diff --git a/src/knx/group_object/dpt/dpt.h b/src/knx/group_object/dpt/dpt.h
index 6c24bcd..30e2c3b 100644
--- a/src/knx/group_object/dpt/dpt.h
+++ b/src/knx/group_object/dpt/dpt.h
@@ -3,9 +3,6 @@
 #include "../group_object.h"
 namespace Knx
 {
-#define DPT_Switch Dpt(1, 1)
-#define DPT_Bool Dpt(1, 2)
-#define DPT_Enable Dpt(1, 3)
 #define DPT_Ramp Dpt(1, 4)
 #define DPT_Alarm Dpt(1, 5)
 #define DPT_BinaryValue Dpt(1, 6)
diff --git a/src/knx/group_object/dpt/dpt1.cpp b/src/knx/group_object/dpt/dpt1.cpp
index ec3a9f1..63d8143 100644
--- a/src/knx/group_object/dpt/dpt1.cpp
+++ b/src/knx/group_object/dpt/dpt1.cpp
@@ -2,9 +2,12 @@
 
 #include "dptconvert.h"
 
-Knx::Dpt1::Dpt1() {}
+Knx::Dpt1::Dpt1(unsigned short subgroup /*= 0*/) : Dpt(1, subgroup) {}
 
-Knx::Dpt1::Dpt1(bool value) : _value(value) {}
+Knx::Dpt1::Dpt1(bool value) : Dpt1()
+{
+    _value = value;
+}
 
 Knx::Go_SizeCode Knx::Dpt1::size() const
 {
@@ -26,7 +29,7 @@ void Knx::Dpt1::value(bool value)
     _value = value;
 }
 
-bool Knx::Dpt1::value()
+bool Knx::Dpt1::value() const
 {
     return _value;
 }
@@ -42,3 +45,75 @@ Knx::Dpt1& Knx::Dpt1::operator=(const bool value)
     _value = value;
     return *this;
 }
+
+Knx::DPT_Switch::DPT_Switch() : Dpt1()
+{
+    subGroup = 1;
+}
+
+Knx::DPT_Switch::DPT_Switch(SwitchValue value) : Dpt1(value == On)
+{
+    subGroup = 1;
+}
+
+void Knx::DPT_Switch::value(SwitchValue value)
+{
+    Dpt1::value(value == On);
+}
+
+Knx::DPT_Switch::SwitchValue Knx::DPT_Switch::value() const
+{
+    return Dpt1::value() ? On : Off;
+}
+
+Knx::DPT_Switch::operator Knx::DPT_Switch::SwitchValue() const
+{
+    return value();
+}
+
+Knx::DPT_Switch& Knx::DPT_Switch::operator=(const Knx::DPT_Switch::SwitchValue value)
+{
+    Dpt1::value(value == On);
+    return *this;
+}
+
+Knx::DPT_Bool::DPT_Bool() : Dpt1()
+{
+    subGroup = 2;
+}
+
+Knx::DPT_Bool::DPT_Bool(bool value) : DPT_Bool()
+{
+    Dpt1::value(value);
+}
+
+Knx::DPT_Enable::DPT_Enable() : Dpt1()
+{
+    subGroup = 3;
+}
+
+Knx::DPT_Enable::DPT_Enable(EnableValue value) : Dpt1(value == Enable)
+{
+    subGroup = 3;
+}
+
+void Knx::DPT_Enable::value(EnableValue value)
+{
+    Dpt1::value(value == Enable);
+}
+
+Knx::DPT_Enable::EnableValue Knx::DPT_Enable::value() const
+{
+    return Dpt1::value() ? Enable : Disable;
+}
+
+Knx::DPT_Enable::operator Knx::DPT_Enable::EnableValue() const
+{
+    return value();
+}
+
+Knx::DPT_Enable& Knx::DPT_Enable::operator=(const Knx::DPT_Enable::EnableValue value)
+{
+    Dpt1::value(value == Enable);
+    return *this;
+}
\ No newline at end of file
diff --git a/src/knx/group_object/dpt/dpt1.h b/src/knx/group_object/dpt/dpt1.h
index 9e4bbcf..4d37ffb 100644
--- a/src/knx/group_object/dpt/dpt1.h
+++ b/src/knx/group_object/dpt/dpt1.h
@@ -5,7 +5,7 @@ namespace Knx
     class Dpt1: public Dpt
     {
         public:
-            Dpt1();
+            Dpt1(unsigned short subgroup = 0);
             Dpt1(bool value);
             Go_SizeCode size() const override;
 
@@ -13,10 +13,49 @@ namespace Knx
             virtual void decode(uint8_t* data) override;
 
             void value(bool value);
-            bool value();
+            bool value() const;
             operator bool() const;
             Dpt1& operator=(const bool value);
         private:
             bool _value;
     };
+
+    class DPT_Switch : public Dpt1
+    {
+        public:
+            enum SwitchValue
+            {
+                Off, On
+            };
+
+            DPT_Switch();
+            DPT_Switch(SwitchValue value);
+            void value(SwitchValue value);
+            SwitchValue value() const;
+            operator SwitchValue() const;
+            DPT_Switch& operator=(const SwitchValue value);
+    };
+
+    class DPT_Bool : public Dpt1
+    {
+        public:
+            DPT_Bool();
+            DPT_Bool(bool value);
+    };
+
+    class DPT_Enable : public Dpt1
+    {
+        public:
+            enum EnableValue
+            {
+                Disable, Enable
+            };
+
+            DPT_Enable();
+            DPT_Enable(EnableValue value);
+            void value(EnableValue value);
+            EnableValue value() const;
+            operator EnableValue() const;
+            DPT_Enable& operator=(const EnableValue value);
+    };
 }
\ No newline at end of file
diff --git a/src/knx/group_object/dpt/dpt9.cpp b/src/knx/group_object/dpt/dpt9.cpp
index cb1042e..cea3652 100644
--- a/src/knx/group_object/dpt/dpt9.cpp
+++ b/src/knx/group_object/dpt/dpt9.cpp
@@ -2,9 +2,9 @@
 
 #include "dptconvert.h"
 
-Knx::Dpt9::Dpt9() {}
+Knx::Dpt9::Dpt9() { mainGroup = 9; }
 
-Knx::Dpt9::Dpt9(float value) : _value(value) {}
+Knx::Dpt9::Dpt9(float value) : _value(value) { mainGroup = 9; }
 
 Knx::Go_SizeCode Knx::Dpt9::size() const
 {
@@ -29,7 +29,7 @@ void Knx::Dpt9::value(float value)
     _value = value;
 }
 
-bool Knx::Dpt9::value()
+float Knx::Dpt9::value() const
 {
     return _value;
 }
diff --git a/src/knx/group_object/dpt/dpt9.h b/src/knx/group_object/dpt/dpt9.h
index fe9eb05..6c804a2 100644
--- a/src/knx/group_object/dpt/dpt9.h
+++ b/src/knx/group_object/dpt/dpt9.h
@@ -13,7 +13,7 @@ namespace Knx
             virtual void decode(uint8_t* data) override;
 
             void value(float value);
-            bool value();
+            float value() const;
             operator float() const;
             Dpt9& operator=(const float value);
         private: