灵动微MM32F003硬件最小系统 --- PWM例程解析【17

本例程通过将PB0、PB1两个GPIO分别配置为TIM1_CH2N、TIM1_CH2，实现两个LED的交替闪烁。

1 GPIO初始化

void initGPIO_Timer1(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource0, GPIO_AF_2);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource1, GPIO_AF_6);

    GPIO_InitStructure.GPIO_Pin  =  GPIO_Pin_0;                                //TIM1_CH2N
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
    GPIO_InitStructure.GPIO_Pin  =  GPIO_Pin_1;                                //TIM1_CH2
    GPIO_Init(GPIOB, &GPIO_InitStructure);
}

2 TIM1初始化

void initTIM1(u16 prescaler, u16 period, u16 dutyCycle)
{
    TIM_TimeBaseInitTypeDef TIM_StructInit;
    TIM_OCInitTypeDef  TIM_OCInitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

    TIM_TimeBaseStructInit(&TIM_StructInit);
    TIM_StructInit.TIM_Period = period;
    TIM_StructInit.TIM_Prescaler = prescaler;
    TIM_StructInit.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_StructInit.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_StructInit.TIM_RepetitionCounter = 0;
    TIM_TimeBaseInit(TIM1, &TIM_StructInit);

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
    TIM_OCInitStructure.TIM_Pulse = dutyCycle;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
    TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
    TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
    TIM_OC2Init(TIM1, &TIM_OCInitStructure);
    TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);

    TIM_ARRPreloadConfig(TIM1, ENABLE);
    TIM_ITConfig(TIM1, TIM_IT_CC2, ENABLE);

    TIM_CtrlPWMOutputs(TIM1, ENABLE);
}

3 中断初始化

void initNVIC_TIM1(void)
{
    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel = TIM1_CC_IRQn;                          // Config TIM1_CC_IRQn NVIC config
    NVIC_InitStructure.NVIC_IRQChannelPriority = 0;                             // PreemptionPriority : 1
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                             // Enable IRQn
    NVIC_Init(&NVIC_InitStructure);
}

4 中断服务程序

void TIM1_CC_IRQHandler()
{
    if (TIM_GetITStatus(TIM1, TIM_IT_CC2) != RESET) {
        TIM_ClearITPendingBit(TIM1, TIM_IT_CC2);                                // Clear the CC2 flag
    }
}

5 main函数

int main(void)
{
    initGPIO_Timer1();
    initTIM1(479, 29999, 15000);                                                     //config TIM to PWM output
    initNVIC_TIM1();
    OnTIM1();                                                                   //enable TIM;

    while(1) {
    }
}

官方例程的修正已基本完成，需要程序的同学可以到百度网盘下载。
提取码：0o5i