_5K_TX  "C8-CO2-5K Tx"
 
 // Units
 #define D_UNIT_AMPERE "安培"
diff --git a/tasmota/my_user_config.h b/tasmota/my_user_config.h
index bee454c7b..6af3146ac 100644
--- a/tasmota/my_user_config.h
+++ b/tasmota/my_user_config.h
@@ -902,6 +902,7 @@
 //  #define GM861_DECODE_AIM                       // Decode AIM-id (+0k3 code)
 //  #define GM861_HEARTBEAT                        // Enable heartbeat (+0k2 code)
 //#define USE_WOOLIIS                              // Add support for Wooliis Hall Effect Coulometer or Battery capacity monitor (+1k6 code)
+//#define USE_C8_CO2_5K                            // Add support for C8-CO2-5K CO2 Sensor (+4k3 code)
 //#define USE_DALI                                 // Add support for DALI gateway (+5k code)
 
 // -- Power monitoring sensors --------------------
diff --git a/tasmota/tasmota_support/support_features.ino b/tasmota/tasmota_support/support_features.ino
index d0a41e657..e8a8cf007 100644
--- a/tasmota/tasmota_support/support_features.ino
+++ b/tasmota/tasmota_support/support_features.ino
@@ -937,8 +937,10 @@ constexpr uint32_t feature[] = {
 #ifdef USE_ESP32_TWAI
   0x00000800 |  // xdrv_91_esp32_twai.ino
 #endif
-//  0x00001000 |  // 
-//  0x00002000 |  // 
+#ifdef USE_C8_CO2_5K
+  0x00001000 |  // xsns_117_c8_co2_5k.ino
+#endif
+//  0x00002000 |  //
 //  0x00004000 |  // 
 //  0x00008000 |  // 
 //  0x00010000 |  // 
diff --git a/tasmota/tasmota_xsns_sensor/xsns_117_c8_co2_5k.ino b/tasmota/tasmota_xsns_sensor/xsns_117_c8_co2_5k.ino
new file mode 100644
index 000000000..eb8cd6c97
--- /dev/null
+++ b/tasmota/tasmota_xsns_sensor/xsns_117_c8_co2_5k.ino
@@ -0,0 +1,153 @@
+/*
+  xsns_117_c8_co2_5k.ino - SC8-CO2-5K CO2 sensor support for Tasmota
+
+  Copyright (C) 2025  Jeroen Vermeulen
+
+  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_C8_CO2_5K
+/*********************************************************************************************\
+ * SC8-CO2-5K - CO2 sensor
+ *
+ * Inspired by:
+ *   https://community.openenergymonitor.org/uploads/short-url/tDiJ3EWtv7OlcHZnNgX3dFv8Cpv.pdf
+ *   https://spezifisch.codeberg.page/posts/2022-08-23/co2-sensor-reverse-engineering/
+ *   https://github.com/Jaron0211/C8_master
+ \********************************************************************************************/
+
+#define XSNS_117 117
+
+#include <TasmotaSerial.h>
+
+#ifndef CO2_LOW
+#define CO2_LOW 800 // Below this CO2 value show green light
+#endif
+#ifndef CO2_HIGH
+#define CO2_HIGH 1200 // Above this CO2 value show red light
+#endif
+
+#define C8CO2_READ_TIMEOUT 400
+const char c8cp2_type[] = "C8-CO2-5K";
+
+static uint8_t c8co2_buffer[16] = {0};
+TasmotaSerial *c8co2_serial = nullptr;
+uint16_t c8co2_ppm = 0;
+
+void C8CO2_Init()
+{
+    if (PinUsed(GPIO_C8_CO2_5K_RX))
+    {
+        int txPin = PinUsed(GPIO_C8_CO2_5K_TX) ? Pin(GPIO_C8_CO2_5K_TX) : -1;
+        c8co2_serial = new TasmotaSerial(Pin(GPIO_C8_CO2_5K_RX), txPin, 1);
+        if (c8co2_serial->begin(9600))
+        {
+            if (c8co2_serial->hardwareSerial())
+                ClaimSerial();
+#ifdef ESP32
+            AddLog(LOG_LEVEL_DEBUG, PSTR("C8-CO2-5K: Serial UART%d"), c8co2_serial->getUart());
+#endif
+        }
+        AddLog(LOG_LEVEL_DEBUG, PSTR("C8-CO2-5K: Sensor serial ready"));
