Why does the DMA gets out of sync when doing a sequence of regular AD conversions on stm32f103C8TX? This only happens with DMA_NORMAL.
It works with DMA_CIRCULAR (but I do not want or need continuous DMA transfers.)
You see by the terminal output below that reading 2 analog inputs works OK. However, after a while (< 1 minute) the 2 analog values are exchanged now. Apparently the DMA gets confused, but how and why I cannot understand.
Here is the code, all initialization was generated by STM32CubeMX, v5.5.0. (Had to omit part due to website restrictions on size of message.) NUM_AN_INPUTS=2
********** console output (about 30 seconds after swi upload / reset) ************
1959 0
1956 0
1957 0
1954 0
1955 0
1957 0
1955 0
1955 0
1954 0
1957 0
1959 0
0 1952
0 1953
3 1952
0 1952
0 1952
0 1953
0 1952
0 1953
********** usage of ADC in my code ************
volatile bool adc_done = false;
volatile uint16_t adc_buf[NUM_AN_INPUTS];
while(1) {
adc_done = false;
HAL_ADC_Start_DMA(&hadc1, (uint32_t*) adc_buf, NUM_AN_INPUTS);
while(!adc_done) {HAL_Delay(1);}
sprintf(message, "%d %d\n", adc_buf[0], adc_buf[1]);
serial.USBwrite(message);
HAL_Delay(100);
}
void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *) {
adc_done=true;
}
STMCubeMX Generated code and ADC calibration:
************ main.c: **************
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_DMA_Init();
MX_ADC1_Init();
MX_USB_DEVICE_Init();
MX_USART3_UART_Init();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
/* Run the ADC calibration */
if (HAL_ADCEx_Calibration_Start(&hadc1) != HAL_OK)
{
/* Calibration Error */
Error_Handler();
}
Init functions generated by STM32CubeMX
/**
* @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_ENABLE;
hadc1.Init.ContinuousConvMode = DISABLE;
hadc1.Init.DiscontinuousConvMode = DISABLE;
hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
hadc1.Init.NbrOfConversion = 2;
if (HAL_ADC_Init(&hadc1) != HAL_OK)
{
Error_Handler();
}
/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_8;
sConfig.Rank = ADC_REGULAR_RANK_1;
sConfig.SamplingTime = ADC_SAMPLETIME_28CYCLES_5;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}
/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_9;
sConfig.Rank = ADC_REGULAR_RANK_2;
sConfig.SamplingTime = ADC_SAMPLETIME_28CYCLES_5;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN ADC1_Init 2 */
/* USER CODE END ADC1_Init 2 */
}
/**
* 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);
}
STMCubeMX Generated code:
************ main.c: **************
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_GPIOB_CLK_ENABLE();
/**ADC1 GPIO Configuration
PB0 ------> ADC1_IN8
PB1 ------> ADC1_IN9
*/
GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
HAL_GPIO_Init(GPIOB, &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);
/* ADC1 interrupt Init */
HAL_NVIC_SetPriority(ADC1_2_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(ADC1_2_IRQn);
/* USER CODE BEGIN ADC1_MspInit 1 */
/* USER CODE END ADC1_MspInit 1 */
}
}
STMCubeMX Generated code:
************ stm32f1xx_hal_msp.c: **************
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_GPIOB_CLK_ENABLE();
/**ADC1 GPIO Configuration
PB0 ------> ADC1_IN8
PB1 ------> ADC1_IN9
*/
GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
HAL_GPIO_Init(GPIOB, &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);
/* ADC1 interrupt Init */
HAL_NVIC_SetPriority(ADC1_2_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(ADC1_2_IRQn);
/* USER CODE BEGIN ADC1_MspInit 1 */
/* USER CODE END ADC1_MspInit 1 */
}
}