HAL_UART_Transmit_DMA

[Nandy K]

Posted on October 21, 2015 at 19:20

Hi,

I am using STM32F746.It is connected with ST wifi module(SPWF01SC) via UART./* Buffer used for transmission */uint8_t aTxBuffer[] = ''AT+S.SOCKD=8825\r\n'';/* Buffer used for reception */uint8_t aRxBuffer[RXBUFFERSIZE];In the program I am using HAL_UART_Transmit_DMA to transfer  and HAL_UART_Receive_DMA to receive.I am transmitting the buffer to start the wifi module and it is working fine.Now I am sending a string ''PIP'' from my wifi module.whenever I receive this string''PIP'' the MCU need to transmit back ''CIAO''.In my case I am receiving the string CIAO only when I reset the MCU and also it is working fine only for the first time after reset then for the second time i need to send the string twice then i get the response but after that there is no response.my main loop code :  UartHandle.Instance        = USARTx;  UartHandle.Init.BaudRate   = 115200;  UartHandle.Init.WordLength = UART_WORDLENGTH_8B;  UartHandle.Init.StopBits   = UART_STOPBITS_1;  UartHandle.Init.Parity     = UART_PARITY_NONE;  UartHandle.Init.HwFlowCtl  = UART_HWCONTROL_NONE;  UartHandle.Init.Mode       = UART_MODE_TX_RX;  if(HAL_UART_DeInit(&UartHandle) != HAL_OK)  {    Error_Handler();  }    if(HAL_UART_Init(&UartHandle) != HAL_OK)  {    Error_Handler();  }   if(HAL_UART_Transmit_DMA(&UartHandle, (uint8_t*)aTxBuffer, TXBUFFERSIZE)!= HAL_OK)  {    Error_Handler();  }   /*##-3- Wait for the end of the transfer ###################################*/    while (UartReady != SET)  {  } while (1)  {      HAL_Delay(100);          if(HAL_UART_Receive_DMA(&UartHandle, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)      {         // Error_Handler();      }           if(aRxBuffer[0]=='P'&&aRxBuffer[1]=='I'&&aRxBuffer[2]=='P')      {          aTxBuffer[0]='C';          aTxBuffer[1]='I';          aTxBuffer[2]='A';          aTxBuffer[3]='O';          aTxBuffer[4]='\r';          aTxBuffer[5]='\n';                     BSP_LED_On(LED1);           txBuf = 5;        if(HAL_UART_DeInit(&UartHandle) != HAL_OK)        {          Error_Handler();        }          if(HAL_UART_Init(&UartHandle) != HAL_OK)        {          Error_Handler();        }        if(HAL_UART_Transmit_DMA(&UartHandle, (uint8_t*)aTxBuffer, txBuf)!= HAL_OK)        {            //Error_Handler();        }                    while (UartReady != SET)        {                  }          aRxBuffer[0]='a';                 }            }Help me guys with some solution.my MCU need to reply back CIAO whenever I receive PIP on the UART.Please have a look at the image.