[嵌入式]stm32f407之通用定时器产生PWM波

1.初始化

1.定义相关变量

GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;

2.打开定时器和GPIO时钟

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM14, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF, ENABLE);

3.配置GPIO口为复用功能输出

GPIO_PinAFConfig(GPIOF, GPIO_PinSource9, GPIO_AF_TIM14);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOF, &GPIO_InitStructure);

4.配置定时器基本配置寄存器

TIM_TimeBaseInitStructure.TIM_Period = arr;
TIM_TimeBaseInitStructure.TIM_Prescaler = psc;
TIM_TimeBaseInitStructure.TIM_ClockDivision = 0;
TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStructure);

5.配置定时器输出PWM功能

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OC1Init(TIM14, &TIM_OCInitStructure);

6.使能定时器

TIM_Cmd(TIM14, ENABLE);

2.改变PWM大小

TIM_SetCompare1(TIM14,led0pwmval);