diff --git a/include/serial.h b/include/serial.h
index 3e34f07..f558802 100644
--- a/include/serial.h
+++ b/include/serial.h
@@ -22,6 +22,64 @@ namespace ranges = std::ranges;
 namespace views = std::views;
 
 namespace serial {
+template <typename... Types> struct _StrongType {};
+
+template <typename T> struct _StrongType<T> {
+    using Type = T;
+};
+
+template <typename Ta, typename Tb> struct _StrongType<Ta, Tb> {
+    using Type = decltype(true ? std::declval<Ta>() : std::declval<Tb>());
+};
+
+template <typename T, typename... Types> struct _StrongType<T, Types...> {
+    using Type =
+        typename _StrongType<T, typename _StrongType<Types...>::Type>::Type;
+};
+
+template <typename... Types>
+using _strongType_t = typename _StrongType<Types...>::Type;
+
+template <typename... Args> struct _IsCastable {};
+
+template <typename T> struct _IsCastable<T> {
+    static constexpr bool value = true;
+    using Type = T;
+};
+
+template <typename T, typename U> struct _IsCastable<T, U> {
+    using __TRUE = char;
+    using __FALSE = struct {
+        char _[2];
+    };
+    static consteval __TRUE __TEST(U);
+    static consteval __FALSE __TEST(...);
+    static constexpr bool value =
+        sizeof(__TEST(std::declval<T>())) == sizeof(__TRUE);
+    using Type = std::conditional_t<value, U, void>;
+};
+
+template <typename T, typename... Args> struct _IsCastable<T, Args...> {
+    static constexpr bool value =
+        _IsCastable<T, typename _IsCastable<Args...>::Type>::value;
+    using Type =
+        std::conditional_t<value, typename _IsCastable<Args...>::Type, void>;
+};
+
+template <typename T>
+concept _SupportString = requires {
+    _IsCastable<T, const char *, char *, std::string, std::string_view>::value;
+};
+
+template <_SupportString T> std::string _to_string(T &&str) {
+    if constexpr (std::is_same_v<std::decay_t<T>, std::string>) {
+        return str;
+    } else if constexpr (std::is_same_v<std::decay_t<T>, std::string_view>) {
+        return std::move(std::string(str.data()));
+    } else if constexpr (std::is_same_v<std::decay_t<T>,  const char*>) {
+        return std::string(str);
+    }
+}
 
 static std::vector<std::string> GetUsbPorts() {
     std::vector<std::string> portArray;
@@ -43,12 +101,6 @@ static std::vector<std::string> GetUsbPorts() {
     return portArray;
 }
 
-template <typename T>
-concept SupportString = requires {
-    std::is_same_v<T, const char *>;
-    std::is_same_v<T, std::string>;
-};
-
 enum class [[maybe_unused]] SerialErrorCode {
     SUCCESS,
     TIMEOUT,
@@ -73,6 +125,8 @@ class Serial {
     Serial &operator=(Serial &&other) = delete;
 
     auto SetRemoveEcho(bool remove) { removeEcho = remove; }
+    auto SetDtr(bool flag) { return flag ? ser.setDTR() : ser.clearDTR(); }
+    auto SetRts(bool flag) { return flag ? ser.setRTS() : ser.clearRTS(); }
 
     static std::string GetTimeNow() {
         auto now = std::chrono::system_clock::now();
@@ -84,7 +138,7 @@ class Serial {
 
     bool IsOpen() { return ser.isDeviceOpen(); }
 
-    template <SupportString T>
+    template <_SupportString T>
     bool OpenDevice(T portName, unsigned int bauds = 115200,
                     int delayTime = 0) {
         std::string reallyPortName;
@@ -118,7 +172,7 @@ class Serial {
         ser.closeDevice();
     }
 
-    template <SupportString T>
+    template <_SupportString T>
     std::expected<std::string, SerialErrorCode>
     DelayGetResponse(int delayTime, T command, int timeout = 50) {
         std::this_thread::sleep_for(std::chrono::milliseconds(delayTime));
@@ -126,7 +180,7 @@ class Serial {
     }
 
     template <int repeatTime = 5, int delayTime = 200, int timeout = 200,
-              SupportString T, SupportString... Args>
+              _SupportString T, _SupportString... Args>
     bool GetAtUntilRepeat(T command, Args... args) {
         std::stringstream ss;
         int i = 0;
@@ -141,16 +195,11 @@ class Serial {
         return false;
     }
 
