diff --git a/Core/Inc/syscalls.h b/Core/Inc/syscalls.h
index 81c09c0..5327636 100644
--- a/Core/Inc/syscalls.h
+++ b/Core/Inc/syscalls.h
@@ -3,11 +3,15 @@
 
 #include <errno.h>
 #include <signal.h>
+#include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stm32f1xx_hal_uart.h>
 #include <time.h>
 
+#define HUART1 (&huart1)
+#define HUART2 (&huart2)
+
 extern UART_HandleTypeDef huart2;
 
 extern int __io_putchar(int ch) __attribute__((weak));
@@ -76,4 +80,23 @@ void delay_us(uint16_t us) {
     uint32_t delay = (HAL_RCC_GetHCLKFreq() / 4000000 * us);
     while (delay--);
 }
+
+/**
+ * @brief 自定义printf
+ * @param huart, buf
+ * @return void
+ *
+ * @usage my_printf(HUART1, "USART1_Target:\r\n");
+ */
+void my_printf(UART_HandleTypeDef *huart, const char *buf, ...) {
+    const char *p = buf;
+    char str[255] = {0};
+    va_list v;
+    va_start(v, buf);
+    vsprintf(str, buf, v);
+    HAL_UART_Transmit(huart, str, strlen(str), 0xff);
+    va_end(v);
+}
+
+
 #endif