stm32f103c8t6PA8输出PWM波

### STM32F103C8T6 PA8引脚PWM配置

PA8引脚可以用于定时器1的通道1 (TIM1_CH1)，而不是TIM2。为了使PA8引脚能够输出PWM信号，需将其设置为复用推挽输出模式并正确初始化定时器1的相关寄存器[^1]。

#### 初始化GPIO和定时器
首先，确保PA8被配置成复用功能(AF)以允许其作为定时器的功能引脚工作。接着，通过设定预分频系数(PSC)以及自动重装载值(ARR)来定义PWM频率；再者，利用捕获/比较寄存器(CCRx)调整占空比。

// GPIO Initialization Function
void MX_GPIO_Init(void){
    __HAL_RCC_GPIOA_CLK_ENABLE(); // Enable clock access to port A
    
    GPIO_InitTypeDef GPIO_InitStruct = {0};
    
    /* Configure PA8 as alternate function push-pull */
    GPIO_InitStruct.Pin = GPIO_PIN_8;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP; 
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}

// TIM1 PWM Configuration and Start
static void MX_TIM1_PWM_Config(void){
    __HAL_RCC_TIM1_CLK_ENABLE();
    
    TIM_HandleTypeDef htim1;
    TIM_OC_InitTypeDef sConfigOC;

    htim1.Instance = TIM1;
    htim1.Init.Prescaler = 7999;      // Set prescaler value based on system clock frequency
    htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
    htim1.Init.Period = 999;          // Set period for desired PWM frequency
    htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
    if(HAL_TIM_PWM_Init(&htim1)!= HAL_OK){Error_Handler();}
     
    sConfigOC.OCMode = TIM_OCMODE_PWM1;
    sConfigOC.Pulse = 499;            // Initial duty cycle of 50%
    sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
    sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
    sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
    sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
    sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
    
    if(HAL_TIM_PWM_ConfigChannel(&htim1,&sConfigOC,TIM_CHANNEL_1) != HAL_OK){Error_Handler();}
   
    HAL_TIM_PWM_Start(&htim1,TIM_CHANNEL_1);  
}

此代码片段展示了如何启用GPIO端口A上的时钟，并将PA8配置为复用推挽输出模式以便于连接到定时器1 CH1。随后，对TIM1进行了基本配置，设置了预分频器、计数方向、周期长度等参数，并指定了CH1的工作方式为PWM模式1。最后一步则是开启该通道的PWM输出。