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说明：这可能是STM32F4XX芯片的一个BUG。有些时候，单片机的问题非常奇怪，单一功能使用的时候没有问题，但同样的代码，在大型工程中漏洞百出；作为用户，我们无法知道芯片内部到底发生了什么，因为也只能一步步随机尝试。
问题：一个大型工程，在加入ADC的时候，发现HAL_ADC_Start_DMA始终只能触发一次，后续无论怎么Start，都没能成功。
在记录一下追踪的前因后果和解决方案。
在找问题的过程中，首先是用CubeMX创建一个工程调试一下。为了简洁，去掉几乎所有的功能，只开启了System core中的RCC/SYS，以及ADC要调试的8个通道。代码非常简洁，我全部贴在下面，
Main.c
在该文件中，大家只要看MX_ADC3_Init就够了，不过下面的代码中，有两个地方值得注意，
hadc3.Init.ContinuousConvMode = ENABLE; 这个在实际应用中要改为DISABLE。
hadc3.Init.DMAContinuousRequests = DISABLE; 这个一定要设置为DISABLE，否则开启一次后就会没完没了的采样，然后调用DMA中断，太耗资源了。本项目10mS左右采样一次，不需要这个。如下
#include "main.h"ADC_HandleTypeDef hadc3;DMA_HandleTypeDef hdma_adc3;void SystemClock_Config(void);static void MX_GPIO_Init(void);static void MX_DMA_Init(void);static void MX_ADC3_Init(void); uint32_t AD_DMA[8]; float AD_DMA_COPY[8]; int flag = 0; void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* AdcHandle){ //[i] Turn LED1 on: Transfer process is correct [/i]/ // BSP_LED_On(LED1); //HAL_GPIO_WritePin (GPIOF,GPIO_PIN_6,GPIO_PIN_SET ); AD_DMA_COPY[0] = (float)AD_DMA[0]; AD_DMA_COPY[1] = (float)AD_DMA[1]; AD_DMA_COPY[2] = (float)AD_DMA[2]; AD_DMA_COPY[3] = (float)AD_DMA[3]; AD_DMA_COPY[4] = (float)AD_DMA[4]; AD_DMA_COPY[5] = (float)AD_DMA[5]; AD_DMA_COPY[6] = (float)AD_DMA[6]; AD_DMA_COPY[7] = (float)AD_DMA[7];}int main(void){ uint8_t idx = 0; HAL_Init(); SystemClock_Config(); MX_GPIO_Init(); MX_DMA_Init(); MX_ADC3_Init(); while (1) { for(idx=0; idx<8;idx++){ AD_DMA_COPY[idx]=0; } if(flag) HAL_ADC_Start_DMA(&hadc3, AD_DMA, 8); HAL_Delay(1000); } }/** * @brief System Clock Configuration * @retval None */void SystemClock_Config(void){ RCC_OscInitTypeDef RCC_OscInitStruct = {0}; RCC_ClkInitTypeDef RCC_ClkInitStruct = {0}; /** Configure the main internal regulator output voltage */ __HAL_RCC_PWR_CLK_ENABLE(); __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1); /** Initializes the RCC Oscillators according to the specified parameters * in the RCC_OscInitTypeDef structure. */ RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE; RCC_OscInitStruct.HSEState = RCC_HSE_ON; RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON; RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE; RCC_OscInitStruct.PLL.PLLM = 8; RCC_OscInitStruct.PLL.PLLN = 336; RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2; RCC_OscInitStruct.PLL.PLLQ = 7; if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) { Error_Handler(); } /** Initializes the CPU, AHB and APB buses clocks */ RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2; RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4; RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2; if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK) { Error_Handler(); }}/** * @brief ADC3 Initialization Function * @param None * @retval None */static void MX_ADC3_Init(void){ ADC_ChannelConfTypeDef sConfig = {0}; hadc3.Instance = ADC3; hadc3.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV4; hadc3.Init.Resolution = ADC_RESOLUTION_12B; hadc3.Init.ScanConvMode = ENABLE; hadc3.Init.ContinuousConvMode = ENABLE; hadc3.Init.DiscontinuousConvMode = DISABLE; hadc3.