文章目录
- 一·、HC-SR04模块介绍
- 二、创建工程
- 1.选择芯片
- 2.配置RCC、SY![在这里插入图片描述](https://img-blog.csdnimg.cn/direct/9d2a5b883f0e409eabb804e6da861277.png)
- 3.配置串口1
- 4.配置定时器
- 5.配置GPIO
- 三、Keil代码
- 1.勾选Use MicroLIB
- 2.创建SR04.c和SR04.h文件
- 3.其他代码
- 四、效果
- 五、参考资料:
一·、HC-SR04模块介绍
超声波是振动频率高于20kHz的机械波。它具有频率高、波长短、绕射现象小、方向性好、能够成为射线而定向传播等特点。HC-SRO4是一款尺寸完全兼容老版本,增加UART和IIC功能的开放式超声波测距模块,默认条件下,软件与硬件完全兼容老版本HC-SRO4;可以通过电阻设置成UART或IIC模式。2CM盲区,4.5M典型最远测距,2.2mA作电流。采用升级解调芯片RCWL-9206,带UART与IIC功能MCU:使其外围更加简洁,工作电压更宽(3-5.5V),接口功能更多。
- 模块参数:
①专业解调测距芯片RCWL-9206
②支持GPIO,UART与IIC三种模式接口
③2.2mA工作电流
④2cm最小盲区
⑤2cm-450cm的超宽测量范围
⑥工作温度:-10°C-70°c
⑦3V-5.5V宽电压供电
注:0~40℃声速误差7%左右,实际应用时需要考虑温度影响
-
实验步骤
1.配置GPIO引脚结构体(Trig,Echo)
2.配置定时器结构体
3.配置定时器中断结构体
4.开启时钟(定时器、GPIO)
5.Trig引脚输出高电平(10us以上),然后关闭
6.等待Echo引脚输出高电平开始,定时器打开->开启计数器计数
7.等待Echo引脚输出高电平结束,定时器关闭->停止计数器计数
二、创建工程
1.选择芯片
打开STM32CubuMax,新建一个项目,选择芯片
2.配置RCC、SY
S、时钟树
rcc
sys
时钟树
3.配置串口1
4.配置定时器
5.配置GPIO
完成后生成keil工程
三、Keil代码
1.勾选Use MicroLIB
2.创建SR04.c和SR04.h文件
SR04.c
#include "SR04.h"
float distant; //测量距离
uint32_t measure_Buf[3] = {0}; //存放定时器计数值的数组
uint8_t measure_Cnt = 0; //状态标志位
uint32_t high_time; //超声波模块返回的高电平时间
//===============================================读取距离
void SR04_GetData(void)
{
switch (measure_Cnt){
case 0:
TRIG_H;
delay_us(30);
TRIG_L;
measure_Cnt++;
__HAL_TIM_SET_CAPTUREPOLARITY(&htim2, TIM_CHANNEL_1, TIM_INPUTCHANNELPOLARITY_RISING);
HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_1); //启动输入捕获 或者: __HAL_TIM_ENABLE(&htim5);
break;
case 3:
high_time = measure_Buf[1]- measure_Buf[0]; //高电平时间
printf("\r\n----高电平时间-%d-us----\r\n",high_time);
distant=(high_time*0.034)/2; //单位cm
printf("\r\n-检测距离为-%.2f-cm-\r\n",distant);
measure_Cnt = 0; //清空标志位
TIM2->CNT=0; //清空计时器计数
break;
}
}
//===============================================us延时函数
void delay_us(uint32_t us)//主频72M
{
uint32_t delay = (HAL_RCC_GetHCLKFreq() / 4000000 * us);
while (delay--)
{
;
}
}
//===============================================中断回调函数
void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)//
{
if(TIM2 == htim->Instance)// 判断触发的中断的定时器为TIM2
{
switch(measure_Cnt){
case 1:
measure_Buf[0] = HAL_TIM_ReadCapturedValue(&htim2,TIM_CHANNEL_1);//获取当前的捕获值.
__HAL_TIM_SET_CAPTUREPOLARITY(&htim2,TIM_CHANNEL_1,TIM_ICPOLARITY_FALLING); //设置为下降沿捕获
measure_Cnt++;
break;
case 2:
measure_Buf[1] = HAL_TIM_ReadCapturedValue(&htim2,TIM_CHANNEL_1);//获取当前的捕获值.
HAL_TIM_IC_Stop_IT(&htim2,TIM_CHANNEL_1); //停止捕获 或者: __HAL_TIM_DISABLE(&htim5);
measure_Cnt++;
}
}
}
SR04.h
#ifndef __SR04_H
#define __SR04_H
#include "main.h"
#include "tim.h"
#include "stdio.h"
#define TRIG_H HAL_GPIO_WritePin(Trig_GPIO_Port,Trig_Pin,GPIO_PIN_SET)
#define TRIG_L HAL_GPIO_WritePin(Trig_GPIO_Port,Trig_Pin,GPIO_PIN_RESET)
void delay_us(uint32_t us);
void SR04_GetData(void);
#endif
添加进工程
3.其他代码
usrat.c中添加
/* USER CODE BEGIN 0 */
#include "stdio.h"
/* USER CODE END 0 */
/* USER CODE BEGIN 1 */
/*********************************************************
*
*重定义 fputc 函数
*
*********************************************************/
int fputc(int ch,FILE *f)
{
HAL_UART_Transmit (&huart1 ,(uint8_t *)&ch,1,HAL_MAX_DELAY );
return ch;
}
/* USER CODE END 1 */
main函数
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* <h2><center>© Copyright (c) 2022 STMicroelectronics.
* All rights reserved.</center></h2>
*
* This software component is licensed by ST under BSD 3-Clause license,
* the "License"; You may not use this file except in compliance with the
* License. You may obtain a copy of the License at:
* opensource.org/licenses/BSD-3-Clause
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "tim.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "SR04.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_TIM2_Init();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
SR04_GetData( );
HAL_Delay(300);
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
四、效果
HC-SR04模块接线
VCC接5V
GND接地
TRIG接A1
ECHO接A0
五、参考资料:
[1]https://blog.csdn.net/qq_52215423/article/details/131034232?ops_request_misc=&request_id=&biz_id=102&utm_term=stm32%E8%B6%85%E5%A3%B0%E6%B3%A2%E6%B5%8B%E8%B7%9D&utm_medium=distribute.pc_search_result.none-task-blog-2allsobaiduweb~default-1-131034232.142
[2]https://blog.csdn.net/lwb450921/article/details/123670786?spm=1001.2014.3001.5502
[3]https://blog.csdn.net/weixin_72921448/article/details/127586521?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522171721873616800186519673%2522%252C%2522scm%2522%253A%252220140713.130102334…%2522%257D&request_id=171721873616800186519673&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2alltop_click~default-4-127586521-null-null.142