最近要用STM32來輸出PWM，花了一個晚上寫完了，記錄一下

（我用的是STM32F303CCT6）

1.打開定時器時鐘

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

2.打開輸出引腳的GPIO時鐘

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

3.配置相應引腳為 AF模式（具體AFx要看手冊）

GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_2);

4.初始化輸出引腳為 AF模式， 推挽輸出， 上拉， 速度為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.定時器設置（ 頻率 = 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;//重復溢出多少次進中斷
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStruct);

6.定時器通道設置 PWM模式1， 輸出極性高， 允許輸出

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.打開定時器

TIM_Cmd(TIM3, ENABLE);

8.設置占空比 Duty = pwmval ÷ arr

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

9.全部代碼如下

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;//重復溢出多少次進中斷
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輸出的 頻率，占空比，模式 有好幾個不同的參數設置

STM32輸出PWM