笔记-STM32F407 TIM输出PWM

//初始化定时器
void TIM2_PWM_Init(u16 arr, u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;

TIM_DeInit(TIM2);	

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);	//使能定时器时钟

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);//使能GPIO的时钟

//设置该引脚为复用输出功能,输出TIM2 CH1的PWM脉冲波形
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15; //TIM2_CH1对应
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Fast_Speed;
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIO
GPIO_PinAFConfig(GPIOA,GPIO_PinSource15,GPIO_AF_TIM2);

//初始化TIM
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值
TIM_TimeBaseStructure.TIM_ClockDivision =TIM_CKD_DIV1; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位

//初始化TIM2 Channel1 PWM模式	
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高
TIM_OCInitStructure.TIM_Pulse = (arr+1)/2; //设置待装入捕获比较寄存器的脉冲值，高于脉冲值就会产生高电平
TIM_OC1Init(TIM2, &TIM_OCInitStructure);  //根据T指定的参数初始化外设

TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable);  //使能TIM1在CCR1上的预装载寄存器
	
TIM_Cmd(TIM2, DISABLE);

}

//5kHz PWM定时器
//定时器2时钟84M，分频系数84，所以84M/84=1000Khz的计数频率，计数1次为1us
TIM2_PWM_Init(1000/5-1, 84 - 1);
TIM_Cmd(TIM2, ENABLE);