diff --git a/src/gas/gas.h b/src/gas/gas.h
index b32647c4..bc2e397e 100644
--- a/src/gas/gas.h
+++ b/src/gas/gas.h
@@ -34,7 +34,6 @@ struct thresholdContext {
 };
 
 namespace upm {
-
 /**
  * @brief Gas Sensor Library
  *
@@ -42,6 +41,7 @@ namespace upm {
  * sampling, threshold checking, a basic printing function and a standard read function.
  *
  * @defgroup gas libupm-gas
+ * @ingroup seeed analog gaseous
  */
 class Gas {
     public:
diff --git a/src/gas/mq2.h b/src/gas/mq2.h
index b9619147..08175676 100644
--- a/src/gas/mq2.h
+++ b/src/gas/mq2.h
@@ -28,18 +28,24 @@
 #include "gas.h"
 
 namespace upm {
-    /**
-     * @brief C++ API for MQ2 gas sensor
-     *
-     * The Grove - Gas Sensor (MQ2) module is useful for gas leakage detecting
-     * (in home and industry). It can detect LPG, i-butane, methane, alcohol,
-     * Hydrogen, smoke and other combustible gases. It's a medium sensitivity
-     * sensor with a detect concentration of 300-10000 ppm.
-     *
-     * @ingroup gas analog
-     * @snippet mq2.cxx Interesting
-     * @image html mq2-5.jpeg
-     */
+  /**
+   * @library gas
+   * @sensor mq2
+   * @comname Grove MQ2 gas sensor
+   * @type gaseous
+   * @man seeed
+   * @con analog
+   *
+   * @brief C++ API for MQ2 gas sensor
+   *
+   * The Grove - Gas Sensor (MQ2) module is useful for gas leakage detecting
+   * (in home and industry). It can detect LPG, i-butane, methane, alcohol,
+   * Hydrogen, smoke and other combustible gases. It's a medium sensitivity
+   * sensor with a detect concentration of 300-10000 ppm.
+   *
+   * @image html mq2-5.jpeg
+   * @snippet mq2.cxx Interesting
+   */
     class MQ2 : public Gas {
         public:
             /**
diff --git a/src/gas/mq3.h b/src/gas/mq3.h
index 49cefe05..aa31a591 100644
--- a/src/gas/mq3.h
+++ b/src/gas/mq3.h
@@ -28,18 +28,24 @@
 #include "gas.h"
 
 namespace upm {
-    /**
-     * @brief C++ API for MQ3 gas sensor
-     *
-     * The Grove MQ3 Gas Sensor module is useful for gas leakage detecting (in
-     * home and industry). It can detect Alcohol Vapour and Benzine. It's
-     * highly sensitive but has a long warm-up time of about 1 minute. It's
-     * detect rate is of 0.04-4 mg/L Alcohol.
-     *
-     * @ingroup gas analog
-     * @snippet mq3.cxx Interesting
-     * @image html mq3-9.jpeg
-     */
+  /**
+   * @library gas
+   * @sensor mq3
+   * @comname Grove MQ3 gas sensor
+   * @type gaseous
+   * @man seeed
+   * @con analog
+   *
+   * @brief C++ API for MQ3 gas sensor
+   *
+   * The Grove MQ3 Gas Sensor module is useful for gas leakage detecting (in
+   * home and industry). It can detect Alcohol Vapour and Benzine. It's
+   * highly sensitive but has a long warm-up time of about 1 minute. It's
+   * detect rate is of 0.04-4 mg/L Alcohol.
+   *
+   * @image html mq3-9.jpeg
+   * @snippet mq3.cxx Interesting
+   */
     class MQ3 : public Gas {
         public:
             /**
diff --git a/src/gas/mq5.h b/src/gas/mq5.h
index 5adf7d0e..f8ab0c9e 100644
--- a/src/gas/mq5.h
+++ b/src/gas/mq5.h
@@ -28,18 +28,24 @@
 #include "gas.h"
 
