#include "pwm_led.h"

static uint32_t PWM_arr = 0;
static uint32_t PWM_prescaler = 0;
static int16_t brightness = 0;                                  
void PWM_LED_Init(void);
static void GPIO_Configure(void)
{
    GPIO_InitTypeDef GPIOInitType;
    
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);
    GPIOInitType.GPIO_Pin = GPIO_Pin_5;
    GPIOInitType.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIOInitType.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3,ENABLE);
    GPIO_Init(GPIOB,&GPIOInitType);
}

static void TIM_Configure(void)
{
    TIM_TimeBaseInitTypeDef TIMInitType;
    TIMInitType.TIM_Period = PWM_arr; //设置定时器的周期
    TIMInitType.TIM_Prescaler = PWM_prescaler;
    TIMInitType.TIM_ClockDivision = TIM_CKD_DIV1;
    TIMInitType.TIM_CounterMode = TIM_CounterMode_Up;
    
    TIM_TimeBaseInit(TIM3,&TIMInitType);

}

static void PWM_Configure(void)
{
    TIM_OCInitTypeDef TIMOCInitType;
    TIMOCInitType.TIM_OCMode = TIM_OCMode_PWM1; //pwm1模式即计数值小于pulse有效，大于pulse小于arr为无效电平
    TIMOCInitType.TIM_OCPolarity = TIM_OCPolarity_Low;  //设置为低电平有效
    TIMOCInitType.TIM_OutputState = ENABLE;
    TIM_OC2Init(TIM3,&TIMOCInitType);
	TIM_OC2PreloadConfig(TIM3,TIM_OCPreload_Enable);
	TIM_ARRPreloadConfig(TIM3,ENABLE);//使能预装载寄存器
	TIM_Cmd(TIM3,ENABLE);
}


void User_PWM_Init(uint32_t arr,uint32_t prescaler)
{
    PWM_arr = arr;
    PWM_prescaler = prescaler;

    GPIO_Configure();
    TIM_Configure();
    PWM_Configure();
}

void BrightnessControl()
{
    brightness += 50;
    if(brightness > PWM_arr)
        brightness = 0;
    TIM_SetCompare2(TIM3,brightness);
}