diff --git a/01_blink/.vscode/c_cpp_properties.json b/01_blink/.vscode/c_cpp_properties.json
index d8747d6..ede8e1a 100644
--- a/01_blink/.vscode/c_cpp_properties.json
+++ b/01_blink/.vscode/c_cpp_properties.json
@@ -3,7 +3,8 @@
         {
             "name": "Linux GCC ARM",
             "includePath": [
-                "${workspaceFolder}/**"
+                "${workspaceFolder}/**",
+                "${workspaceFolder}/../../../pico-sdk/src/**"
             ],
             "defines": [],
             "compilerPath": "/usr/bin/gcc",
diff --git a/01_blink/CMakeLists.txt b/01_blink/CMakeLists.txt
index 1a005fb..4b4d62a 100644
--- a/01_blink/CMakeLists.txt
+++ b/01_blink/CMakeLists.txt
@@ -10,8 +10,8 @@ pico_sdk_init()
 add_executable(blink
     src/blink.c
 )
-pico_set_program_name(ProjectName "Blink")
-pico_set_program_version(ProjectName "0.1.0")
+pico_set_program_name(blink "Blink")
+pico_set_program_version(blink "0.1.0")
 
 pico_enable_stdio_usb(blink 1)
 pico_enable_stdio_uart(blink 0)
diff --git a/02_hello_serial/.vscode/c_cpp_properties.json b/02_hello_serial/.vscode/c_cpp_properties.json
index bc589aa..f59e754 100644
--- a/02_hello_serial/.vscode/c_cpp_properties.json
+++ b/02_hello_serial/.vscode/c_cpp_properties.json
@@ -3,7 +3,8 @@
         {
             "name": "Linux GCC ARM",
             "includePath": [
-                "${workspaceFolder}/**"
+                "${workspaceFolder}/**",
+                "${workspaceFolder}/../../../pico-sdk/src/**"
             ],
             "defines": [],
             "compilerPath": "/usr/bin/gcc",
diff --git a/02_hello_serial/CMakeLists.txt b/02_hello_serial/CMakeLists.txt
index 0511dfa..1d89167 100644
--- a/02_hello_serial/CMakeLists.txt
+++ b/02_hello_serial/CMakeLists.txt
@@ -11,8 +11,8 @@ add_executable(hello
     src/hello.c
 )
 
-pico_set_program_name(ProjectName "Hello Serial")
-pico_set_program_version(ProjectName "0.1.0")
+pico_set_program_name(hello "Hello Serial")
+pico_set_program_version(hello "0.1.0")
 
