STM32 定时器(二)——定时器发生不同频率的PWM

STM32发生PWM是十分的便利的，要需求简略的设置定时器，立刻发生！当然，简略的设置关于新手来产，也是费事的，首要包含：

（1）使能定时器时钟：RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

（2）界说相应的GPIO：

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //下拉接地，检测输入的高电平
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOA, &GPIO_InitStructure);

（3）如果是发生PWM（频率不变，占空比可变），记住翻开PWM操控，在TIM_Configuration()中。

TIM_Cmd(TIM3,ENABLE);

TIM_CtrlPWMOutputs(TIM1,ENABLE);

使用定时器发生不同频率的PWM

有时分，需求发生不同频率的PWM，这个时分，设置与发生相同PWM的程序，有要害的不一样。

（一）设置的原理

使用改动定时器输出比较通道的捕获值，当输出通道捕获值发生中止时，在中止中将捕获值改动，这时，输出的I/O会发生一个电平翻转，使用这种方法，完成不同频率的PWM输出。

（二）要害设置

在定时器设置中：TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);

在中止函数中： if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
capture = TIM_GetCapture2(TIM3);
TIM_SetCompare2(TIM3, capture + Key_Value);
}

一个定时器四个通道，别离发生不同频率（这个比如网上也有）

vu16 CCR1_Val = 32768;
vu16 CCR2_Val = 16384;
vu16 CCR3_Val = 8192;
vu16 CCR4_Val = 4096;

void TIM_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 2;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle; //PWM形式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //正向通道有用
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;//反向通道无效
TIM_OCInitStructure.TIM_Pulse = CCR1_Val; //占空时刻
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High; //互补端的极性
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;

TIM_OC1Init(TIM2,&TIM_OCInitStructure); //通道1
TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Disable);

TIM_OCInitStructure.TIM_Pulse = CCR2_Val; //占空时刻
TIM_OC2Init(TIM2,&TIM_OCInitStructure); //通道2
TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Disable);

TIM_OCInitStructure.TIM_Pulse = CCR3_Val; //占空时刻
TIM_OC3Init(TIM2,&TIM_OCInitStructure); //通道3
TIM_OC3PreloadConfig(TIM2, TIM_OCPreload_Disable);

TIM_OCInitStructure.TIM_Pulse = CCR4_Val; //占空时刻
TIM_OC4Init(TIM2,&TIM_OCInitStructure); //通道4
TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Disable);

TIM_Cmd(TIM2,ENABLE);

//TIM_CtrlPWMOutputs(TIM2,ENABLE);

TIM_ITConfig(TIM2, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);

}

void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6|GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //开漏输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //开漏输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入
GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入
GPIO_Init(GPIOC, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入
GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOA, &GPIO_InitStructure);
}

void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(&NVIC_InitStructure);
}