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。
使用STM32CubeMX的精简调试方案没有问题
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
*
* <h2><center>© Copyright (c) 2021 STMicroelectronics.
* All rights reserved.</center></h2>
*
* 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****/
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。
同样的代码在项目中无法运行
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:
- Set the
CR2_DDS bit, as in the accepted answer. However this might cause overrun error, as data is continuously converted. - Clear the
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。
