我的定时器为什么出不来PWM波啊，官方的例子，有问题吗？

nannan · 发表于 2015-8-2 15:54:22

#include "sys.h"
#include "stm32f10x.h"

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
uint16_t CCR1_Val = 333;
uint16_t CCR2_Val = 249;
uint16_t CCR3_Val = 166;
uint16_t CCR4_Val = 83;
uint16_t PrescalerValue = 0;

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
int main(void)
{
/* System Clocks Configuration */
RCC_Configuration();

/* GPIO Configuration */
GPIO_Configuration();

/* Compute the prescaler value */
PrescalerValue = (uint16_t) (SystemCoreClock / 24000000) - 1;
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 665;
TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

/* PWM1 Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

TIM_OC1Init(TIM3, &TIM_OCInitStructure);

TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

/* PWM1 Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR2_Val;

TIM_OC2Init(TIM3, &TIM_OCInitStructure);

TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

/* PWM1 Mode configuration: Channel3 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR3_Val;

TIM_OC3Init(TIM3, &TIM_OCInitStructure);

TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);

/* PWM1 Mode configuration: Channel4 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR4_Val;

TIM_OC4Init(TIM3, &TIM_OCInitStructure);

TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);

TIM_ARRPreloadConfig(TIM3, ENABLE);

/* TIM3 enable counter */
TIM_Cmd(TIM3, ENABLE);

while(1)
{

}
}

void RCC_Configuration(void)
{
/* TIM3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

/* GPIOA and GPIOB clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
}

void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

/*GPIOB Configuration: TIM3 channel1, 2, 3 and 4 */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOC, &GPIO_InitStructure);

GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE);
}