STM32F1与STM32CubeIDE快速入门-ADC通过DMA方式与PWM实现调光器

DMA 方法是以非常高的速率转换多个 ADC 通道的最有效方法，并且仍然将结果传输到内存而无需 CPU 干预，这是一种非常酷且省时的技术。
本次实例将实现ADC以DMA方式采样，并转换成PWM输出，从而达到调光效果。
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1、ADC的DMA方式配置

创建工程及系统时钟配置请参考前面文章，在这里不再做介绍。

1）ADC基本参数配置
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2）ADC的DMA配置
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3）定时器TIM2配置
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保存配置并生成代码。

2、代码生成与功能实现

STM32Cube IDE生成的主要代码如下：

1）ADC初始化

在main.c文件中

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/\*\*
 \* @brief ADC1 Initialization Function
 \* @param None
 \* @retval None
 \*/
static void MX\_ADC1\_Init(void) {

	/\* USER CODE BEGIN ADC1\_Init 0 \*/

	/\* USER CODE END ADC1\_Init 0 \*/

	ADC_ChannelConfTypeDef sConfig = { 0 };

	/\* USER CODE BEGIN ADC1\_Init 1 \*/

	/\* USER CODE END ADC1\_Init 1 \*/
	/\*\* Common config
 \*/
	hadc1.Instance = ADC1;
	hadc1.Init.ScanConvMode = ADC_SCAN_DISABLE;
	hadc1.Init.ContinuousConvMode = DISABLE;
	hadc1.Init.DiscontinuousConvMode = DISABLE;
	hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
	hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
	hadc1.Init.NbrOfConversion = 1;
	if (HAL\_ADC\_Init(&hadc1) != HAL_OK) {
		Error\_Handler();
	}
	/\*\* Configure Regular Channel
 \*/
	sConfig.Channel = ADC_CHANNEL_7;
	sConfig.Rank = ADC_REGULAR_RANK_1;
	sConfig.SamplingTime = ADC_SAMPLETIME_1CYCLE_5;
	if (HAL\_ADC\_ConfigChannel(&hadc1, &sConfig) != HAL_OK) {
		Error\_Handler();
	}
	/\* USER CODE BEGIN ADC1\_Init 2 \*/

	/\* USER CODE END ADC1\_Init 2 \*/

}

在stm32f1xx_hal_msp.c文件中：

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/\*\*
\* @brief ADC MSP Initialization
\* This function configures the hardware resources used in this example
\* @param hadc: ADC handle pointer
\* @retval None
\*/
void HAL\_ADC\_MspInit(ADC_HandleTypeDef\* hadc)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(hadc->Instance==ADC1)
  {
  /\* USER CODE BEGIN ADC1\_MspInit 0 \*/

  /\* USER CODE END ADC1\_MspInit 0 \*/
    /\* Peripheral clock enable \*/
    \_\_HAL\_RCC\_ADC1\_CLK\_ENABLE();

    \_\_HAL\_RCC\_GPIOA\_CLK\_ENABLE();
    /\*\*ADC1 GPIO Configuration
 PA7 ------> ADC1\_IN7
 \*/
    GPIO_InitStruct.Pin = GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
    HAL\_GPIO\_Init(GPIOA, &GPIO_InitStruct);

    /\* ADC1 DMA Init \*/
    /\* ADC1 Init \*/
    hdma_adc1.Instance = DMA1_Channel1;
    hdma_adc1.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_adc1.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_adc1.Init.MemInc = DMA_MINC_ENABLE;
    hdma_adc1.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
    hdma_adc1.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
    hdma_adc1.Init.Mode = DMA_NORMAL;
    hdma_adc1.Init.Priority = DMA_PRIORITY_LOW;
    if (HAL\_DMA\_Init(&hdma_adc1) != HAL_OK)
    {
      Error\_Handler();
    }

    \_\_HAL\_LINKDMA(hadc,DMA_Handle,hdma_adc1);

  /\* USER CODE BEGIN ADC1\_MspInit 1 \*/

  /\* USER CODE END ADC1\_MspInit 1 \*/
  }

}


2）DMA初始化

在main.c文件中

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/\*\*
 \* Enable DMA controller clock
 \*/
static void MX\_DMA\_Init(void) {

	/\* DMA controller clock enable \*/
	\_\_HAL\_RCC\_DMA1\_CLK\_ENABLE();

	/\* DMA interrupt init \*/
	/\* DMA1\_Channel1\_IRQn interrupt configuration \*/
	HAL\_NVIC\_SetPriority(DMA1_Channel1_IRQn, 0, 0);
	HAL\_NVIC\_EnableIRQ(DMA1_Channel1_IRQn);

}

3）定时器TIM2初始化

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/\*\*
 \* @brief TIM2 Initialization Function
 \* @param None
 \* @retval None
 \*/
static void MX\_TIM2\_Init(void) {

