stm32F103 uart2 Tx dma transmission doesn't Works corretly

[NToua.2461]

I am using the stm32f103 and trying to display a text on a screen via DMA to the USART 2 device. I guess I will turn on the usart2 TX dma (DMAT) request when I need it and turn it off after the current transmission is complete (i.e. in the DMA1_Channel7_IRQHandler). That is, when I call the write_data_voltage_to_nextion(DEFINED IN MY CODE) USART2 DMATx function is enabled and DMA1 will serve it, same thing when I call the write_data_current_to_nextion(DEFINED IN MY CODE) USART2 DMAT function is enabled and DMA1 will serve it. The problem is that the display is correct when I execute one of two functions but if I execute the two functions successively nothing is displayed. The DMA1_Channel7_IRQHandler is not served after all.

I spent a lot of time on this problem, but I couldn't get it to work. Somebody help me, thank you. Here's my code...

uint32_t bff[40] = {'\0'};

void DMA1_USART2_TX_Config(void)

{

DMA_DeInit(DMA1_Channel7);

  RCC-> APB2ENR |= RCC_APB2ENR_AFIOEN;

  RCC-> APB2RSTR =0;

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

/* DMA */

DMA_InitTypeDef DMA_InitStruct;

DMA_InitStruct.DMA_PeripheralBaseAddr = (uint32_t)(&(USART2->DR));

DMA_InitStruct.DMA_MemoryBaseAddr = (uint32_t)&bff[0];

DMA_InitStruct.DMA_DIR = DMA_DIR_PeripheralDST;

DMA_InitStruct.DMA_BufferSize = sizeof(bff);

DMA_InitStruct.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

DMA_InitStruct.DMA_MemoryInc = DMA_MemoryInc_Enable;

DMA_InitStruct.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;

DMA_InitStruct.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;

DMA_InitStruct.DMA_Mode = DMA_Mode_Normal;

DMA_InitStruct.DMA_Priority =DMA_Priority_Low;// DMA_Priority_High;// DMA_Priority_VeryHigh;

DMA_InitStruct.DMA_M2M = DMA_M2M_Disable;

DMA_Init(DMA1_Channel7, &DMA_InitStruct);

USART_DMACmd(USART2, USART_DMAReq_Tx, ENABLE);

DMA_ITConfig( DMA1_Channel7,DMA_IT_TC,ENABLE );

DMA_Cmd(DMA1_Channel7, DISABLE);

NVIC_EnableIRQ(DMA1_Channel7_IRQn);

}

void DMA1_Channel7_IRQHandler(void)//TX

{

if(DMA_GetITStatus(DMA1_IT_TC7))

{

DMA_ClearITPendingBit(DMA1_IT_GL7);

DMA_Cmd(DMA1_Channel7, DISABLE);

}

}

void Nextion_usart_DMA(uint8_t *data, uint32_t data_len)/**uint16_t**/

{

memcpy(bff , data, data_len);

/* Restart DMA Channel*/

DMA_ITConfig(DMA1_Channel7, DMA_IT_TC, DISABLE);

USART_DMACmd(USART2, USART_DMAReq_Tx, DISABLE);

DMA_Cmd(DMA1_Channel7, DISABLE);

DMA1_Channel7->CNDTR = data_len;

DMA_ITConfig(DMA1_Channel7, DMA_IT_TC, ENABLE);

USART_DMACmd(USART2, USART_DMAReq_Tx, ENABLE);

DMA_Cmd(DMA1_Channel7, ENABLE);

}

void write_data_courant_to_nextion(float data) /*principale*/

{

  float_to_string(data,i_buf,Get_float_len(&data),3);

nextion_usart_DMA(I_T2_CONTROL_TYPE);

}

void write_data_voltage_to_nextion(float data) /*principale*/

{

float_to_string(data,v_buf,Get_float_len(&data),3);

nextion_DMA(V_T0_CONTROL_TYPE);

}

[Tesla DeLorean]

Code doesn't even look to be compilable, or consistent​.

Doesn't check if DMA is active.​

[NToua.2461]

clive I would like to make two transmissions in a row like the following.

1. void send_all_registers()

{

write_data_voltage_to_nextion(value_tension ) ;

write_data_courant_to_nextion(value_courant) ;

}

When I am under the debugger, we observe the first successful transmission, but the second transmission fails,

the problem is that the DMA1_Channel7_IRQHandler() function is not called between the two transmissions. I do not understand why. Do you know why ?