【灵动微电子MM32F0121测评】+3PWM驱动LED灯做呼吸灯

在之前做了开箱与串口打印，这次就做一个呼吸灯，用PWM波驱动开发板自带的LED,开发板的LED是在B14,B15 io口，
用TIM1驱动，关键代理如下

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void TIM1_Configure(void)

{

    RCC_ClocksTypeDef       RCC_Clocks;

    GPIO_InitTypeDef        GPIO_InitStruct;

    TIM_OCInitTypeDef       TIM_OCInitStruct;

    TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;

    uint32_t                TIM_ClockFrequency = 0;

    uint32_t                HPRE = 0, PPRE2 = 0;



    uint32_t TimerPeriod = 0, Channel1Pulse = 0, Channel2Pulse = 0, Channel3Pulse = 0;



    HPRE  = READ_BIT(RCC->CFGR, RCC_CFGR_HPRE)  >> RCC_CFGR_HPRE_Pos;

    PPRE2 = READ_BIT(RCC->CFGR, RCC_CFGR_PPRE2) >> RCC_CFGR_PPRE2_Pos;



    RCC_GetClocksFreq(&RCC_Clocks);



    if (HPRE < 8)

    {

        if (PPRE2 < 4)

        {

            TIM_ClockFrequency = RCC_Clocks.PCLK1_Frequency;

        }

        else

        {

            TIM_ClockFrequency = RCC_Clocks.PCLK1_Frequency * 2;

        }

    }

    else

    {

        if (PPRE2 < 4)

        {

            TIM_ClockFrequency = RCC_Clocks.PCLK1_Frequency * 2;

        }

        else

        {

            TIM_ClockFrequency = RCC_Clocks.PCLK1_Frequency * 4;

        }

    }



    /* Compute the value to be set in ARR regiter to generate signal frequency at 100 Khz */

    TimerPeriod = TIM_ClockFrequency / 100000;



    /* Compute CCR1 value to generate a duty cycle at 75% for channel 1 */

    Channel1Pulse = (uint32_t)750 * TimerPeriod / 1000;



    /* Compute CCR2 value to generate a duty cycle at 50% for channel 2 */

    Channel2Pulse = (uint32_t)500 * TimerPeriod / 1000;



    /* Compute CCR3 value to generate a duty cycle at 25% for channel 3 */

    Channel3Pulse = (uint32_t)250 * TimerPeriod / 1000;



    RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);



    TIM_TimeBaseStructInit(&TIM_TimeBaseInitStruct);

    TIM_TimeBaseInitStruct.TIM_Prescaler         = 0;

    TIM_TimeBaseInitStruct.TIM_CounterMode       = TIM_CounterMode_Up;

    TIM_TimeBaseInitStruct.TIM_Period            = TimerPeriod;

    TIM_TimeBaseInitStruct.TIM_ClockDivision     = TIM_CKD_Div1;

    TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0;

    TIM_TimeBaseInit(TIM1, &TIM_TimeBaseInitStruct);



    TIM_OCStructInit(&TIM_OCInitStruct);

    TIM_OCInitStruct.TIM_OCMode       = TIM_OCMode_PWM1;

    TIM_OCInitStruct.TIM_OutputState  = TIM_OutputState_Enable;

    TIM_OCInitStruct.TIM_Pulse        = 0;

    TIM_OCInitStruct.TIM_OCPolarity   = TIM_OCPolarity_High;

    TIM_OCInitStruct.TIM_OCIdleState  = TIM_OCIdleState_Set;



    TIM_OCInitStruct.TIM_Pulse = Channel1Pulse;

    TIM_OC1Init(TIM1, &TIM_OCInitStruct);



    TIM_OCInitStruct.TIM_Pulse = Channel2Pulse;

    TIM_OC2Init(TIM1, &TIM_OCInitStruct);



    TIM_OCInitStruct.TIM_Pulse = Channel3Pulse;

    TIM_OC3Init(TIM1, &TIM_OCInitStruct);





    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);







    GPIO_PinAFConfig(GPIOB, GPIO_PinSource14,  GPIO_AF_7);   /* TIM1_CH1 */



    GPIO_PinAFConfig(GPIOB, GPIO_PinSource15,  GPIO_AF_7);   /* TIM1_CH2 */







    GPIO_StructInit(&GPIO_InitStruct);



    GPIO_InitStruct.GPIO_Pin   = GPIO_Pin_14 | GPIO_Pin_15 ;



    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_High;



    GPIO_InitStruct.GPIO_Mode  = GPIO_Mode_AF_PP;



    GPIO_Init(GPIOB, &GPIO_InitStruct);



    TIM_Cmd(TIM1, ENABLE);



    TIM_CtrlPWMOutputs(TIM1, ENABLE);

}

然后在例程中的这里改一下

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void TIM1_PWM_Output_Sample(void)

{

        uint16_t i =0;

    printf("\r\nTest %s", __FUNCTION__);



    TIM1_Configure();



    while (1)

    {

         TIM1->CCR1 = 1440 - (i++%1440);



         TIM1->CCR2 = (i++%1440);







          PLATFORM_DelayMS(1);

    }

}

下面上效果

PWM驱动LED灯做呼吸灯