	/\* USER CODE BEGIN TIM2\_Init 0 \*/

	/\* USER CODE END TIM2\_Init 0 \*/

	TIM_ClockConfigTypeDef sClockSourceConfig = { 0 };
	TIM_MasterConfigTypeDef sMasterConfig = { 0 };
	TIM_OC_InitTypeDef sConfigOC = { 0 };

	/\* USER CODE BEGIN TIM2\_Init 1 \*/

	/\* USER CODE END TIM2\_Init 1 \*/
	htim2.Instance = TIM2;
	htim2.Init.Prescaler = 0;
	htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
	htim2.Init.Period = 65535;
	htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
	htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
	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();
	}
	if (HAL\_TIM\_PWM\_Init(&htim2) != HAL_OK) {
		Error\_Handler();
	}
	sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
	sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
	if (HAL\_TIMEx\_MasterConfigSynchronization(&htim2, &sMasterConfig)
			!= HAL_OK) {
		Error\_Handler();
	}
	sConfigOC.OCMode = TIM_OCMODE_PWM1;
	sConfigOC.Pulse = 0;
	sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
	sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
	if (HAL\_TIM\_PWM\_ConfigChannel(&htim2, &sConfigOC, TIM_CHANNEL_1)
			!= HAL_OK) {
		Error\_Handler();
	}
	/\* USER CODE BEGIN TIM2\_Init 2 \*/

	/\* USER CODE END TIM2\_Init 2 \*/
	HAL\_TIM\_MspPostInit(&htim2);

}


4）DMA中断及功能实现

在stm32f1xx_it.c文件中

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/\* Private variables ---------------------------------------------------------\*/
/\* USER CODE BEGIN PV \*/
extern uint16_t AD_RES;
/\* USER CODE END PV \*/

/\*\*
 \* @brief This function handles DMA1 channel1 global interrupt.
 \*/
void DMA1\_Channel1\_IRQHandler(void) {
	/\* USER CODE BEGIN DMA1\_Channel1\_IRQn 0 \*/

	/\* USER CODE END DMA1\_Channel1\_IRQn 0 \*/
	HAL\_DMA\_IRQHandler(&hdma_adc1);
	/\* USER CODE BEGIN DMA1\_Channel1\_IRQn 1 \*/

	/\* USER CODE END DMA1\_Channel1\_IRQn 1 \*/
}

/\* USER CODE BEGIN 1 \*/
void HAL\_ADC\_ConvCpltCallback(ADC_HandleTypeDef \*hadc) {
	// Conversion Complete & DMA Transfer Complete As Well
	// So The AD\_RES Is Now Updated & Let's Move IT To The PWM CCR1
	// Update The PWM Duty Cycle With Latest ADC Conversion Result
	TIM2->CCR1 = (AD_RES << 4);
}

5）程序入口及功能实现

在main.c文件中

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/\* Private typedef -----------------------------------------------------------\*/
/\* USER CODE BEGIN PTD \*/
uint16_t AD_RES = 0;
/\* USER CODE END PTD \*/

/\*\*
 \* @brief The application entry point.
 \* @retval int
 \*/
int main(void) {
	/\* USER CODE BEGIN 1 \*/

	/\* USER CODE END 1 \*/

	/\* MCU Configuration--------------------------------------------------------\*/

	/\* Reset of all peripherals, Initializes the Flash interface and the Systick. \*/
	HAL\_Init();

	/\* USER CODE BEGIN Init \*/

	/\* USER CODE END Init \*/

	/\* Configure the system clock \*/
	SystemClock\_Config();

	/\* USER CODE BEGIN SysInit \*/

	/\* USER CODE END SysInit \*/

	/\* Initialize all configured peripherals \*/
	MX\_GPIO\_Init();
	MX\_DMA\_Init();
	MX\_ADC1\_Init();
	MX\_TIM2\_Init();
	/\* USER CODE BEGIN 2 \*/
	HAL\_TIM\_PWM\_Start(&htim2, TIM_CHANNEL_1);
	// Calibrate The ADC On Power-Up For Better Accuracy
	HAL\_ADCEx\_Calibration\_Start(&hadc1);
	/\* USER CODE END 2 \*/

	/\* Infinite loop \*/
	/\* USER CODE BEGIN WHILE \*/
	while (1) {
		/\* USER CODE END WHILE \*/

		/\* USER CODE BEGIN 3 \*/
		// Start ADC Conversion
		// Pass (The ADC Instance, Result Buffer Address, Buffer Length)
		HAL\_ADC\_Start\_DMA(&hadc1, &AD_RES, 1);
		HAL\_Delay(1);
	}
	/\* USER CODE END 3 \*/
}

文章来源: https://iotsmart.blog.csdn.net/article/details/123496094