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目录
项目需求
项目框图
编辑
硬件清单
sg90舵机介绍及实战
sg90舵机介绍
角度控制
SG90舵机编程实现
超声波传感器介绍及实战
超声波传感器介绍
超声波编程实战
项目设计及实现
项目需求
- 检测靠近时,垃圾桶自动开盖并伴随滴一声,2秒后关盖
- 发生震动时,垃圾桶自动开盖并伴随滴一声,2秒后关盖
- 按下按键时,垃圾桶自动开盖并伴随滴一声,2秒后关盖
项目框图
硬件清单
SG90舵机,超声波模块,震动传感器,蜂鸣器
sg90舵机介绍及实战
sg90舵机介绍
PWM波的频率不能太高,大约50HZ,即周期=1/频率=1/50=0.02s,20ms左右。
确定周期/频率
如果周期为20ms,则 PSC=7199,ARR=199
角度控制
- 0.5ms-------------0度; 2.5% 对应函数中CCRx为5
- 1.0ms------------45度; 5.0% 对应函数中CCRx为10
- 1.5ms------------90度; 7.5% 对应函数中CCRx为15
- 2.0ms-----------135度; 10.0% 对应函数中CCRx为20
- 2.5ms-----------180度; 12.5% 对应函数中CCRx为25
SG90舵机编程实现
需求:
每隔1s,转动一个角度:0度 --> 45度 --> 90度 --> 135度 --> 180度 --> 0度
接线:

HAL_TIM_PWM_Start(&htim4,TIM_CHANNEL_3);
while (1)
{HAL_Delay(1000);__HAL_TIM_SetCompare(&htim4, TIM_CHANNEL_3, 5);HAL_Delay(1000);__HAL_TIM_SetCompare(&htim4, TIM_CHANNEL_3, 10);HAL_Delay(1000);__HAL_TIM_SetCompare(&htim4, TIM_CHANNEL_3, 15);HAL_Delay(1000);__HAL_TIM_SetCompare(&htim4, TIM_CHANNEL_3, 20);HAL_Delay(1000);__HAL_TIM_SetCompare(&htim4, TIM_CHANNEL_3, 25);
}
超声波传感器介绍及实战
超声波传感器介绍
- 怎么让它发送波
Trig ,给Trig端口至少10us的高电平
- 怎么知道它开始发了
Echo信号,由低电平跳转到高电平,表示开始发送波
- 怎么知道接收了返回波
Echo,由高电平跳转回低电平,表示波回来了
- 怎么算时间
Echo引脚维持高电平的时间!
- 波发出去的那一下,开始启动定时器
波回来的拿一下,我们开始停止定时器,计算出中间经过多少时间
- 怎么算距离
距离 = 速度 (340m/s)* 时间/2
超声波编程实战
需求:
使用超声波测距,当手离传感器距离小于5cm时,LED1点亮,否则保持不亮状态。
接线:
Trig --- PB6
Echo --- PB7
LED1 --- PB8

定时器配置:
使用 TIM2 ,只用作计数功能,不用作定时。
将 PSC 配置为71,则计数 1 次代表 1us 。

编写微秒级函数:
//使用TIM2来做us级延时函数
void TIM2_Delay_us(uint16_t n_us)
{/* 使能定时器2计数 */__HAL_TIM_ENABLE(&htim2);__HAL_TIM_SetCounter(&htim2, 0);while(__HAL_TIM_GetCounter(&htim2) < ((1 * n_us)-1) );/* 关闭定时器2计数 */__HAL_TIM_DISABLE(&htim2);
}
主函数:
//1. Trig ,给Trig端口至少10us的高电平 //2. echo由低电平跳转到高电平,表示开始发送波 //波
发出去的那一下,开始启动定时器 //3. 由高电平跳转回低电平,表示波回来了 //波回来的那一
下,我们开始停止定时器 //4. 计算出中间经过多少时间 //5. 距离 = 速度 (340m/s)* 时间/2
(计数1次表示1us) //每500毫秒测试一次距离
int cnt;
float distance;
while (1)
{//1. Trig ,给Trig端口至少10us的高电平HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_SET);//拉高TIM2_Delay_us(20);HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_RESET);//拉低//2. echo由低电平跳转到高电平,表示开始发送波//波发出去的那一下,开始启动定时器while(HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_7) == GPIO_PIN_RESET);//等待输入电平拉高HAL_TIM_Base_Start(&htim2);__HAL_TIM_SetCounter(&htim2,0);//3. 由高电平跳转回低电平,表示波回来了while(HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_7) == GPIO_PIN_SET);//等待输入电平变低//波回来的那一下,我们开始停止定时器HAL_TIM_Base_Stop(&htim2);//4. 计算出中间经过多少时间cnt = __HAL_TIM_GetCounter(&htim2);//5. 距离 = 速度 (340m/s)* 时间/2(计数1次表示1us)distance = cnt*340/2*0.000001*100; //单位:cmif(distance < 5)HAL_GPIO_WritePin(GPIOB, GPIO_PIN_8, GPIO_PIN_RESET);elseHAL_GPIO_WritePin(GPIOB, GPIO_PIN_8, GPIO_PIN_SET);//每500毫秒测试一次距离HAL_Delay(500);
}
项目设计及实现
项目设计
超声波模块:
Trig -- PB6
Echo -- PB7
sg90舵机:PWM -- PB9
按键:
KEY1 -- PA0
LED灯:
LED1 -- PB8
震动传感器:
D0 -- PB5
VCC -- 5V
蜂鸣器:
IO -- PB4
VCC -- 3V3
/* USER CODE BEGIN Header */
/********************************************************************************* @file : main.c* @brief : Main program body******************************************************************************* @attention** Copyright (c) 2023 STMicroelectronics.* All rights reserved.** This software is licensed under terms that can be found in the LICENSE file* in the root directory of this software component.* If no LICENSE file comes with this software, it is provided AS-IS.********************************************************************************/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes *//* USER CODE END Includes *//* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
