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_CH3
void 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
}
『本文转载自网络,版权归原作者所有,如有侵权请联系删除』