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE; hadc3.Init.ExternalTrigConv = ADC_SOFTWARE_START; hadc3.Init.DataAlign = ADC_DATAALIGN_RIGHT; hadc3.Init.NbrOfConversion = 8; hadc3.Init.DMAContinuousRequests = DISABLE; hadc3.Init.EOCSelection = ADC_EOC_SEQ_CONV; if (HAL_ADC_Init(&hadc3) != HAL_OK) { Error_Handler(); } sConfig.Channel = ADC_CHANNEL_4; sConfig.Rank = 1; sConfig.SamplingTime = ADC_SAMPLETIME_3CYCLES; if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK) { Error_Handler(); } sConfig.Channel = ADC_CHANNEL_5; sConfig.Rank = 2; if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK) { Error_Handler(); } sConfig.Channel = ADC_CHANNEL_6; sConfig.Rank = 3; if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK) { Error_Handler(); } sConfig.Channel = ADC_CHANNEL_7; sConfig.Rank = 4; if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK) { Error_Handler(); } sConfig.Channel = ADC_CHANNEL_8; sConfig.Rank = 5; if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK) { Error_Handler(); } sConfig.Channel = ADC_CHANNEL_9; sConfig.Rank = 6; if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK) { Error_Handler(); } sConfig.Channel = ADC_CHANNEL_14; sConfig.Rank = 7; if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK) { Error_Handler(); } sConfig.Channel = ADC_CHANNEL_15; sConfig.Rank = 8; if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK) { Error_Handler(); } }static void MX_DMA_Init(void){ /* DMA controller clock enable */ __HAL_RCC_DMA2_CLK_ENABLE(); /* DMA interrupt init */ /* DMA2_Stream0_IRQn interrupt configuration */ HAL_NVIC_SetPriority(DMA2_Stream0_IRQn, 0, 0); HAL_NVIC_EnableIRQ(DMA2_Stream0_IRQn);}static void MX_GPIO_Init(void){ /* GPIO Ports Clock Enable */ __HAL_RCC_GPIOF_CLK_ENABLE(); __HAL_RCC_GPIOH_CLK_ENABLE(); __HAL_RCC_GPIOA_CLK_ENABLE(); __HAL_RCC_GPIOB_CLK_ENABLE(); stm32f4xx_hal_msp.c
该文件中，有用的只有一个函数HAL_ADC_MspInit，
/* USER CODE BEGIN Header *//** ****************************************************************************** * @file stm32f4xx_hal_msp.c * @brief This file provides code for the MSP Initialization * and de-Initialization codes. ****************************************************************************** * @attention * ** * This software component is licensed by ST under Ultimate Liberty license * SLA0044, the "License"; You may not use this file except in compliance with * the License. You may obtain a copy of the License at: * www.st.com/SLA0044 * ****************************************************************************** *//* USER CODE END Header *//* Includes ------------------------------------------------------------------*/#include "main.h"/* USER CODE BEGIN Includes *//* USER CODE END Includes */extern DMA_HandleTypeDef hdma_adc3;/* Private typedef -----------------------------------------------------------*//* USER CODE BEGIN TD *//* USER CODE END TD *//* Private define ------------------------------------------------------------*//* USER CODE BEGIN Define *//* USER CODE END Define *//* Private macro -------------------------------------------------------------*//* USER CODE BEGIN Macro *//* USER CODE END Macro *//* Private variables ---------------------------------------------------------*//* USER CODE BEGIN PV *//* USER CODE END PV *//* Private function prototypes -----------------------------------------------*//* USER CODE BEGIN PFP *//* USER CODE END PFP *//* External functions --------------------------------------------------------*//* USER CODE BEGIN ExternalFunctions *//* USER CODE END ExternalFunctions *//* USER CODE BEGIN 0 *//* USER CODE END 0 *//** * Initializes the Global MSP. */void HAL_MspInit(void){ /* USER CODE BEGIN MspInit 0 */ /* USER CODE END MspInit 0 */ __HAL_RCC_SYSCFG_CLK_ENABLE(); __HAL_RCC_PWR_CLK_ENABLE(); /* System interrupt init*/ /* USER CODE BEGIN MspInit 1 */ /* USER CODE END MspInit 1 */}/*** @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==ADC3) { /* USER CODE BEGIN ADC3_MspInit 0 */ /* USER