STM8S系列基于STVD标准库外设库开发，PWM输出实现LED呼吸灯效果

Posted 2022-12-10 perseverance52

STM8S系列基于STVD标准库外设库开发，PWM输出实现LED呼吸灯效果

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• 📌相关篇《STM8S系列基于STVD开发，标准外设库函数开发环境搭建》

🎉利用定时器5，输出比较功能，作为产生pwm来源。

🌼PWM相关库函数解析

/**
  * @brief  Initializes the TIM5 Channel1 according to the specified parameters.
  * @param   TIM5_OCMode specifies the Output Compare mode  from @ref TIM5_OCMode_TypeDef.
  * @param   TIM5_OutputState specifies the Output State  from @ref TIM5_OutputState_TypeDef.
  * @param   TIM5_Pulse specifies the Pulse width  value.
  * @param   TIM5_OCPolarity specifies the Output Compare Polarity  from @ref TIM5_OCPolarity_TypeDef.
  * @retval None
  */
void TIM5_OC1Init(TIM5_OCMode_TypeDef TIM5_OCMode,
                  TIM5_OutputState_TypeDef TIM5_OutputState,
                  uint16_t TIM5_Pulse,
                  TIM5_OCPolarity_TypeDef TIM5_OCPolarity)

TIM5_OC1Init是采用的通道1，另外还有通道2和3：TIM5_OC2Init，TIM5_OC2Init
，分别代表的是输出引脚：通道1（PD4），通道2（PD3）。通道3（PD2）

• 🌿参数一：TIM5_OCMode_TypeDef 输出比较 & PWM通道设置

/** TIM5 Output Compare and PWM modes */
typedef enum

    TIM5_OCMODE_TIMING     =((uint8_t)0x00),
    TIM5_OCMODE_ACTIVE     =((uint8_t)0x10),
    TIM5_OCMODE_INACTIVE   =((uint8_t)0x20),
    TIM5_OCMODE_TOGGLE     =((uint8_t)0x30),
    TIM5_OCMODE_PWM1       =((uint8_t)0x60),
    TIM5_OCMODE_PWM2       =((uint8_t)0x70)
TIM5_OCMode_TypeDef;

• TIM_OCMode_Timing:输出比较时间模式 (输出引脚冻结无效)
• TIM_OCMode_Active:输出比较主动模式 (匹配时设置输出引脚为有效电平，当计数值为比较/捕获寄存器值相同时，强制输出为高电平)
• TIM_OCMode_Inactive;输出比较非主动模式 (匹配时设置输出引脚为无效电平，当计数值为比较/捕获寄存器值相同时，强制输出为低电平)
• TIM_OCMode_Toggle : 输出比较触发模式 (翻转。当计数值与比较/捕获寄存器值相同时，翻转输出引脚的电平)
• TIM_OCMode_PWM1 : 向上计数时，当TIMx_CNT < TIMx_CCR时，输出电平有效，否则为无效向下计数时，当TIMx_CNT > TIMx_CCR时，输出电平无效，否则为有效
• TIM_OCMode_PWM2 : 与PWM1模式相反

• 🌿参数二：TIM5_OutputState_TypeDef ：指定比较输出状态

/** TIM5 Output Compare states */
typedef enum

    TIM5_OUTPUTSTATE_DISABLE           =((uint8_t)0x00),
    TIM5_OUTPUTSTATE_ENABLE            =((uint8_t)0x11)
TIM5_OutputState_TypeDef;

• TIM5_OUTPUTSTATE_DISABLE:禁止输出
• TIM5_OUTPUTSTATE_ENABLE:使能输出到对应引脚

• 🌿参数三：uint16_t TIM5_Pulse：设置捕获/比较寄存器 (TIM5_CCR1H和TIM5_CCR1L)装载值。
• 🌿参数四：TIM5_OCPolarity_TypeDef：指定输出比较极性。

/** TIM5 Output Compare Polarity */
typedef enum

    TIM5_OCPOLARITY_HIGH               =((uint8_t)0x00), // 极性为正
    TIM5_OCPOLARITY_LOW                =((uint8_t)0x22)// 极性为负
TIM5_OCPolarity_TypeDef;

---

🌻定时器5初始化函数

/**
  * @brief  Initializes the TIM5 Time Base Unit according to the specified parameters.
  * @param    TIM5_Prescaler specifies the Prescaler from TIM5_Prescaler_TypeDef.
  * @param    TIM5_Period specifies the Period value.
  * @retval None
  */
void TIM5_TimeBaseInit( TIM5_Prescaler_TypeDef TIM5_Prescaler,
                        uint16_t TIM5_Period)

  /* Set the Prescaler value */
  TIM5->PSCR = (uint8_t)(TIM5_Prescaler);
  /* Set the Autoreload value */
  TIM5->ARRH = (uint8_t)(TIM5_Period >> 8) ;
  TIM5->ARRL = (uint8_t)(TIM5_Period);

