Hi Guys I am using the DMA with uart and get some problem.

[kevin xu]

i using the cubmx and generate the code.

I add the code in main function below ,(sur_dma_data[100] is arry and uint16_t size send i defined them before). but it is dose not work. can not see the any data from serilas port of my board . i check data with computer serials tools and also does not stop the brakerpoint at call back function. the DMA setings in cubmx are ok,

i set the breakpoint in call back function as below.

//*****within Mina()

 HAL_UART_Transmit_DMA(&huart1,sur_dma_data,size_send);

//********

if i write this code  HAL_UART_Transmit_IT(&huart1,Pdata,1); to replace above DMA. anything is ok - I can see data at serials tools and also the call back function is called.

// -------call backe function

 void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)

 {

//pro_counter++;

led_data=receive_data[0];

 }

//------------

any one can help me to settle the probelem ? thank you very much.

[KnarfB]

Did you add the USART1_TX DMA channel in STM32CubeMX Configuration > USART1 > DMA Settings?

[waclawek.jan]

Read out and check the relevant DMA and USART registers content.

JW

[kevin xu]

HI KnarfB

thank you for your help.

all the setings and configruations are ok, and these set by Cubmx. I find out the problem ready. the problem is the executed squence of the DMA _int and uart1_int. it should be DMA_int firstly then uart1_int, otherwise it is does not work with DMA.

it work

MX_DMA_Init();

MX_USART1_UART_Init();

it does not work

MX_USART1_UART_Init();

MX_DMA_Init();

[kevin xu]

Hi Waclawek

thank you for your help.

all the setings and configruations are ok, and these set by Cubmx. I find out the problem ready. the problem is the executed squence of the DMA _int and uart1_int. it should be DMA_int firstly then uart1_int, otherwise it is does not work with DMA.

it work

MX_DMA_Init();

MX_USART1_UART_Init();

it does not work

MX_USART1_UART_Init();

MX_DMA_Init();

[Amel NASRI]

Is your code initially generated with latest STM32CubeMX version (5.5)?