+    }
+}
+
+void C8CO2_EverySecond()
+{
+    unsigned long start = millis();
+    while ((millis() - start) < C8CO2_READ_TIMEOUT && c8co2_serial->available() > 0)
+    {
+        c8co2_buffer[0] = c8co2_buffer[1];
+        c8co2_buffer[1] = c8co2_serial->read();
+
+        if (c8co2_buffer[0] != 0x42 || c8co2_buffer[1] != 0x4D) // Check for header bytes
+            continue;
+
+        if (c8co2_serial->readBytes(&c8co2_buffer[2], 14) != 14)
+        {
+            AddLog(LOG_LEVEL_INFO, PSTR("C8-CO2-5K: ERROR Incomplete data received"));
+            return;
+        }
+
+        uint8_t sum = 0;
+        for (int i = 0; i < 15; i++)
+        {
+            sum += c8co2_buffer[i];
+        }
+        if (sum != c8co2_buffer[15])
+        {
+            AddLog(LOG_LEVEL_INFO, PSTR("C8-CO2-5K: ERROR Checksum mismatch"));
+            return;
+        }
+
+        c8co2_ppm = (c8co2_buffer[6] << 8) | c8co2_buffer[7];
+        AddLog(LOG_LEVEL_DEBUG, PSTR("C8-CO2-5K Sensor: %d ppm"), c8co2_ppm);
+#ifdef USE_LIGHT
+        LightSetSignal(CO2_LOW, CO2_HIGH, c8co2_ppm);
+#endif // USE_LIGHT
+        return;
+    }
+}
+
+void C8CO2_Show(bool json)
+{
+    if (json)
+    {
+        ResponseAppend_P(PSTR(",\"%s\":{\"" D_JSON_CO2 "\":%d}"), c8cp2_type, c8co2_ppm);
+#ifdef USE_DOMOTICZ
+        if (0 == TasmotaGlobal.tele_period)
+        {
+            DomoticzSensor(DZ_AIRQUALITY, c8co2_ppm);
+        }
+#endif // USE_DOMOTICZ
+#ifdef USE_WEBSERVER
+    }
+    else
+    {
+        WSContentSend_PD(HTTP_SNS_CO2, c8cp2_type, c8co2_ppm);
+#endif // USE_WEBSERVER
+    }
+}
+
+/*********************************************************************************************\
+ * Interface
+\*********************************************************************************************/
+
+bool Xsns117(uint32_t function)
+{
+    if (FUNC_INIT == function)
+    {
+        C8CO2_Init();
+    }
+    else if (c8co2_serial)
+    {
+        switch (function)
+        {
+        case FUNC_EVERY_SECOND:
+            C8CO2_EverySecond();
+            break;
+        case FUNC_JSON_APPEND:
+            C8CO2_Show(1);
+            break;
+#ifdef USE_WEBSERVER
+        case FUNC_WEB_SENSOR:
+            C8CO2_Show(0);
+            break;
+#endif // USE_WEBSERVER
+        }
+    }
+    return false;
+}
+
+#endif // USE_C8_CO2_5K
diff --git a/tools/decode-status.py b/tools/decode-status.py
index 17d957cfb..724d02f33 100755
--- a/tools/decode-status.py
+++ b/tools/decode-status.py
@@ -310,7 +310,7 @@ a_features = [[
     "USE_MAGIC_SWITCH","USE_PIPSOLAR","USE_GPIO_VIEWER","USE_AMSX915",
     "USE_SPI_LORA","USE_SPL06_007","USE_QMP6988","USE_WOOLIIS",
     "USE_HX711_M5SCALES","USE_RX8010","USE_PCF85063","USE_ESP32_TWAI",
-    "","","","",
+    "USE_C8_CO2_5K","","","",
     "","","","",
     "","","","",
     "","","","",
diff --git a/tools/lv_gpio/lv_gpio_enum.h b/tools/lv_gpio/lv_gpio_enum.h
index ad7df0fb7..f8a74084b 100644
--- a/tools/lv_gpio/lv_gpio_enum.h
+++ b/tools/lv_gpio/lv_gpio_enum.h
@@ -367,4 +367,7 @@ RN2XX3_RST = GPIO_RN2XX3_RST
 
 WOOLIIS_RX = GPIO_WOOLIIS_RX
 
+C8_CO2_5K_TX = GPIO_C8_CO2_5K_TX
+C8_CO2_5K_RX = GPIO_C8_CO2_5K_RX
+
 SENSOR_END = GPIO_SENSOR_END