【国民技术车规MCU N32A455开发板】PWM方波产生测试

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【国民技术车规MCU N32A455开发板】PWM方波产生测试 [复制链接]

本周对于N32A455的PWM产生进行了测试，首先连接接线图如下：

 

使用的示波器为PicoScope的3205，利用电脑查看波形，将探头使用探针夹夹在PA6上，地与板子的GND连接，接下来将下列代码下载至板子上：

#include "main.h"

TIM_TimeBaseInitType TIM_TimeBaseStructure;
OCInitType TIM_OCInitStructure;
uint16_t CCR1_Val       = 333;
uint16_t CCR2_Val       = 249;
uint16_t CCR3_Val       = 166;
uint16_t CCR4_Val       = 83;
uint16_t PrescalerValue = 0;

void RCC_Configuration(void);
void GPIO_Configuration(void);


int main(void)
{
    RCC_Configuration();


    GPIO_Configuration();

    

    PrescalerValue = (uint16_t)(SystemCoreClock / 24000000) - 1;

    TIM_InitTimBaseStruct(&TIM_TimeBaseStructure);
    TIM_TimeBaseStructure.Period    = 665;
    TIM_TimeBaseStructure.Prescaler = PrescalerValue;
    TIM_TimeBaseStructure.ClkDiv    = 0;
    TIM_TimeBaseStructure.CntMode   = TIM_CNT_MODE_UP;

    TIM_InitTimeBase(TIM3, &TIM_TimeBaseStructure);


    TIM_InitOcStruct(&TIM_OCInitStructure);
    TIM_OCInitStructure.OcMode      = TIM_OCMODE_PWM1;
    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR1_Val;
    TIM_OCInitStructure.OcPolarity  = TIM_OC_POLARITY_HIGH;

    TIM_InitOc1(TIM3, &TIM_OCInitStructure);

    TIM_ConfigOc1Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);

    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR2_Val;

    TIM_InitOc2(TIM3, &TIM_OCInitStructure);

    TIM_ConfigOc2Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);

    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR3_Val;

    TIM_InitOc3(TIM3, &TIM_OCInitStructure);

    TIM_ConfigOc3Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);


    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR4_Val;

    TIM_InitOc4(TIM3, &TIM_OCInitStructure);

    TIM_ConfigOc4Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);

    TIM_ConfigArPreload(TIM3, ENABLE);

    TIM_Enable(TIM3, ENABLE);

    while (1)
    {
    }
}


void RCC_Configuration(void)
{
    RCC_EnableAPB1PeriphClk(RCC_APB1_PERIPH_TIM3, ENABLE);

    RCC_EnableAPB2PeriphClk(
        RCC_APB2_PERIPH_GPIOA | RCC_APB2_PERIPH_GPIOB | RCC_APB2_PERIPH_GPIOC | RCC_APB2_PERIPH_AFIO, ENABLE);
}


void GPIO_Configuration(void)
{
    GPIO_InitType GPIO_InitStructure;

    /* GPIOA Configuration:TIM3 Channel1, 2, 3 and 4 as alternate function push-pull */
    GPIO_InitStruct(&GPIO_InitStructure);
    GPIO_InitStructure.Pin        = GPIO_PIN_6 | GPIO_PIN_7;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_InitPeripheral(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.Pin = GPIO_PIN_0 | GPIO_PIN_1;
    GPIO_InitPeripheral(GPIOB, &GPIO_InitStructure);
}

#ifdef USE_FULL_ASSERT


void assert_failed(const uint8_t* expr, const uint8_t* file, uint32_t line)
{
   

    while (1)
    {
    }
}

#endif

该设置将PWM时钟设置为72MHz，PA6占空比为50%，PA7占空比为37.5%，PB0占空比为25%，PB1占空比为12.5%。相应波形如下：

PA6:

PA7:

PB0:

 

PB1:

 

可以看出按照相应地占空比输出了PWM波形。测试过程较为顺利。