STM32输出PWM

最近要用STM32来输出PWM，花了一个晚上写完了，记录一下

（我用的是STM32F303CCT6）

1.打开定时器时钟

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

2.打开输出引脚的GPIO时钟

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

3.配置相应引脚为 AF模式（具体AFx要看手册）

GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_2);

4.初始化输出引脚为 AF模式， 推挽输出， 上拉， 速度为GPIO_Speed_Level_3

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF; //PA6
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_Level_3;
GPIO_Init(GPIOA, &GPIO_InitStruct);

5.定时器设置（ 频率 = 72000000÷（arr+1）÷（psc+1））

TIM_TimeBaseStruct.TIM_Period = 999; //arr
TIM_TimeBaseStruct.TIM_Prescaler = 1439;//psc
TIM_TimeBaseStruct.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStruct.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStruct.TIM_RepetitionCounter = 0;//重复溢出多少次进中断
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStruct);

6.定时器通道设置 PWM模式1， 输出极性高， 允许输出

TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStruct);

7.打开定时器

TIM_Cmd(TIM3, ENABLE);

8.设置占空比 Duty  =  pwmval  ÷  arr

TIM_SetCompare1(TIM3, 99);// pwmval Duty = arr/pwmval

9.全部代码如下

GPIO_InitTypeDef GPIO_InitStruct;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStruct;
TIM_OCInitTypeDef TIM_OCInitStruct;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_2);

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF; 
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_Level_3;
GPIO_Init(GPIOA, &GPIO_InitStruct);

TIM_TimeBaseStruct.TIM_Period = 999; //arr
TIM_TimeBaseStruct.TIM_Prescaler = 1439;// psc 
TIM_TimeBaseStruct.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStruct.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStruct.TIM_RepetitionCounter = 0;//重复溢出多少次进中断
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStruct);

TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStruct);
TIM_OC2Init(TIM3, &TIM_OCInitStruct);

TIM_Cmd(TIM3, ENABLE);

TIM_SetCompare1(TIM3, 99);//pwmval

在STM32中，PWM输出的 频率，占空比，模式 有好几个不同的参数设置