实现串口驱动，移植方便

HAL/Src/hal_delay.c

@@ -0,0 +1,43 @@
+/* USER CODE BEGIN Header */
+/**
+  ******************************************************************************
+  * @file           : hal_delay.c
+  * @brief          : Delay hardware abstraction layer source file
+  ******************************************************************************
+  */
+/* USER CODE END Header */
+
+#include "hal_delay.h"
+#include "stm32f4xx_hal.h"
+
+/**
+ * @brief Initialize delay module
+ */
+void hal_delay_init(void) {
+    /* Delay initialization is handled by HAL_Init() */
+}
+
+/**
+ * @brief Delay in milliseconds
+ * @param ms: Delay time in milliseconds
+ */
+void hal_delay_ms(uint32_t ms) {
+    HAL_Delay(ms);
+}
+
+/**
+ * @brief Delay in microseconds
+ * @param us: Delay time in microseconds
+ */
+void hal_delay_us(uint32_t us) {
+    uint32_t ticks = 0;
+    uint32_t start_tick = 0;
+    uint32_t tick_freq = HAL_RCC_GetHCLKFreq() / 1000000;
+    
+    ticks = us * tick_freq;
+    start_tick = HAL_GetTick() * tick_freq;
+    
+    while ((HAL_GetTick() * tick_freq - start_tick) < ticks) {
+        /* Busy wait */
+    }
+}