STM32L151 PWM输出示例

最近做个项目,需要用PWM控制4线风扇的速度,调试完后顺便将其记录下来.

typedef struct {u16 pwm_change_flag;u16 pwm_value;}Pwm_Fan_t;Pwm_Fan_t Pwm_Fan;void Pwm_Param_Init(void){Pwm_Fan.pwm_change_flag=0;Pwm_Fan.pwm_value=80;}//PD14->TIM4_CH3void PWM_GPIO_Config(void)  {   GPIO_InitTypeDef GPIO_InitStructure;  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOD, ENABLE);  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_14;   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;           // 复用推挽输出 GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_40MHz;   GPIO_Init(GPIOD, &GPIO_InitStructure); }/**************************************************************** 2017年8月14日14:37:57:cpu的风扇是使用25Khz pwm来调制的 ***************************************************************/  void TIM4_Config(u16 pwm){  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;  TIM_OCInitTypeDef  TIM_OCInitStructure;  /* PWM信号电平跳变值 */     u16 CCR3;  if(pwm>160-1)pwm=160-1;CCR3=pwm;RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);  GPIO_PinAFConfig(GPIOD, GPIO_PinSource14, GPIO_AF_TIM4); //对于L系列的,这句千万别漏掉了TIM_Cmd(TIM4, DISABLE);                          /* Time base configuration */                                            TIM_TimeBaseStructure.TIM_Period =160 - 1;//0xEA5F;  TIM_TimeBaseStructure.TIM_Prescaler = 8-1;                                  //设置预分频：预分频=2，即为72/3=24MHz  TIM_TimeBaseStructure.TIM_ClockDivision = 0;                                //设置时钟分频系数：不分频  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;                 //向上计数溢出模式  TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);  /* PWM1 Mode configuration: Channel3 */  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;                           //配置为PWM模式1  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;                TIM_OCInitStructure.TIM_Pulse = CCR3;                                       //设置跳变值，当计数器计数到这个值时，电平发生跳变  TIM_OCInitStructure.TIM_OCPolarity =TIM_OCPolarity_Low;                     //当定时器计数值小于CCR1时为低电平  TIM_OC3Init(TIM4, &TIM_OCInitStructure);                                    //使能通道3     TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);  TIM_ARRPreloadConfig(TIM4, ENABLE);                                         //使能TIM4重载寄存器ARR  /* TIM4 enable counter */  TIM_Cmd(TIM4, ENABLE);                                                      //使能TIM4   }