add some convienience methods to Property class

src/knx/data_property.cpp

@@ -86,39 +86,21 @@ DataProperty::DataProperty(PropertyID id, bool writeEnable, PropertyDataType typ
                            uint16_t maxElements, uint8_t access, uint16_t value)
     : Property(id, writeEnable, type, maxElements, access)
 {
-    uint8_t elementSize = ElementSize();
+    Property::write(value);
-    if (elementSize == 2)
-    {
-        uint8_t data[elementSize];
-        pushWord(value, data);
-        write(1, 1, data);
-    }
 }
 
 DataProperty::DataProperty(PropertyID id, bool writeEnable, PropertyDataType type, 
                            uint16_t maxElements, uint8_t access, uint32_t value)
     : Property(id, writeEnable, type, maxElements, access)
 {
-    uint8_t elementSize = ElementSize();
+    Property::write(value);
-    if (elementSize == 4)
-    {
-        uint8_t data[elementSize];
-        pushInt(value, data);
-        write(1, 1, data);
-    }
 }
 
 DataProperty::DataProperty(PropertyID id, bool writeEnable, PropertyDataType type,
                            uint16_t maxElements, uint8_t access, uint8_t value)
     : Property(id, writeEnable, type, maxElements, access)
 {
-    uint8_t elementSize = ElementSize();
+    Property::write(value);
-    if (elementSize == 1)
-    {
-        uint8_t data[elementSize];
-        data[0] = value;
-        write(1, 1, data);
-    }
 }
 
 uint16_t DataProperty::saveSize()

src/knx/ip_parameter_object.cpp

@@ -100,12 +100,8 @@ uint32_t IpParameterObject::multicastAddress() const
 {
     const Property* prop = property(PID_ROUTING_MULTICAST_ADDRESS);
 
-    uint8_t data[4];
-    uint8_t count = prop->read(1, 1, data);
-
     uint32_t value = DEFAULT_MULTICAST_ADDR;
-    if (count == 1)
+    prop->read(value);
-        popInt(value, data);
 
     return value;
 }
@@ -114,8 +110,8 @@ uint8_t IpParameterObject::ttl() const
 {
     const Property* prop = property(PID_TTL);
 
-    uint8_t data[1];
+    uint8_t value = 0;
-    prop->read(1, 1, data);
+    prop->read(value);
-    return data[0];
+    return value;
 }
 #endif

src/knx/property.cpp

@@ -111,3 +111,73 @@ Property::Property(PropertyID id, bool writeEnable, PropertyDataType type,
 
 Property::~Property()
 {}
+
+
+uint8_t Property::read(uint8_t& value) const
+{
+    if (ElementSize() != 1)
+        return 0;
+    
+    return read(1, 1, &value);
+}
+
+
+uint8_t Property::read(uint16_t& value) const
+{
+    if (ElementSize() != 2)
+        return 0;
+
+    uint8_t data[2];
+    uint8_t count = read(1, 1, data);
+    if (count > 0)
+    {
+        popWord(value, data);
+    }
+    return count;
+}
+
+
+uint8_t Property::read(uint32_t& value) const
+{
+    if (ElementSize() != 4)
+        return 0;
+
+    uint8_t data[4];
+    uint8_t count = read(1, 1, data);
+    if (count > 0)
+    {
+        popInt(value, data);
+    }
+    return count;
+}
+
+
+uint8_t Property::write(uint8_t& value)
+{
+    if (ElementSize() != 1)
+        return 0;
+
+    return write(1, 1, &value);
+}
+
+
+uint8_t Property::write(uint16_t& value)
+{
+    if (ElementSize() != 2)
+        return 0;
+
+    uint8_t data[2];
+    pushWord(value, data);
+    return write(1, 1, data);
+}
+
+
+uint8_t Property::write(uint32_t& value)
+{
+    if (ElementSize() != 4)
+        return 0;
+
+    uint8_t data[4];
+    pushInt(value, data);
+    return write(1, 1, data);
+}

src/knx/property.h

@@ -238,6 +238,12 @@ class Property : public SaveRestore
     uint8_t ElementSize() const;
     virtual uint8_t read(uint16_t start, uint8_t count, uint8_t* data) const = 0;
     virtual uint8_t write(uint16_t start, uint8_t count, uint8_t* data) = 0;
+    uint8_t read(uint8_t& value) const;
+    uint8_t read(uint16_t& value) const;
+    uint8_t read(uint32_t& value) const;
+    uint8_t write(uint8_t& value);
+    uint8_t write(uint16_t& value);
+    uint8_t write(uint32_t& value);
   protected:
     PropertyID _id;
     bool _writeEnable;