STM32L486 enable LPUART1 with DMA - debugging

Question

I'm trying to enable LPUART1 to write/read traces and debug my code.
Im setting PC0/PC1 pin:
/*Configure GPIO pins : PC0 PC1 */
GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF8_LPUART1;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
Created the handlers:
UART_HandleTypeDef hlpuart1;
DMA_HandleTypeDef hdma_lpuart_tx;
DMA_HandleTypeDef hdma_lpuart_rx;
My init function. I call it from main.c:
/* LPUART1 init function */
void MX_LPUART1_UART_Init(void)
{
hlpuart1.Instance = LPUART1;
hlpuart1.Init.BaudRate = 115200;
hlpuart1.Init.WordLength = UART_WORDLENGTH_8B;
hlpuart1.Init.StopBits = UART_STOPBITS_1;
hlpuart1.Init.Parity = UART_PARITY_NONE;
hlpuart1.Init.Mode = UART_MODE_TX_RX;
hlpuart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
hlpuart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
hlpuart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&hlpuart1) != HAL_OK)
{
Error_Handler();
}
}
The function HAL_UART_Init:
/* USER CODE BEGIN LPUART1_MspInit 0 */
/* USER CODE END LPUART1_MspInit 0 */
/* LPUART1 clock enable */
__HAL_RCC_LPUART1_CLK_ENABLE();
__HAL_RCC_GPIOC_CLK_ENABLE();
/**LPUART1 GPIO Configuration
PC0 ------> LPUART1_RX
PC1 ------> LPUART1_TX
*/
GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF8_LPUART1;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
/* LPUART1 DMA Init */
/* LPUART_RX Init */
hdma_lpuart_rx.Instance = DMA2_Channel7;
hdma_lpuart_rx.Init.Request = DMA_REQUEST_4;
hdma_lpuart_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
hdma_lpuart_rx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_lpuart_rx.Init.MemInc = DMA_MINC_ENABLE;
hdma_lpuart_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_lpuart_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_lpuart_rx.Init.Mode = DMA_CIRCULAR;
hdma_lpuart_rx.Init.Priority = DMA_PRIORITY_LOW;
if (HAL_DMA_Init(&hdma_lpuart_rx) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(uartHandle,hdmarx,hdma_usart1_rx);
/* LPUART_TX Init */
hdma_lpuart_tx.Instance = DMA2_Channel6;
hdma_lpuart_tx.Init.Request = DMA_REQUEST_4;
hdma_lpuart_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_lpuart_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_lpuart_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_lpuart_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_lpuart_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_lpuart_tx.Init.Mode = DMA_NORMAL;
hdma_lpuart_tx.Init.Priority = DMA_PRIORITY_LOW;
if (HAL_DMA_Init(&hdma_lpuart_tx) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(uartHandle,hdmatx,hdma_lpuart_tx);
/* LPUART1 interrupt Init */
HAL_NVIC_SetPriority(LPUART1_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(LPUART1_IRQn);
I have set the NVIC LPUART1 at the end of the last code. I have enable too the DMA2 channel 6 and 7 interrupts:
/**
* Enable DMA controller clock
*/
void MX_DMA_Init(void)
{
/* DMA controller clock enable */
__HAL_RCC_DMA1_CLK_ENABLE();
__HAL_RCC_DMA2_CLK_ENABLE();
/* DMA interrupt init */
/* DMA1_Channel1_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);
/* DMA1_Channel2_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel2_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel2_IRQn);
/* DMA1_Channel4_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel4_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel4_IRQn);
/* DMA1_Channel5_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel5_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel5_IRQn);
/* DMA2_Channel1_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA2_Channel1_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA2_Channel1_IRQn);
/* DMA2_Channel2_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA2_Channel2_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA2_Channel2_IRQn);
/* DMA2_Channel6_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA2_Channel6_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA2_Channel6_IRQn);
/* DMA2_Channel7_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA2_Channel7_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA2_Channel7_IRQn);
}
In my main.c im trying to print something and it always return "HAL_OK":
HAL_UART_Transmit_DMA(&hlpuart1, (uint8_t *)'ACK\n', 5);
Inside the last function, we have set this callback:
/* Set the UART DMA transfer complete callback */
huart->hdmatx->XferCpltCallback = UART_DMATransmitCplt;
And inside this one, we have this callback:
HAL_UART_TxCpltCallback(huart);
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart) {
/* Set transmission flag: transfer complete */
BaseType_t xHigherPriorityTaskWoken = pdFALSE;
if(huart->Instance == USART1)
{
if(UART_TX_Acess != NULL)
{
xSemaphoreGiveFromISR(UART_TX_Acess, &xHigherPriorityTaskWoken); //Usart transmision complete
}
}
else if(huart->Instance == LPUART1)
{
modbus_tx_finish = 0;
}
portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
}
Everything seems to be fine coded but DMA2_Channel6_IRQHandler is jumping and and inside DMA IRQhandler an error appears:
/* Transfer Error Interrupt management **************************************/
But I cant understand why...

Answer 1

Ok I noticed the error. I was writting wrong the function to write. THis was the original:
HAL_UART_Transmit_DMA(&hlpuart1, (uint8_t *)'ACK\n', 5);
And this is the change:
HAL_UART_Transmit_DMA(&hlpuart1, (uint8_t *)"ACK\n", 5);