• 🍁参数一;TIM5_Prescaler_TypeDef :分频系数

/** TIM5 Prescaler */
typedef enum

    TIM5_PRESCALER_1     =((uint8_t)0x00),
    TIM5_PRESCALER_2      =((uint8_t)0x01),
    TIM5_PRESCALER_4      =((uint8_t)0x02),
    TIM5_PRESCALER_8      =((uint8_t)0x03),
    TIM5_PRESCALER_16     =((uint8_t)0x04),
    TIM5_PRESCALER_32     =((uint8_t)0x05),
    TIM5_PRESCALER_64     =((uint8_t)0x06),
    TIM5_PRESCALER_128    =((uint8_t)0x07),
    TIM5_PRESCALER_256    =((uint8_t)0x08),
    TIM5_PRESCALER_512    =((uint8_t)0x09),
    TIM5_PRESCALER_1024   =((uint8_t)0x0A),
    TIM5_PRESCALER_2048   =((uint8_t)0x0B),
    TIM5_PRESCALER_4096   =((uint8_t)0x0C),
    TIM5_PRESCALER_8192   =((uint8_t)0x0D),
    TIM5_PRESCALER_16384  =((uint8_t)0x0E),
    TIM5_PRESCALER_32768  =((uint8_t)0x0F)
TIM5_Prescaler_TypeDef;

• 🍁参数二：自动重装载寄存器(TIM5_ARRH 和TIM5_ARRL)：初值设定

---

✅开启内部时钟

默认是采用内部时钟，不启用也不影响。

/**
  * @brief  Enables or disables the Internal High Speed oscillator (HSI).
  * @param   NewState new state of HSIEN, value accepted ENABLE, DISABLE.
  * @retval None
  */
void CLK_HSICmd(FunctionalState NewState)

🔰时钟分频系数

• 必须指定的，不启用，则默认为复位值为系统时钟的1/8，

/**
  * @brief  Configures the HSI clock dividers.
  * @param   HSIPrescaler : Specifies the HSI clock divider to apply.
  * This parameter can be any of the @ref CLK_Prescaler_TypeDef enumeration.
  * @retval None
  */
void CLK_HSIPrescalerConfig(CLK_Prescaler_TypeDef HSIPrescaler)

🌼示例代码

/* Includes ------------------------------------------------------------------*/
#include "stm8s.h"

/* Private defines -----------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/

/* Private functions ---------------------------------------------------------*/
void Delay(uint16_t ms);


unsigned int pwm_duty = 0;
/* Private functions ---------------------------------------------------------*/

void main(void)

	GPIO_DeInit(GPIOD);
	TIM5_DeInit();
        
	GPIO_Init(GPIOD,GPIO_PIN_4,GPIO_MODE_OUT_PP_HIGH_FAST); //PD4 推挽输出 
	 CLK_HSICmd(ENABLE);   
  CLK_HSIPrescalerConfig(CLK_PRESCALER_HSIDIV1);//disENABLE 1/8 clk         
	TIM5_OC1Init(TIM5_OCMODE_PWM1, TIM5_OUTPUTSTATE_ENABLE, 1000,
                   TIM5_OCPOLARITY_HIGH);           
	TIM5_TimeBaseInit(TIM5_PRESCALER_1, 500);
	TIM5_Cmd(ENABLE);

  while(1)                   
    for(pwm_duty = 0; pwm_duty < 1000; pwm_duty += 2)
    
      TIM5_SetCompare1(pwm_duty);
      Delay(5);
                            
    for(pwm_duty = 1000; pwm_duty > 0; pwm_duty -= 2)
    
      TIM5_SetCompare1(pwm_duty);
      Delay(5);
    
  
  

void Delay(uint16_t ms)

	uint16_t i,j;
 for ( i=0; i<=ms; i++)
     for ( j=0; j<120; j++) // Nop = Fosc/4
        _asm("nop"); //Perform no operation

#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(u8* file, u32 line)
 
  /* 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) */

  /* Infinite loop */
  while (1)
  
  

#endif

更换PWM输出通道说明

• 更换PWM输出通道，需修改相关函数：

TIM5_OC1Init(TIM5_OCMODE_PWM1, TIM5_OUTPUTSTATE_ENABLE, 1000,
                   TIM5_OCPOLARITY_HIGH);  
TIM5_OC2Init(TIM5_OCMODE_PWM1, TIM5_OUTPUTSTATE_ENABLE, 1000,
                   TIM5_OCPOLARITY_HIGH); 
 TIM5_OC3Init(TIM5_OCMODE_PWM1, TIM5_OUTPUTSTATE_ENABLE, 1000,
                   TIM5_OCPOLARITY_HIGH);
                                                        
TIM5_SetCompare1(uint16_t Compare2);
TIM5_SetCompare2(uint16_t Compare2)
TIM5_SetCompare3(uint16_t Compare3)