 namespace upm {
-    /**
-     * @brief C++ API for MQ5 gas sensor
-     *
-     * The Grove - Gas Sensor (MQ5) module is useful for gas leakage detecting
-     * (in home and industry). It can detect LPG, natural gas, town gas and so
-     * on. It is highly sensitive and has a detection concentration of
-     * 300-10000 ppm.
-     *
-     * @ingroup gas analog
-     * @snippet mq5.cxx Interesting
-     * @image html mq2-5.jpeg
-     */
+  /**
+   * @library gas
+   * @sensor mq5
+   * @comname Grove MQ5 gas sensor
+   * @type gaseous
+   * @man seeed
+   * @con analog
+   *
+   * @brief C++ API for MQ5 gas sensor
+   *
+   * The Grove - Gas Sensor (MQ5) module is useful for gas leakage detecting
+   * (in home and industry). It can detect LPG, natural gas, town gas and so
+   * on. It is highly sensitive and has a detection concentration of
+   * 300-10000 ppm.
+   *
+   * @image html mq2-5.jpeg
+   * @snippet mq5.cxx Interesting
+   */
     class MQ5 : public Gas {
         public:
             /**
diff --git a/src/gas/mq9.h b/src/gas/mq9.h
index 3e2145ab..809718be 100644
--- a/src/gas/mq9.h
+++ b/src/gas/mq9.h
@@ -28,17 +28,23 @@
 #include "gas.h"
 
 namespace upm {
-    /**
-     * @brief C++ API for MQ9 gas sensor
-     *
-     * The Grove MQ9 Gas Sensor module is useful for gas leakage detecting (in
-     * home and industry). It can detect Carbon Monoxide, Coal Gas and
-     * Liquefied Gas. It's sensitivity is 10-1000 ppm CO, 100-10000 ppm Gas.
-     *
-     * @ingroup gas analog
-     * @snippet mq9.cxx Interesting
-     * @image html mq3-9.jpeg
-     */
+  /**
+   * @library gas
+   * @sensor mq9
+   * @comname Grove MQ9 gas sensor
+   * @type gaseous
+   * @man seeed
+   * @con analog
+   *
+   * @brief C++ API for MQ9 gas sensor
+   *
+   * The Grove MQ9 Gas Sensor module is useful for gas leakage detecting (in
+   * home and industry). It can detect Carbon Monoxide, Coal Gas and
+   * Liquefied Gas. It's sensitivity is 10-1000 ppm CO, 100-10000 ppm Gas.
+   *
+   * @image html mq3-9.jpeg
+   * @snippet mq9.cxx Interesting
+   */
     class MQ9 : public Gas {
         public:
             /**
diff --git a/src/gas/tp401.h b/src/gas/tp401.h
index e47f99a2..de5070a4 100644
--- a/src/gas/tp401.h
+++ b/src/gas/tp401.h
@@ -28,21 +28,28 @@
 #include "gas.h"
 
 namespace upm {
-    /**
-     * @brief C++ API for Grove TP401 Air Quality Sensor
-     *
-     * The Grove TP401 Air Quality Sensor module is useful for monitoring air purity indoors.
-     * It can detect CO and a wide range of other harmful gases, but due to limited sensing
-     * range should be used only when qualitative results are needed. Example applications
-     * are air recirculation, ventilation systems, and refreshing sprayers.
-     * The sensor is linear and should be roughly sensitive to 0 ~ 20 ppm CO from 0 ~ 4V.
-     * Also note that the sensor requires 2-3 minutes to warm up initially and 48 hours of
-     * operation to stabilize completely.
-     *
-     * @ingroup gas analog
-     * @snippet tp401.cxx Interesting
-     * @image html tp401.jpeg
-     */
+  /**
+   * @library gas
+   * @sensor tp401
+   * @comname Grove Air Quality Sensor
+   * @altname TP401
+   * @type gaseous
+   * @man seeed
+   * @con analog
+   *
+   * @brief C++ API for Grove TP401 Air Quality Sensor
+   *
+   * The Grove TP401 Air Quality Sensor module is useful for monitoring air purity indoors.
+   * It can detect CO and a wide range of other harmful gases, but due to limited sensing
+   * range should be used only when qualitative results are needed. Example applications
+   * are air recirculation, ventilation systems, and refreshing sprayers.
+   * The sensor is linear and should be roughly sensitive to 0 ~ 20 ppm CO from 0 ~ 4V.
+   * Also note that the sensor requires 2-3 minutes to warm up initially and 48 hours of
+   * operation to stabilize completely.
+   *
+   * @image html tp401.jpeg
+   * @snippet tp401.cxx Interesting
+   */
     class TP401 : public Gas {
         public:
             /**