[N32L43X评测] 7.PWM测试

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[N32L43X评测] 7.PWM测试 [复制链接]

 

本篇介绍TIM3定时器输出PWM测试

硬件连接

TIM3CH1  ——  PA6

TIM3CH2  ——  PA7

软件代码

TIM3输出PWM频率设置为10kHz，CH1占空比50%，CH2占空比25%

/**
 * @brief PWM初始化
 */
void hal_pwmInitial(void)
{
    GPIO_InitType GPIO_InitStructure;
    TIM_TimeBaseInitType TIM_TimeBaseStructure;
    OCInitType TIM_OCInitStructure;

    /* TIM3 clock enable */
    RCC_EnableAPB1PeriphClk(RCC_APB1_PERIPH_TIM3, ENABLE);
    /* GPIOA and GPIOB clock enable */
    RCC_EnableAPB2PeriphClk(RCC_APB2_PERIPH_GPIOA | RCC_APB2_PERIPH_GPIOB | RCC_APB2_PERIPH_AFIO, ENABLE);

    GPIO_InitStruct(&GPIO_InitStructure);
    /* GPIOA Configuration:TIM3 Channel1, 2, 3 and 4 as alternate function push-pull */
    GPIO_InitStructure.Pin        = GPIO_PIN_6 | GPIO_PIN_7;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Current = GPIO_DC_4mA;
    GPIO_InitStructure.GPIO_Alternate = GPIO_AF2_TIM3;
    GPIO_InitPeripheral(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.Pin = GPIO_PIN_0 | GPIO_PIN_1;
    GPIO_InitStructure.GPIO_Alternate = GPIO_AF2_TIM3;
    GPIO_InitPeripheral(GPIOB, &GPIO_InitStructure);
    /* -----------------------------------------------------------------------
    TIM3 Frequency = 54MHz/Prescaler*Period = 54M/54/100 = 10kHz(0.1ms)
    TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR)* 100 = 50%
    TIM3 Channel2 duty cycle = (TIM3_CCR2/ TIM3_ARR)* 100 = 25%
    TIM3 Channel3 duty cycle = (TIM3_CCR3/ TIM3_ARR)* 100 = 75%
    TIM3 Channel4 duty cycle = (TIM3_CCR4/ TIM3_ARR)* 100 = 10%
    ----------------------------------------------------------------------- */
    /* Time base configuration */
    TIM_TimeBaseStructure.Period    = 100-1; //1us*100 = 100us = 0.1ms 10kHz
    TIM_TimeBaseStructure.Prescaler = PrescalerValue1; //54000000/54 = 1MHz 1us
    TIM_TimeBaseStructure.ClkDiv    = 0;
    TIM_TimeBaseStructure.CntMode   = TIM_CNT_MODE_UP;
    TIM_InitTimeBase(TIM3, &TIM_TimeBaseStructure);
    /* PWM1 Mode configuration: Channel1 */
    TIM_OCInitStructure.OcMode      = TIM_OCMODE_PWM1;
    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR1_Value;
    TIM_OCInitStructure.OcPolarity  = TIM_OC_POLARITY_HIGH;
    TIM_InitOc1(TIM3, &TIM_OCInitStructure);
    TIM_ConfigOc1Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);
    /* PWM1 Mode configuration: Channel2 */
    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR2_Value;
    TIM_InitOc2(TIM3, &TIM_OCInitStructure);
    TIM_ConfigOc2Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);
    /* PWM1 Mode configuration: Channel3 */
    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR3_Value;
    TIM_InitOc3(TIM3, &TIM_OCInitStructure);
    TIM_ConfigOc3Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);
    /* PWM1 Mode configuration: Channel4 */
    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR4_Value;
    TIM_InitOc4(TIM3, &TIM_OCInitStructure);
    TIM_ConfigOc4Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);

    TIM_ConfigArPreload(TIM3, ENABLE);

    /* TIM3 enable counter */
    TIM_Enable(TIM3, ENABLE);

}

运行测试

测试代码

N32L43x_PWM.rar (480.45 KB, 下载次数: 1)

2022-7-31 09:13 上传

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Jacktang

方波效果很好，说明PWM测试代码是正确的吧

lugl4313820

两个方波形状非常好，如果频率加高，会不会也一样？

805721366

lugl4313820 发表于 2022-8-14 22:06 两个方波形状非常好，如果频率加高，会不会也一样？

测试过，频率加快，输出波形也很好