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标题: STM32产生SPWM [打印本页]

作者: yuyang911220 时间: 2015-3-28 10:11 标题: STM32产生SPWM

/** @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输出配置说明，*/
/* - Prescaler = (TIM3CLK / TIM3 counter clock) - 1 选择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 */
/*转换周期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; //关闭互补输出
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); //这句的功能是让改变CCR2之后马上有效
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需要加上这句,貌似低级定时器不需要
}
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;
}
}
}

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