pwm波的输出电压总是高一倍怎么回事啊，我自己写了一下pwm的程序，但是测量时电压总是不对，我设置100的占空比理应输出0.32v但是实际数出0.63v其他的也是一样大一倍，下面是我写的程序static void TIM5_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* TIM3 clock enable */
//PCLK1¾­¹ý2±¶Æµºó×÷ΪTIM2µÄʱÖÓÔ´µÈÓÚ72MHz
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5, ENABLE);
/* GPIOA and GPIOB clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);
/*GPIOA Configuration: TIM2 channel 1 AND 2 and 3 and 4 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; // ¸´ÓÃÍÆÍìÊä³ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
}
static void TIM5_Mode_Config(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 999; //µ±¶¨Ê±Æ÷´Ó0¼ÆÊýµ½999£¬¼´Îª1000´Î£¬ÎªÒ»¸ö¶¨Ê±ÖÜÆÚ
TIM_TimeBaseStructure.TIM_Prescaler = 0; //ÉèÖÃÔ¤·ÖƵ£º²»Ô¤·ÖƵ£¬¼´Îª72MHz
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1 ; //ÉèÖÃʱÖÓ·ÖƵϵÊý£º²»·ÖƵ
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //ÏòÉϼÆÊýģʽ
TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure);
}
void TIM5_Mode1_Config(u16 CCR1_Val)
{
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM5_Mode_Config();
/* PWM1 Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //ÅäÖÃΪPWMģʽ1
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val; //ÉèÖÃÌø±äÖµ£¬µ±¼ÆÊýÆ÷¼ÆÊýµ½Õâ¸öֵʱ£¬µçƽ·¢ÉúÌø±ä
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //µ±¶¨Ê±Æ÷¼ÆÊýֵСÓÚCCR1_ValʱΪ¸ßµçƽ
TIM_OC1Init(TIM5, &TIM_OCInitStructure); //ʹÄÜͨµÀ2
TIM_OC1PreloadConfig(TIM5, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM5, ENABLE); // ʹÄÜTIM3ÖØÔؼĴæÆ÷ARR
/* TIM3 enable counter */
TIM_Cmd(TIM5, ENABLE); //ʹÄܶ¨Ê±Æ÷3
}
void TIM5_Mode2_Config(u16 CCR2_Val)
{
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM5_Mode_Config();
/* PWM1 Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //ÅäÖÃΪPWMģʽ1
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR2_Val; //ÉèÖÃͨµÀ2µÄµçƽÌø±äÖµ£¬Êä³öÁíÍâÒ»¸öÕ¼¿Õ±ÈµÄPWM
TIM_OC2Init(TIM5, &TIM_OCInitStructure); //ʹÄÜͨµÀ2
TIM_OC2PreloadConfig(TIM5, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM5, ENABLE); // ʹÄÜTIM3ÖØÔؼĴæÆ÷ARR
/* TIM3 enable counter */
TIM_Cmd(TIM5, ENABLE); //ʹÄܶ¨Ê±Æ÷3
}
void TIM5_Mode3_Config(u16 CCR3_Val)
{
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM5_Mode_Config();
/* PWM1 Mode configuration: Channel3 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //ÅäÖÃΪPWMģʽ1
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR3_Val; //ÉèÖÃͨµÀ3µÄµçƽÌø±äÖµ£¬Êä³öÁíÍâÒ»¸öÕ¼¿Õ±ÈµÄPWM
TIM_OC3Init(TIM5, &TIM_OCInitStructure); //ʹÄÜͨµÀ3
TIM_OC3PreloadConfig(TIM5, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM5, ENABLE); // ʹÄÜTIM3ÖØÔؼĴæÆ÷ARR
/* TIM3 enable counter */
TIM_Cmd(TIM5, ENABLE); //ʹÄܶ¨Ê±Æ÷3
}
void TIM5_Mode4_Config(u16 CCR4_Val)
{
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM5_Mode_Config();
/* PWM1 Mode configuration: Channel4 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //ÅäÖÃΪPWMģʽ1
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR4_Val; //ÉèÖÃͨµÀ4µÄµçƽÌø±äÖµ£¬Êä³öÁíÍâÒ»¸öÕ¼¿Õ±ÈµÄPWM
TIM_OC4Init(TIM5, &TIM_OCInitStructure); //ʹÄÜͨµÀ4
TIM_OC4PreloadConfig(TIM5, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM5, ENABLE); // ʹÄÜTIM3ÖØÔؼĴæÆ÷ARR
/* TIM3 enable counter */
TIM_Cmd(TIM5, ENABLE); //ʹÄܶ¨Ê±Æ÷3
} |
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