5 STM32F103RC dac输出使能后系统调度异常。

发布于 2021-12-07 17:54:04 浏览：1534 订阅该版

硬件为stm32f103rct6 使用dac1（PA4）输出正弦波，波形正常但系统调度异常，msh无法输入输出，不再执行每秒一次的`rt_kprintf("flag main \n")`，（此时依然在正常输出正弦波），调用main中for循环前的语句1或语句2任一语句任务调度即可恢复正常，rtt版本为3.1.5  做过如下尝试
1.降低DMA触发定时器TIM2的频率。没有效果。
2.换TIM6触发。依然不行
请教一下大家可能会是什么原因导致的？

main中配置如下：
```c
int main(void)
{

rt_uint32_t re_mcp = 0;
    fal_init();
    FlashPartition = fal_partition_find("app");
    if (NULL == FlashPartition)
    {
        rt_kprintf("Can't find %s Fal partition!\n","app");
        return RT_ERROR;
    }
    bsp_InitUart();
    bsp_InitLed();
    OsTaskCreate();
    spi_init();//softspi初始化

/*dac 相关配置和初始化*/
    DacGpioInit();
    DacDmaInit();
    MX_TIM2_Init();
    DacInit();
    
    //HAL_TIM_Base_Stop(&htim2);    //语句1
    //HAL_DAC_Stop_DMA(&hdac,DAC_CHANNEL_1);//语句2
    for(;;)
    {
        rt_kprintf("flag main \n");
        rt_thread_mdelay(1000);
    }
    return RT_EOK;
}

void DacGpioInit()
{
    __HAL_RCC_GPIOD_CLK_ENABLE();
    __HAL_RCC_GPIOA_CLK_ENABLE();
}

void DacDmaInit()
{
    /* DMA controller clock enable */
    __HAL_RCC_DMA2_CLK_ENABLE();

/* DMA interrupt init */
    /* DMA2_Channel3_IRQn interrupt configuration */
    HAL_NVIC_SetPriority(DMA2_Channel3_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(DMA2_Channel3_IRQn);
}

void DacInit()
{
    uint32_t Idx;        //定义变量  dac用
    DAC_ChannelConfTypeDef sConfig = {0};
    hdac.Instance = DAC;
    
    if (HAL_DAC_Init(&hdac) != HAL_OK)
    {
        Error_Handler();
    }
    /** DAC channel OUT1 config
    */
    sConfig.DAC_Trigger = DAC_TRIGGER_T2_TRGO;//DAC_TRIGGER_T2_TRGO;
    sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
    if (HAL_DAC_ConfigChannel(&hdac, &sConfig, DAC_CHANNEL_1) != HAL_OK)
    {
        Error_Handler();
    }

for (Idx = 0; Idx <100; Idx++)
    {
        DualSine12bit[Idx] = (Sine12bit[Idx] << 16)+ (Sine12bit[Idx]);
    }

HAL_TIM_Base_Start(&htim2);
    HAL_DAC_Start_DMA(&hdac,DAC_CHANNEL_1,(uint32_t *)DualSine12bit,100,DAC_ALIGN_12B_R);
}

void MX_TIM2_Init(void)
{
    TIM_ClockConfigTypeDef sClockSourceConfig = {0};
    TIM_MasterConfigTypeDef sMasterConfig = {0};

htim2.Instance = TIM2;
    htim2.Init.Prescaler = 72;
    htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
    htim2.Init.Period = 100;
    htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
    htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
    if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
    {
        Error_Handler();
    }
    sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
    if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
    {
        Error_Handler();
    }
    sMasterConfig.MasterOutputTrigger = TIM_TRGO_UPDATE;
    sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
    if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
    {
        Error_Handler();
    }
}
```
![微信图片_20211207174948.jpg](https://oss-club.rt-thread.org/uploads/20211207/3714ff2c3808ae73670bc4a1940f5157.jpg.webp)