#define OPEN 1
#define CLOSE 0
/* USER CODE END PTD *//* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD *//* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
char flag=CLOSE;
/* USER CODE END PM *//* Private variables ---------------------------------------------------------*/
TIM_HandleTypeDef htim2;
TIM_HandleTypeDef htim4;/* USER CODE BEGIN PV *//* USER CODE END PV *//* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_TIM2_Init(void);
static void MX_TIM4_Init(void);
/* USER CODE BEGIN PFP *//* USER CODE END PFP *//* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 *///使用TIM2来做us级延时函数
void TIM2_Delay_us(uint16_t n_us)
{
/* 使能定时器2计数 */
__HAL_TIM_ENABLE(&htim2);
__HAL_TIM_SetCounter(&htim2, 0);
while(__HAL_TIM_GetCounter(&htim2) < ((1 * n_us)-1) );
/* 关闭定时器2计数 */
__HAL_TIM_DISABLE(&htim2);
}
double get_distance()
{int cnt;//1. Trig ,给Trig端口至少10us的高电平HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_SET);//拉高TIM2_Delay_us(20);HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_RESET);//拉低//2. echo由低电平跳转到高电平,表示开始发送波//波发出去的那一下,开始启动定时器while(HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_7) == GPIO_PIN_RESET);//等待输入电平拉高HAL_TIM_Base_Start(&htim2);__HAL_TIM_SetCounter(&htim2,0);//3. 由高电平跳转回低电平,表示波回来了while(HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_7) == GPIO_PIN_SET);//等待输入电平变低//波回来的那一下,我们开始停止定时器HAL_TIM_Base_Stop(&htim2);//4. 计算出中间经过多少时间cnt = __HAL_TIM_GetCounter(&htim2);//5. 距离 = 速度 (340m/s)* 时间/2(计数1次表示1us)return (cnt*340/2*0.000001*100); //单位:cm
}
void openStatusLight()
{HAL_GPIO_WritePin(GPIOB, GPIO_PIN_8, GPIO_PIN_RESET);
}
void closeStatusLight()
{HAL_GPIO_WritePin(GPIOB, GPIO_PIN_8, GPIO_PIN_SET);
}
void initSG90_0()
{HAL_TIM_PWM_Start(&htim4,TIM_CHANNEL_4);//启动定时器4__HAL_TIM_SetCompare(&htim4, TIM_CHANNEL_4, 5);//将舵机置0°
}
void openDusbin()
{if(flag==CLOSE){flag=OPEN;__HAL_TIM_SetCompare(&htim4, TIM_CHANNEL_4, 15);//将舵机置90°HAL_GPIO_WritePin(GPIOB,GPIO_PIN_4,GPIO_PIN_RESET);HAL_Delay(100);HAL_GPIO_WritePin(GPIOB,GPIO_PIN_4,GPIO_PIN_SET);}HAL_Delay(2000);
}void closeDusbin()
{__HAL_TIM_SetCompare(&htim4, TIM_CHANNEL_4, 5);//将舵机置0°flag=CLOSE;HAL_Delay(150);
}void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{if(GPIO_Pin==GPIO_PIN_0||GPIO_Pin==GPIO_PIN_5){if(HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0)==GPIO_PIN_RESET ||HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_5)==GPIO_PIN_RESET){openStatusLight();openDusbin();}}}/* USER CODE END 0 *//*** @brief The application entry point.* @retval int*/
int main(void)
{/* USER CODE BEGIN 1 */float distance;/* 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_TIM4_Init();/* USER CODE BEGIN 2 */initSG90_0();HAL_NVIC_SetPriority(SysTick_IRQn,0,0);/* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */while (1){/* USER CODE END WHILE *//* USER CODE BEGIN 3 *///超声波测距distance=get_distance();if(distance < 10){openStatusLight();//开盖openDusbin();}else{closeStatusLight();//关盖closeDusbin();}}/* 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();}
}/*** @brief TIM2 Initialization Function* @param None* @retval None*/
static void MX_TIM2_Init(void)
