diff --git a/README.md b/README.md
index 804c0bb..8df8bc6 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@
         ssh-copy-id iflytop@板子IP
 
 编译:
-        ./build.sh
+        ./sh/build.sh
 
 部署:
         ./sh/deploy.sh username ip
diff --git a/demo/uart/test_uart232_1.cpp b/demo/uart/test_uart232_1.cpp
index cdec78c..9526034 100644
--- a/demo/uart/test_uart232_1.cpp
+++ b/demo/uart/test_uart232_1.cpp
@@ -21,7 +21,13 @@ using namespace iflytop;
 
 int main(int argc, char const* argv[]) {
   Uart uart;
-  uart.open(UART_NAME, "115200");
+  int  ret = uart.open(UART_NAME, "115200");
+  if (ret != 0) {
+    perror("open uart error");
+    exit(1);
+
+  }
+
 
   thread th([&]() {
     //
diff --git a/demo/uart/test_uart232_2.cpp b/demo/uart/test_uart232_2.cpp
index 9edf997..9893684 100644
--- a/demo/uart/test_uart232_2.cpp
+++ b/demo/uart/test_uart232_2.cpp
@@ -21,7 +21,13 @@ using namespace iflytop;
 
 int main(int argc, char const* argv[]) {
   Uart uart;
-  uart.open(UART_NAME, "115200");
+  int  ret = uart.open(UART_NAME, "115200");
+  if (ret != 0) {
+    perror("open uart error");
+    exit(1);
+
+  }
+
 
   thread th([&]() {
     //
diff --git a/demo/uart/test_uart485.cpp b/demo/uart/test_uart485.cpp
index c693f69..bf24d69 100644
--- a/demo/uart/test_uart485.cpp
+++ b/demo/uart/test_uart485.cpp
@@ -21,7 +21,12 @@ using namespace iflytop;
 
 int main(int argc, char const* argv[]) {
   Uart uart;
-  uart.open(UART_NAME, "115200");
+  int  ret = uart.open(UART_NAME, "115200");
+  if (ret != 0) {
+    perror("open uart error");
+    exit(1);
+
+  }
 
   thread th([&]() {
     //
diff --git a/demo/uart/test_usbuart.cpp b/demo/uart/test_usbuart.cpp
index 5e1a6ff..65b99a2 100644
--- a/demo/uart/test_usbuart.cpp
+++ b/demo/uart/test_usbuart.cpp
@@ -21,7 +21,12 @@ using namespace iflytop;
 
 int main(int argc, char const* argv[]) {
   Uart uart;
-  uart.open(UART_NAME, "115200");
+  int  ret = uart.open(UART_NAME, "115200");
+  if (ret != 0) {
+    perror("open uart error");
+    exit(1);
+  }
+
 
   thread th([&]() {
     //