CODE END ADC3_MspInit 0 */ /* Peripheral clock enable */ __HAL_RCC_ADC3_CLK_ENABLE(); __HAL_RCC_GPIOF_CLK_ENABLE(); /**ADC3 GPIO Configuration PF3 ------> ADC3_IN9 PF4 ------> ADC3_IN14 PF5 ------> ADC3_IN15 PF6 ------> ADC3_IN4 PF7 ------> ADC3_IN5 PF8 ------> ADC3_IN6 PF9 ------> ADC3_IN7 PF10 ------> ADC3_IN8 */ GPIO_InitStruct.Pin = GPIO_PIN_3|GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6 |GPIO_PIN_7|GPIO_PIN_8|GPIO_PIN_9|GPIO_PIN_10; GPIO_InitStruct.Mode = GPIO_MODE_ANALOG; GPIO_InitStruct.Pull = GPIO_NOPULL; HAL_GPIO_Init(GPIOF, &GPIO_InitStruct); /* ADC3 DMA Init */ /* ADC3 Init */ hdma_adc3.Instance = DMA2_Stream0; hdma_adc3.Init.Channel = DMA_CHANNEL_2; hdma_adc3.Init.Direction = DMA_PERIPH_TO_MEMORY; hdma_adc3.Init.PeriphInc = DMA_PINC_DISABLE; hdma_adc3.Init.MemInc = DMA_MINC_ENABLE; hdma_adc3.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD; hdma_adc3.Init.MemDataAlignment = DMA_MDATAALIGN_WORD; hdma_adc3.Init.Mode = DMA_CIRCULAR; hdma_adc3.Init.Priority = DMA_PRIORITY_LOW; hdma_adc3.Init.FIFOMode = DMA_FIFOMODE_DISABLE; if (HAL_DMA_Init(&hdma_adc3) != HAL_OK) { Error_Handler(); } __HAL_LINKDMA(hadc,DMA_Handle,hdma_adc3); /* USER CODE BEGIN ADC3_MspInit 1 */ /* USER CODE END ADC3_MspInit 1 */ }}/*** @brief ADC MSP De-Initialization* This function freeze the hardware resources used in this example* @param hadc: ADC handle pointer* @retval None*/void HAL_ADC_MspDeInit(ADC_HandleTypeDef* hadc){ if(hadc->Instance==ADC3) { /* USER CODE BEGIN ADC3_MspDeInit 0 */ /* USER CODE END ADC3_MspDeInit 0 */ /* Peripheral clock disable */ __HAL_RCC_ADC3_CLK_DISABLE(); /**ADC3 GPIO Configuration PF3 ------> ADC3_IN9 PF4 ------> ADC3_IN14 PF5 ------> ADC3_IN15 PF6 ------> ADC3_IN4 PF7 ------> ADC3_IN5 PF8 ------> ADC3_IN6 PF9 ------> ADC3_IN7 PF10 ------> ADC3_IN8 */ HAL_GPIO_DeInit(GPIOF, GPIO_PIN_3|GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6 |GPIO_PIN_7|GPIO_PIN_8|GPIO_PIN_9|GPIO_PIN_10); /* ADC3 DMA DeInit */ HAL_DMA_DeInit(hadc->DMA_Handle); /* USER CODE BEGIN ADC3_MspDeInit 1 */ /* USER CODE END ADC3_MspDeInit 1 */ }}/* USER CODE BEGIN 1 *//* USER CODE END 1 *//************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
© Copyright (c) 2021 STMicroelectronics. * All rights reserved.
然后是stm32f4xx_it.c，这里只有一句是有用的，就不贴全部代码了，
void DMA2_Stream0_IRQHandler(void){ /* USER CODE BEGIN DMA2_Stream0_IRQn 0 */ /* USER CODE END DMA2_Stream0_IRQn 0 */ HAL_DMA_IRQHandler(&hdma_adc3); /* USER CODE BEGIN DMA2_Stream0_IRQn 1 */ /* USER CODE END DMA2_Stream0_IRQn 1 */} 然后运行，结果没有问题。每启动一次HAL_ADC_Start_DMA，就会采样一次，然后会在HAL_ADC_ConvCpltCallback中看到结果。开启与采样一一对应。
我把同样的代码放到项目中去，发现运行根本没法和上面的一样，HAL_ADC_ConvCpltCallback只运行了一次，就死活没有第二次进入过。
因为我的工程太大了，完全去检查哪个的影响不太现实。反复调试后发现，如果在HAL_ADC_Start_DMA前，把ADC_CR2_DMA（第8位）清0，则能再次进入HAL_ADC_ConvCpltCallback函数。
无独有偶，我在这里
也发现了同样的讨论，直接摘录结果如下，I know it's late, but I'm going to put my answer here for other people's reference. I was using the STM HAL library and ran into this problem. The HAL library had the same bug as the code above.
To solve it, either:
CR2_DDS bit, as in the accepted answer. However this might cause overrun error, as data is continuously converted.CR2_DMA bit before setting it again (or call ADC_HAL_Start_DMA) to start the sampling again. This method should give you better control of when the sampling should be done.在我的代码中，我没有理会DDS位，只是简单地在HAL_ADC_Start_DMA前面添加了一句：
hadc3.Instance->CR2 &= ~ADC_CR2_DMA;
HAL_ADC_Start_DMA(&hadc3, ADC_ConvertedValue, g_def.NUM_ADC_CHANNELS);发现一切回归正常，和预设的一样，问题解决。
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