/** @author Mei Jilin
    @date   2013/9/2
    @brief  加入生成SPWM部分
**/
#include "timer.h"
#include "led.h"
static uint16_t CCR3_Val = 1800;
static uint16_t PrescalerValue = 0;

/*PWM輸出配置說明，*/
/* - Prescaler = (TIM3CLK / TIM3 counter clock) - 1 選擇TIMER工作在36MHZ

    The TIM3 is running at 36 MHz: TIM3 Frequency = TIM3 counter clock/(ARR + 1)
                                                  = 36 MHz / 3600 = 10 KHz
    TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR)* 100 */
	/*轉換週期10K*/
void PWM_Init(void)
{
	TIM_TimeBaseInitTypeDef  	TIM_TimeBaseStructure;
	TIM_OCInitTypeDef        	TIM_OCInitStructure;
	GPIO_InitTypeDef 			GPIO_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;    
	 	/* TIM3 clock enable */
   	RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

  	/* GPIOA and GPIOB clock enable */
  	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB|
                         	 RCC_APB2Periph_AFIO, ENABLE);
  	/* GPIOA Configuration:TIM3 Channel1, 2, 3 and 4 as alternate function push-pull */
  	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
  	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  	GPIO_Init(GPIOA, &GPIO_InitStructure);
    
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;      //TIM1_CH1N
    GPIO_Init(GPIOB, &GPIO_InitStructure);
	
	 /* Compute the prescaler value */
  	PrescalerValue = (uint16_t) (SystemCoreClock / 36000000) - 1; //TIMER2 - 36MHZ
  	/* Time base configuration */
  	TIM_TimeBaseStructure.TIM_Period = 3600;	 				/*TIM3_ARR = 2879,12.5Khz*/
  	TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
  	TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
  	TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

    /* Channel 1, 2,3 and 4 Configuration in PWM mode */
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable; //關閉互補輸出
    TIM_OCInitStructure.TIM_Pulse = CCR3_Val;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
    TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
    TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Set;
    TIM_OC1Init(TIM1, &TIM_OCInitStructure);
    
  	TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable); //這句的功能是讓改變CCR2之後馬上有效    
	TIM_ITConfig(TIM1, TIM_IT_CC1, ENABLE);
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
	NVIC_InitStructure.NVIC_IRQChannel = TIM1_CC_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 6;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);    
        
  	TIM_Cmd(TIM1, ENABLE);	
    /* TIM1 Main Output Enable */
    TIM_CtrlPWMOutputs(TIM1, ENABLE);   //TIM1需要加上這句,貌似低階定時器不需要
}
uint16_t Duty[] = {1800,1856,1912,1968,2023,2078,2131,2183,2233,2282,2329,2373,2416,2456,2493,
    2528,2559,2588,2614,2636,2655,2671,2684,2692,2698,2699,2698,2692,2684,2671,2655,2636,2614,
    2588,2559,2528,2493,2456,2416,2373,2329,2282,2233,2183,2131,2078,2023,1968,1912,1856,1800,
    1743,1687,1631,1576,1521,1468,1416,1366,1317,1270,1226,1183,1143,1106,1071,1040,1011,985,
    963,944,928,915,907,901,900,901,907,915,928,944,963,985,1011,1040,1071,1106,1143,1183,1226,
    1270,1317,1366,1416,1468,1521,1576,1631,1687,1743,1799,1799};
uint16_t count = 0;
uint16_t num = sizeof(Duty)/(sizeof(Duty[0]));
void TIM1_CC_IRQHandler(void)
{
  if (TIM_GetITStatus(TIM1, TIM_IT_CC1) != RESET)
  {
    TIM1->SR = (uint16_t)~TIM_IT_CC1;
    TIM1->CCR1 = Duty[count];
    count++;
    if(count==num)
    {
        count=0;
    }
  }
}