diff --git a/scribbles_and_notes/pin_interface_CRTP_style/PIN_modeling.cpp b/scribbles_and_notes/pin_interface_CRTP_style/PIN_modeling.cpp
deleted file mode 100644
index 84c524a..0000000
--- a/scribbles_and_notes/pin_interface_CRTP_style/PIN_modeling.cpp
+++ /dev/null
@@ -1,28 +0,0 @@
-#include <memory>
-
-struct Pin
-{
-    virtual void set(bool logic);
-
-    virtual void toggle();
-
-    virtual bool get(void);
-};
-
-// https://www.modernescpp.com/index.php/c-is-still-lazy
-
-// curiously recurring template pattern
-template <typename T>
-struct PinCRTP : public Pin
-{
-    virtual override set(bool logic)
-    {
-        static_cast<>
-    }
-};
-
-
-int main(void)
-{
-    return 0;
-}
\ No newline at end of file
diff --git a/scribbles_and_notes/pin_interface_CRTP_style/pin_modleing_with_CRTP/Makefile b/scribbles_and_notes/pin_interface_CRTP_style/pin_modleing_with_CRTP/Makefile
new file mode 100644
index 0000000..38e5ad5
--- /dev/null
+++ b/scribbles_and_notes/pin_interface_CRTP_style/pin_modleing_with_CRTP/Makefile
@@ -0,0 +1,24 @@
+cpp_src = $(wildcard *.cpp) 
+cpp_src += $(wildcard ./utils/*.cpp)
+cpp_src += $(wildcard ./driver/*.cpp)
+
+cpp_obj = $(cpp_src:.cpp=.o)
+c_obj = $(c_src:.c=.o)
+CC = g++ 
+CFLAGS = -Wall -pedantic -li2c 
+LDFLAGS = 
+EXEC = runtest
+
+
+all : $(EXEC)
+
+$(EXEC): $(cpp_obj) $(c_obj)
+	$(CC) -o $@ $^ $(LDFLAGS) 
+ 
+clean: 
+	rm -rf $(c_obj) $(cpp_obj) $(EXEC)
+	clear
+
+cleanall: 
+	rm -rf $(c_obj) $(cpp_obj) $(EXEC)
+	clear
diff --git a/scribbles_and_notes/pin_interface_CRTP_style/pin_modleing_with_CRTP/main.cpp b/scribbles_and_notes/pin_interface_CRTP_style/pin_modleing_with_CRTP/main.cpp
new file mode 100644
index 0000000..0c05c7f
--- /dev/null
+++ b/scribbles_and_notes/pin_interface_CRTP_style/pin_modleing_with_CRTP/main.cpp
@@ -0,0 +1,113 @@
+#include <memory>
+#include <iostream>
+
+// https://www.modernescpp.com/index.php/c-is-still-lazy
+
+//
+//  CRTP base class of pin
+//
+
+/*
+    avoiding virtual call (static polymorphism)
+*/
+
+template <typename Derived>
+struct PinBase
+{
+
+    void set(bool logic)
+    {
+        static_cast<Derived*>(this)->setImp(logic);
+    }
+
+    void toggle()
+    {
+        static_cast<Derived*>(this)->toggleImp();
+    }
+
+    bool get(void)
+    {
+        return static_cast<Derived*>(this)->getImp();
+    }
+
+    private:
+
+    //
+    // base implementations
+    //
+
+    void setImp()
+    {
+        std::cout << "base implementation of set()!" << std::endl;
+    }
+
+    void toggleImp()
+    {
+        std::cout << "base implementation of toggle()!" << std::endl;
+    }
+
+    bool getImp(void)
+    {
+        std::cout << "base implementation of get()!" << std::endl;
+        return true;
+    }
+};
+
+//
+//  implementations
+//
+
+struct STM32_Pin : PinBase<STM32_Pin>
+{
+    void setImp(bool logic)
+    {
+        std::cout << "stm32 pin set to " << logic << std::endl;
+    }
+
+    void toggleImp()
+    {
+        std::cout << "toggled stm32 pin" << std::endl;
+    }
+
+    bool getImp()
+    {
+        return true;
+    }
+};
+
+struct AVR_Pin : PinBase<AVR_Pin>
+{
+    void setImp(bool logic)
+    {
+        std::cout << "AVR pin set to " << logic << std::endl;
+    }
+
+    void toggleImp()
+    {
+        std::cout << "toggled AVR pin" << std::endl;
+    }
+
+    bool getImp()
+    {
+        return true;
+    }
+};
+
+template<typename T>
+void foo(T& base)
+{
+    base.set(true);
+    base.set(false);
+    base.toggle();
+}
+
+int main(void)
+{
+    STM32_Pin pin1;
+    AVR_Pin pin2;
+
+    foo(pin1);
+    foo(pin2);
+
+    return 0;
+}
\ No newline at end of file
diff --git a/scribbles_and_notes/pin_interface_CRTP_style/pin_modleing_with_CRTP/runtest b/scribbles_and_notes/pin_interface_CRTP_style/pin_modleing_with_CRTP/runtest
new file mode 100755
index 0000000..8f3b9a1
Binary files /dev/null and b/scribbles_and_notes/pin_interface_CRTP_style/pin_modleing_with_CRTP/runtest differ