如下图所示,最便宜的舵机sg90,常用三根或者四根接线,黄色为PWM信号控制
用处:垃圾桶项目开盖用、智能小车的全比例转向、摄像头云台、机械臂等
常见的有0-90°、0-180°、0-360°
黄线:提供pwm信号,主要看芯片提供的信号源。
文章:嵌入式-stm32-用PWM点亮LED实现呼吸灯
了解什么是PWM?占空比?上面的文章有必要读,如果你是小白
答:PWM是脉宽调制(Pulse Width Modulation)的缩写,是一种用来控制电子设备的技术。在PWM中,周期固定,但信号的高电平时间(脉冲宽度)可以调整,从而改变信号的平均功率或电压。
占空比(Duty Cycle)是指在一个周期内,信号的高电平时间与周期的比例。通常以百分比表示,如50%表示高电平时间占周期的一半。
通过改变PWM信号的占空比,可以实现对电子设备的精确控制。例如,用于调光的LED灯就是通过改变PWM信号的占空比来控制亮度的。较高的占空比意味着更长的高电平时间,产生更高的平均功率或电压,而较低的占空比则相反。
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
①找LED灯是哪个引脚控制,这里选PB9
这里加LED目的是为了更直观看到代码烧录成功,加了一个PB9控制LED2,当代码烧录成功,LED2亮,借此观察舵机情况。
②舵机信号由PB8传输
1.6、学会看产品手册
由STM32F103xx产品手册可以知道引脚PB8是由定时器TIM4的第三个通道3决定的.
这是强大的hal库帮我们封装好的,我们会调用就行了
温馨提示:STM近年来主推且不断更新HAI库和LL库,反而标准库已经好几年不更新了,这样子用stm板子开发速度很快,就是换国产芯片做产品时还是得用标准库,
Debug模式选择调试需求,
Serial Wire模式:适合于使用串行线调试器(ST-LINK、J-link等)进行单步调试以及运行时跟踪情况
复位和时钟控制
这里是选做功能,用来检验代码烧录成功之后LED亮,可在main.c主函数中添加以下代码:
while(1)
/* USER CODE END YHILE */
HAL_GPIO_WritePin(GPIOB,GPIO_PIN_9,GPIO_PIN_RESET);
HAL_Delay(1000);
HAL_GPIO_WritePin(GPIOB,GPIO_PIN_9,GPIO_PIN_SET);
HAL_Delay(1000);
/* USER CODE BEGIN 3 */
配置时钟频率
记得把极性设置为Low,因为LED灯是低电平才亮。
项目名称:sg90_study
①开启定时器
/* USER CODE BEGIN 2 */
HAL_TIM_PWM_Start(&htim4,TIM_CHANNEL_3);//打开pwm要在初始化之后打开
/* USER CODE END 2 */
②在while(1)循环中添加业务逻辑代码
{
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);
}
/* 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"
#include "tim.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* 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_TIM4_Init();
/* USER CODE BEGIN 2 */
HAL_TIM_PWM_Start(&htim4,TIM_CHANNEL_3);//打开pwm要在初始化之后打开
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
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);
/* 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 */
3.3、sg90舵机效果
1.代码编译,烧录之后
sg90舵机的运动情况
每隔1s,转动一个角度:0度 --> 45度 --> 90度 --> 135度 --> 180度 --> 0度
以上,完