修改delay_us实现以及相关的超声波实现

Core/Inc/syscalls.h

@@ -0,0 +1,79 @@
+#ifndef __SYSCALLS_H
+#define __SYSCALLS_H
+
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stm32f1xx_hal_uart.h>
+#include <time.h>
+
+extern UART_HandleTypeDef huart2;
+
+extern int __io_putchar(int ch) __attribute__((weak));
+extern int __io_getchar(void) __attribute__((weak));
+
+__attribute__((weak)) int _read(int file, char *ptr, int len) {
+    (void)file;
+    int DataIdx;
+
+    for (DataIdx = 0; DataIdx < len; DataIdx++) {
+        *ptr++ = __io_getchar();
+    }
+
+    return len;
+}
+
+__attribute__((weak)) int _write(int file, char *ptr, int len) {
+    (void)file;
+    int DataIdx;
+
+    for (DataIdx = 0; DataIdx < len; DataIdx++) {
+        __io_putchar(*ptr++);
+    }
+    return len;
+}
+
+// 条件编译
+#ifdef __GNUC__
+#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
+#define GETCHAR_PROTOTYPE int __io_getchar(void)
+#else
+#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
+#define GETCHAR_PROTOTYPE int fgetc(FILE *f)
+#endif /* __GNUC__ */
+
+/**
+ * @brief 重定向 C 标准库 printf 函数到串口 huart2
+ * @author Suroy
+ * @param ch
+ * @param f
+ * @return int
+ *
+ * @usage printf("USART1_Target:\r\n");
+ */
+PUTCHAR_PROTOTYPE {
+    HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, HAL_MAX_DELAY); // 阻塞式无限等待
+    return ch;
+}
+
+/**
+ * @brief 重定向 c库函数 getchar,scanf到 DEBUG_USARTx
+ * 重定向 C 标准库 scanf 函数到串口 huart2
+ * 注意以 空格 为结束
+ * @param f
+ * @return int
+ *
+ * @usage scanf("%c", &RecData);
+ */
+GETCHAR_PROTOTYPE {
+    uint8_t ch = 0;
+    HAL_UART_Receive(&huart2, (uint8_t *)&ch, 1, HAL_MAX_DELAY);
+    return ch;
+}
+
+void delay_us(uint16_t us) {
+    uint32_t delay = (HAL_RCC_GetHCLKFreq() / 4000000 * us);
+    while (delay--);
+}
+#endif

Core/Src/hcsr04.c

@@ -1,10 +1,8 @@
 #include "hcsr04.h"
 #include "tim.h"
-#include <stdio.h>
 
 static uint64_t time;     // 声明变量，用来计时
 static uint64_t time_end; // 声明变量，存储回波信号时间
-static int16_t delay_time = -1; // 用于延时
 uint8_t sonor_state;      // 测距状态变量，0：未测量，1：正在测量，2：已测量
 uint32_t sonor_distance;  // 测量出的距离，单位mm
 
@@ -37,28 +35,12 @@ uint32_t sonar_mm(void)
     return sonor_distance;
 }
 
-/// @brief 微秒级延时
-/// @param us 取值范围0-32767
-void delay_us(uint16_t us)
-{
-    if (us == 0)
-        return;
-    delay_time = us;
-    time = 0;
-    HAL_TIM_Base_Start_IT(&htim2);
-    while (time < us)
-        ;
-    delay_time = -1;
-}
-
 void HCSR04_HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
 {
     if (htim == &htim2)
     {
         // 每10us自增一
         ++time;
-        if (delay_us > 0 && time * 10 >= delay_time)
-            HAL_TIM_Base_Stop_IT(&htim2);
     }
 }
 

Core/Src/main.c

@@ -19,14 +19,15 @@
 /* Includes ------------------------------------------------------------------*/
 #include "main.h"
 #include "dma.h"
+#include "gpio.h"
 #include "i2c.h"
 #include "tim.h"
 #include "usart.h"
-#include "gpio.h"
 
 /* Private includes ----------------------------------------------------------*/
 /* USER CODE BEGIN Includes */
 #include <stdio.h>
+#include "syscalls.h"
 #include "bluetooth.h"
 #include "led.h"
 #include "hcsr04.h"
@@ -109,22 +110,11 @@ int main(void)
   /* USER CODE BEGIN WHILE */
   while (1)
   {
-    int Distance_mm = sonar_mm();
-    int Distance_m = Distance_mm / 1000;
-    int Distance_m_p = Distance_mm % 1000;
-    printf("Distance_mm = %d\n", Distance_mm);
-    printf("Distance_m = %d\n", Distance_m);
-    printf("Distance_m_p = %d\n", Distance_m_p);
+    printf("test\n");
 
-    if (Distance_mm < 100)
+    if (sonor_state == 0)
     {
-      LED_Start(LED_R);
-      MOTOR_Start();
-    }
-    else
-    {
-      LED_Stop(LED_R);
-      MOTOR_Stop();
+      sonar_mm();
     }
     HAL_Delay(300); // 延时300毫秒
 

Core/Src/usart.c

@@ -219,18 +219,5 @@ void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
 }
 
 /* USER CODE BEGIN 1 */
-int fputc(int c, FILE* f)
-{
-	static uint8_t ch;
-	ch = c;
-	HAL_UART_Transmit(&huart1, &ch, 1, 1000);
-	return c;
-}
 
-int fgetc(FILE* f)
-{
-	static uint8_t ch;
-	HAL_UART_Receive(&huart1, &ch, 1, 0xffff);
-	return ch;
-}
 /* USER CODE END 1 */