{/* USER CODE BEGIN TIM2_Init 0 *//* USER CODE END TIM2_Init 0 */TIM_ClockConfigTypeDef sClockSourceConfig = {0};TIM_MasterConfigTypeDef sMasterConfig = {0};/* USER CODE BEGIN TIM2_Init 1 *//* USER CODE END TIM2_Init 1 */htim2.Instance = TIM2;htim2.Init.Prescaler = 71;htim2.Init.CounterMode = TIM_COUNTERMODE_UP;htim2.Init.Period = 65535;htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;if (HAL_TIM_Base_Init(&htim2) != HAL_OK){Error_Handler();}sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK){Error_Handler();}sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK){Error_Handler();}/* USER CODE BEGIN TIM2_Init 2 *//* USER CODE END TIM2_Init 2 */}/*** @brief TIM4 Initialization Function* @param None* @retval None*/
static void MX_TIM4_Init(void)
{/* USER CODE BEGIN TIM4_Init 0 *//* USER CODE END TIM4_Init 0 */TIM_ClockConfigTypeDef sClockSourceConfig = {0};TIM_MasterConfigTypeDef sMasterConfig = {0};TIM_OC_InitTypeDef sConfigOC = {0};/* USER CODE BEGIN TIM4_Init 1 *//* USER CODE END TIM4_Init 1 */htim4.Instance = TIM4;htim4.Init.Prescaler = 7199;htim4.Init.CounterMode = TIM_COUNTERMODE_UP;htim4.Init.Period = 199;htim4.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;htim4.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;if (HAL_TIM_Base_Init(&htim4) != HAL_OK){Error_Handler();}sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;if (HAL_TIM_ConfigClockSource(&htim4, &sClockSourceConfig) != HAL_OK){Error_Handler();}if (HAL_TIM_PWM_Init(&htim4) != HAL_OK){Error_Handler();}sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;if (HAL_TIMEx_MasterConfigSynchronization(&htim4, &sMasterConfig) != HAL_OK){Error_Handler();}sConfigOC.OCMode = TIM_OCMODE_PWM1;sConfigOC.Pulse = 0;sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;if (HAL_TIM_PWM_ConfigChannel(&htim4, &sConfigOC, TIM_CHANNEL_4) != HAL_OK){Error_Handler();}/* USER CODE BEGIN TIM4_Init 2 *//* USER CODE END TIM4_Init 2 */HAL_TIM_MspPostInit(&htim4);}/*** @brief GPIO Initialization Function* @param None* @retval None*/
static void MX_GPIO_Init(void)
{GPIO_InitTypeDef GPIO_InitStruct = {0};/* GPIO Ports Clock Enable */__HAL_RCC_GPIOD_CLK_ENABLE();__HAL_RCC_GPIOA_CLK_ENABLE();__HAL_RCC_GPIOB_CLK_ENABLE();/*Configure GPIO pin Output Level */HAL_GPIO_WritePin(GPIOB, GPIO_PIN_4|GPIO_PIN_8, GPIO_PIN_SET);/*Configure GPIO pin Output Level */HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_RESET);/*Configure GPIO pin : PA0 */GPIO_InitStruct.Pin = GPIO_PIN_0;GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;GPIO_InitStruct.Pull = GPIO_NOPULL;HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);/*Configure GPIO pins : PB4 PB6 PB8 */GPIO_InitStruct.Pin = GPIO_PIN_4|GPIO_PIN_6|GPIO_PIN_8;GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;GPIO_InitStruct.Pull = GPIO_NOPULL;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);/*Configure GPIO pin : PB5 */GPIO_InitStruct.Pin = GPIO_PIN_5;GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;GPIO_InitStruct.Pull = GPIO_NOPULL;HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);/*Configure GPIO pin : PB7 */GPIO_InitStruct.Pin = GPIO_PIN_7;GPIO_InitStruct.Mode = GPIO_MODE_INPUT;GPIO_InitStruct.Pull = GPIO_NOPULL;HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);/* EXTI interrupt init*/HAL_NVIC_SetPriority(EXTI0_IRQn, 2, 0);HAL_NVIC_EnableIRQ(EXTI0_IRQn);HAL_NVIC_SetPriority(EXTI9_5_IRQn, 2, 0);HAL_NVIC_EnableIRQ(EXTI9_5_IRQn);}/* 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 */