STM32L151 PWM output example

I recently did a project that required me to use PWM to control the speed of a 4-wire fan. After debugging, I recorded it.

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; // Multiplexed push-pull output 

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); 

}

/****************************************************** *************** 

August 14, 2017 14:37:57: The CPU fan is modulated using 25Khz pwm

 *************************************************** *************/  

void TIM4_Config(u16 pwm)

{  

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;  

TIM_OCInitTypeDef TIM_OCInitStructure;  

/* PWM signal level jump value*/     

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); //For L series, don't miss this sentence

TIM_Cmd(TIM4, DISABLE);                          

/* Time base configuration */                                            

TIM_TimeBaseStructure.TIM_Period =160 - 1;//0xEA5F;  

TIM_TimeBaseStructure.TIM_Prescaler = 8-1; //Set prescaler: prescaler = 2, which is 72/3 = 24MHz  

TIM_TimeBaseStructure.TIM_ClockDivision = 0; //Set the clock division factor: no division  

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //Upward counting overflow mode  

TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);  

/* PWM1 Mode configuration: Channel3 */  

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //Configure to PWM mode 1  

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;                

TIM_OCInitStructure.TIM_Pulse = CCR3; //Set the jump value. When the counter counts to this value, the level jumps.  

TIM_OCInitStructure.TIM_OCPolarity =TIM_OCPolarity_Low; //When the timer count value is less than CCR1, it is low level  

TIM_OC3Init(TIM4, &TIM_OCInitStructure); //Enable channel 3     

TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);  

TIM_ARRPreloadConfig(TIM4, ENABLE); //Enable TIM4 reload register ARR  

/* TIM4 enable counter */  

TIM_Cmd(TIM4, ENABLE); //Enable TIM4   

}