-    template <SupportString T>
+    template <_SupportString T>
     std::expected<std::string, SerialErrorCode>
     GetAtResponse(T command, int timeout = 50) {
         ser.flushReceiver();
-        std::string reallyCommand;
-        if constexpr (std::is_same_v<T, std::string>) {
-            reallyCommand = command + endChar;
-        } else {
-            reallyCommand = std::string(command) + endChar;
-        }
+        std::string reallyCommand = std::string(command) + endChar;
         ser.writeString(reallyCommand.c_str());
         Log("Send: " + reallyCommand);
         std::this_thread::sleep_for(10ms);
@@ -161,7 +210,7 @@ class Serial {
 
         if (size > 0) {
             buffer[size] = '\0';
-            std::string response = std::string(buffer);
+            std::string response = std::string(buffer.get());
             Log("Receive: " + response);
             if (removeEcho)
                 response.replace(0, reallyCommand.length(), "");
@@ -170,7 +219,7 @@ class Serial {
         return std::unexpected(SerialErrorCode::TIMEOUT);
     }
 
-    template <SupportString T>
+    template <_SupportString T>
     auto GetAtResponseRepeat(T command, int timeout = 200, int repeatTime = 1)
         -> void {
         for (int i = 0; i <= repeatTime; i++) {
@@ -178,17 +227,12 @@ class Serial {
         }
     }
 
-    template <int timeout = 200, SupportString T, SupportString... Args>
+    template <int timeout = 200, _SupportString T, _SupportString... Args>
     bool GetAtUntil(T command, Args... expect) {
         auto endTime = std::chrono::system_clock::now() +
                        std::chrono::milliseconds(timeout);
         ser.flushReceiver();
-        std::string reallyCommand;
-        if constexpr (std::is_same_v<T, std::string>) {
-            reallyCommand = command + endChar;
-        } else {
-            reallyCommand = std::string(command) + endChar;
-        }
+        std::string reallyCommand = std::string(command) + endChar;
         ser.writeString(reallyCommand.c_str());
         Log("Send : " + reallyCommand);
         while (std::chrono::system_clock::now() < endTime) {
diff --git a/main.cc b/main.cc
index c4d967b..1e3babb 100644
--- a/main.cc
+++ b/main.cc
@@ -1,19 +1,40 @@
+#include "include/serial.h"
 #include <algorithm>
 #include <chrono>
+#include <cstdio>
 #include <iostream>
-#include <ranges>
 #include <limits>
+#include <ranges>
 #include <string_view>
-
-#include "include/serial.h"
 #undef max
 using namespace std::literals::chrono_literals;
+using namespace std::literals::string_view_literals;
+using namespace std::literals::string_literals;
 using namespace serial;
 namespace ranges = std::ranges;
 namespace views = std::views;
 
 void PrintLog(const std::string &msg) { std::cout << msg << std::endl; }
 
+template <typename T>
+    requires std::is_same_v<T, std::string> ||
+             std::is_same_v<T, std::string_view>
+std::vector<T> split(T str, T d) {
+    auto v = views::split(str, d) | views::transform([](auto word) {
+                 return T(word.begin(), word.end());
+             });
+    return std::vector<T>(v.begin(), v.end());
+}
+
+int main() {
+    Serial ser;
+    ser.OpenDevice("COM11", 115200);
+    ser.SetLogCallBack(PrintLog);
+    ser.GetAtUntilRepeat<5>("AT", "OK");
+    return 0;
+}
+
+/*
 int main(int argc, char **const argv) {
     Serial serial;
     auto ports = serial::GetUsbPorts();
@@ -30,20 +51,20 @@ int main(int argc, char **const argv) {
         std::getline(std::cin, command);
         system("cls");
         auto startTime = std::chrono::system_clock::now();
-        if (command.find(":") != std::string::npos) {
-            command.erase(std::remove_if(command.begin(), command.end(),
-                                         [](char c) { return c == ':'; }),
-                          command.end());
-            auto reallyCommand = command.substr(0, command.find_first_of(' '));
-            auto expect = command.substr(command.find_first_of(' ') + 1,
-                                         command.length());
-            auto res = serial.GetAtUntil(reallyCommand, expect, 2000);
+        if (command.at(0) == ':') {
+            command = command.substr(1, command.length() - 1);
+            auto sp = split(command, " "s);
+            auto reallyCommand = sp[0];
+            auto expect = sp[1];
+            auto res = serial.GetAtUntil(reallyCommand, 2000, expect);
             auto endTime = std::chrono::system_clock::now();
-            std::cout << "dura: "
+            res ? std::cout
+                      << "dura: "
                       << std::chrono::duration_cast<std::chrono::milliseconds>(
                              endTime - startTime)
                              .count()
-                      << std::endl;
+                      << std::endl
+                : std::cout << "Recive Error";
         } else {
             auto resp = serial.GetAtResponse(command);
             auto endTime = std::chrono::system_clock::now();
@@ -57,3 +78,4 @@ int main(int argc, char **const argv) {
     }
     return 0;
 }
+*/
\ No newline at end of file