【ARM 的PWM输出注意点】

APM32 M0的PWM初始化

/*!
 * @brief       TMR1 PWM Output Init
 *
 * @param       None
 *
 * @retval      None
 *
 * @note       
 */
void APM_MINI_TMR1_PWMOutPut_Init(void)
{
    TMR_TimeBase_T  timeBaseConfig;
    TMR_OCConfig_T  occonfig;
    GPIO_Config_T   gpioconfig;
    /** Enable Clock*/
    RCM_EnableAHBPeriphClock(RCM_AHB_PERIPH_GPIOA);
    RCM_EnableAPB2PeriphClock(RCM_APB2_PERIPH_SYSCFG);
    RCM_EnableAPB2PeriphClock(RCM_APB2_PERIPH_TMR1);
   
    /**  Connect TMR1 to CH4 */
    GPIO_ConfigPinAF(GPIOA, GPIO_PIN_SOURCE_11, GPIO_AF_PIN2); 
    gpioconfig.mode  = GPIO_MODE_AF;
    gpioconfig.outtype = GPIO_OUT_TYPE_PP;
    gpioconfig.pin   = GPIO_PIN_11; 
    gpioconfig.pupd  = GPIO_PUPD_PU;
    gpioconfig.speed = GPIO_SPEED_50MHz;
    GPIO_Config(GPIOA,&gpioconfig);
     
      /** Set clockDivision = 1 */
    timeBaseConfig.clockDivision =  TMR_CKD_DIV1;
      /** Up-counter */
    timeBaseConfig.counterMode =  TMR_COUNTER_MODE_UP;
      /** Set divider = 47 .So TMR1 clock freq ~= 48/(47+1) = 1MHZ */
    timeBaseConfig.div =7;// 47 ; 
      /** Set counter = 0xffff */
    timeBaseConfig.period = 40;
      /** Repetition counter = 0x0 */
    timeBaseConfig.repetitionCounter =  0;
    TMR_ConfigTimeBase(TMR1,&timeBaseConfig);
    
     /** PWM1 mode */
    occonfig.OC_Mode =  TMR_OC_MODE_PWM1;
     /** Idle State is reset */
    occonfig.OC_Idlestate  = TMR_OCIDLESTATE_RESET;
     /** NIdle State is reset */
    occonfig.OC_NIdlestate = TMR_OCNIDLESTATE_RESET;
     /** Enable CH1N ouput */
    occonfig.OC_OutputNState =  TMR_OUTPUT_NSTATE_DISABLE;
     /** Enable CH1 ouput */
    occonfig.OC_OutputState  =  TMR_OUTPUT_STATE_ENABLE;
     /** CH1  polarity is high */
    occonfig.OC_Polarity  = TMR_OC_POLARITY_HIGH;
     /** CH1N polarity is high */
    occonfig.OC_NPolarity = TMR_OC_NPOLARITY_HIGH;
     /** Set compare value */
    occonfig.Pulse = 40;
    TMR_OC4Config(TMR1,&occonfig);
        
    /** Enable PWM output */
    TMR_EnablePWMOutputs(TMR1);
    /**  Enable TMR1  */
    TMR_Enable(TMR1);
    //set the default value;
		PWM_DUTY_SET=PWR_ON_DEFAULT_DUTY;
}

改变PWM在占空比：

TMR_SetCompare4(TMR1,PWR_ON_DEFAULT_DUTY_RUNTIME);	//开机FAN为60%运行10秒

如果需要改变PWM的通道及定时器请注意：

STM32 的PWM初始化

/****************************************************************************
* 名    称: void TIM1_PWM_Init(u32 auto_data,u32 fractional)
* 功    能：PWM输出初始化
* 入口参数：auto_data: 自动重装值
*           fractional: 时钟预分频数
* 返回参数：无
* 说    明：设置PA9(TIM1_CH2)输出PWM波      
****************************************************************************/
void TIM1_PWM_Init(u32 auto_data,u32 fractional)
{		 					 
	GPIO_InitTypeDef GPIO_InitStructure;
	TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
	TIM_OCInitTypeDef  TIM_OCInitStructure;
	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1,ENABLE);  	 //TIM5时钟使能    
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);  //使能PORTA时钟	
	
	GPIO_PinAFConfig(GPIOA,GPIO_PinSource9,GPIO_AF_TIM1); //GPIOA9复用为定时器1
	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;           //GPIOA9
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;        //复用功能
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;	//速度100MHz
	GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;      //推挽复用输出
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;        //上拉
	GPIO_Init(GPIOA,&GPIO_InitStructure);              //初始化PA9
	  
	TIM_TimeBaseStructure.TIM_Prescaler=fractional;  //定时器分频
	TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
	TIM_TimeBaseStructure.TIM_Period=auto_data;      //自动重装载值
	TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; 
	
	TIM_TimeBaseInit(TIM1,&TIM_TimeBaseStructure);  //初始化定时器5
	
	//初始化TIM1 Channel2 PWM模式	 
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;  //选择定时器模式:TIM脉冲宽度调制模式2
	TIM_OCInitStructure.TIM_Pulse = auto_data/2;  	//占空比 50%
 	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;  //比较输出使能
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;  //输出极性:TIM输出比较极性低
	TIM_OC2Init(TIM1, &TIM_OCInitStructure);   //根据T指定的参数初始化外设TIM1 4OC1

	TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);  //使能TIM1在CCR2上的预装载寄存器
 
  TIM_ARRPreloadConfig(TIM1,ENABLE);  
	
	TIM_Cmd(TIM1, ENABLE);  //使能TIM1
}  

改变PWM在占空比：

TIM_SetCompare2(TIM1,pwmzkb);	

如果需要改变PWM的通道及定时器请注意：
文章来源地址https://uudwc.com/A/0kB8k