 pico_enable_stdio_usb(hello 1) # 표준 출력을 USB로
 pico_enable_stdio_uart(hello 0) # 표준 출력을 UART로, 안함.
diff --git a/03_data_types/.gitignore b/03_data_types/.gitignore
new file mode 100644
index 0000000..796b96d
--- /dev/null
+++ b/03_data_types/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/03_data_types/.vscode/c_cpp_properties.json b/03_data_types/.vscode/c_cpp_properties.json
new file mode 100644
index 0000000..f59e754
--- /dev/null
+++ b/03_data_types/.vscode/c_cpp_properties.json
@@ -0,0 +1,18 @@
+{
+    "configurations": [
+        {
+            "name": "Linux GCC ARM",
+            "includePath": [
+                "${workspaceFolder}/**",
+                "${workspaceFolder}/../../../pico-sdk/src/**"
+            ],
+            "defines": [],
+            "compilerPath": "/usr/bin/gcc",
+            "cStandard": "c11",
+            "cppStandard": "c++17",
+            "intelliSenseMode": "linux-gcc-arm",
+            "configurationProvider": "ms-vscode.cmake-tools"
+        }
+    ],
+    "version": 4
+}
\ No newline at end of file
diff --git a/03_data_types/CMakeLists.txt b/03_data_types/CMakeLists.txt
new file mode 100644
index 0000000..29095df
--- /dev/null
+++ b/03_data_types/CMakeLists.txt
@@ -0,0 +1,22 @@
+cmake_minimum_required(VERSION 3.13)
+
+include(pico_sdk_import.cmake)
+
+project(datatypes C CXX ASM)
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
+pico_sdk_init()
+
+add_executable(datatypes
+    src/datatypes.c
+)
+
+pico_set_program_name(datatypes "Data Types")
+pico_set_program_version(datatypes "0.1.0")
+
+pico_enable_stdio_usb(datatypes 1) # 표준 출력을 USB로
+pico_enable_stdio_uart(datatypes 0) # 표준 출력을 UART로, 안함.
+
+pico_add_extra_outputs(datatypes)
+
+target_link_libraries(datatypes pico_stdlib)
diff --git a/03_data_types/pico_sdk_import.cmake b/03_data_types/pico_sdk_import.cmake
new file mode 100644
index 0000000..28efe9e
--- /dev/null
+++ b/03_data_types/pico_sdk_import.cmake
@@ -0,0 +1,62 @@
+# This is a copy of <PICO_SDK_PATH>/external/pico_sdk_import.cmake
+
+# This can be dropped into an external project to help locate this SDK
+# It should be include()ed prior to project()
+
+if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
+    set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
+    message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT} AND (NOT PICO_SDK_FETCH_FROM_GIT))
+    set(PICO_SDK_FETCH_FROM_GIT $ENV{PICO_SDK_FETCH_FROM_GIT})
+    message("Using PICO_SDK_FETCH_FROM_GIT from environment ('${PICO_SDK_FETCH_FROM_GIT}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_PATH))
+    set(PICO_SDK_FETCH_FROM_GIT_PATH $ENV{PICO_SDK_FETCH_FROM_GIT_PATH})
+    message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
+endif ()
+
+set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the Raspberry Pi Pico SDK")
+set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of SDK from git if not otherwise locatable")
+set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
+
+if (NOT PICO_SDK_PATH)
+    if (PICO_SDK_FETCH_FROM_GIT)
+        include(FetchContent)
+        set(FETCHCONTENT_BASE_DIR_SAVE ${FETCHCONTENT_BASE_DIR})
+        if (PICO_SDK_FETCH_FROM_GIT_PATH)
+            get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
+        endif ()
+        FetchContent_Declare(
+                pico_sdk
+                GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                GIT_TAG master
+        )
+        if (NOT pico_sdk)
+            message("Downloading Raspberry Pi Pico SDK")
+            FetchContent_Populate(pico_sdk)
+            set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
+        endif ()
+        set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
+    else ()
+        message(FATAL_ERROR
+                "SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
+                )
+    endif ()
+endif ()
+
+get_filename_component(PICO_SDK_PATH "${PICO_SDK_PATH}" REALPATH BASE_DIR "${CMAKE_BINARY_DIR}")
+if (NOT EXISTS ${PICO_SDK_PATH})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' not found")
+endif ()
+
+set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
+if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the Raspberry Pi Pico SDK")
+endif ()
+
+set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the Raspberry Pi Pico SDK" FORCE)
+
+include(${PICO_SDK_INIT_CMAKE_FILE})
diff --git a/03_data_types/result.txt b/03_data_types/result.txt
new file mode 100644
index 0000000..e905921
--- /dev/null
+++ b/03_data_types/result.txt
@@ -0,0 +1,7 @@
+char 23 : size=1
+short 23 : size=2
+int 23 : size=4
+long 23 : size=4
+long long 23 : size=8
+float 3.140000 : size=4
+double 3.140000 : size=8
diff --git a/03_data_types/run b/03_data_types/run
new file mode 100755
index 0000000..91417d2
--- /dev/null
+++ b/03_data_types/run
@@ -0,0 +1,43 @@
+#!/usr/bin/bash
+export PICO_SDK_PATH="/media/elex/UltraFit/pico-sdk"
+
+function fn_clean {
+    if [ -d ./build ]
+    then
+        rm -r ./build    
+    fi
+    mkdir build
+}
+
+function fn_cmake {
+    cd build
+    cmake ..
+    cd ..
+}
+
+function fn_make {
+    cd build
+    make
+    cd ..
+}
+
+if [ -z $1 ]
+then
+    fn_clean
+    fn_cmake
+    fn_make
+elif [ $1 == 'clean' ]
+then
+    echo 'Cleaning build dir.'
+    fn_clean
+elif [ $1 == 'cmake' ]
+then
+    echo 'Exec cmake'
+    fn_cmake
+elif [ $1 == 'make' ]
+then
+    echo 'Exec make'
+    fn_make
+else
+    echo 'What do you want???'
+fi
diff --git a/03_data_types/src/datatypes.c b/03_data_types/src/datatypes.c
new file mode 100644
index 0000000..3ae07c8
--- /dev/null
+++ b/03_data_types/src/datatypes.c
@@ -0,0 +1,51 @@
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/gpio.h"
+#include "pico/binary_info.h"
+
+const uint LED_PIN = PICO_DEFAULT_LED_PIN;
+
+void print_data_types()
+{
+    char c = 23;
+    printf("char %d : size=%lu\n", c, sizeof(char)); // 1 byte
+
+    short s = 23;
+    printf("short %d : size=%lu\n", s, sizeof(short)); // 2 byte
+
+    int i = 23;
+    printf("int %d : size=%lu\n", i, sizeof(int)); // 4 byte
+
+    long l = 23L;
+    printf("long %ld : size=%lu\n", l, sizeof(long)); // 4 byte
+
+    long long ll = 23LL;
+    printf("long long %lld : size=%lu\n", ll, sizeof(long long)); // 8 byte
+
+    float f = 3.14F;
+    printf("float %f : size=%lu\n", f, sizeof(float)); // 4 byte
+
+    double d = 3.14;
+    printf("double %f : size=%lu\n", d, sizeof(double)); // 8 byte
+}
+
+int main()
+{
+    bi_decl(bi_program_description("Data types"));
+    bi_decl(bi_1pin_with_name(LED_PIN, "On-board LED"));
+
+    stdio_init_all();
+
+    gpio_init(LED_PIN);
+    gpio_set_dir(LED_PIN, GPIO_OUT);
+
+    while (true)
+    {
+        gpio_put(LED_PIN, true);
+        print_data_types();
+        sleep_ms(250);
+        gpio_put(LED_PIN, false);
+
+        sleep_ms(2000);
+    }
+}
\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..3391b87
--- /dev/null
+++ b/README.md
@@ -0,0 +1,9 @@
+# Raspberry PI Pico
+Examples
+
+
+------
+
+developed by Elex
+
+https://www.elex-project.com/
\ No newline at end of file