Uart receiver pb

[kkhli.1]

 i have established communication with a BLDC (Brushless DC) controller. Initially, i send a message to the controller using the function void sendParameter(uint8_t parameter). Following this transmission, the BLDC controller is expected to respond with a frame. Although the transmission process appears to be functioning correctly, the receiver is not operating as expected. i have confirmed this issue using a logic analyzer. 

UART_HandleTypeDef huart1;

uint8_t buffer[10];

uint8_t senddata[4] = {0x66, 0x42, 0x00, 0xA8};

uint8_t transmitAllowed = 1;

-----------------------------------------------*/

void SystemClock_Config(void);

static void MX_GPIO_Init(void);

static void MX_USART1_UART_Init(void)

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)

{

    HAL_UART_Receive_IT(&huart1, buffer, 1);

}

void sendParameter(uint8_t parameter)

{

  HAL_UART_Transmit_IT(&huart1, senddata, 4);

HAL_Delay(100);

}

  */

int main(void)

{

  HAL_Init();

  SystemClock_Config();

  MX_GPIO_Init();

  MX_USART1_UART_Init();

  HAL_UART_Receive_IT(&huart1, buffer, 10);

  while (1)

  {

        readParameter(0x42);

  }

[kkhli.1]

in polling mode, the receiver works well but remains different from what I expect

[Karl Yamashita]

You're all over the map. First you post a screenshot that shows your buffer of 10 are all zeros and now you're showing a buffer of 14(?) with data.  

[kkhli.1]

no first is with interruption mode ..there is no data..but now i'm using polling mode

[Karl Yamashita]

Sorry, i missed that you wrote polling. 

Go back to interrupt mode. See if HAL_UART_ErrorCallback is called. If so, check the error code huart->ErrorCode

Here are the possible error codes

#define HAL_UART_ERROR_NONE 0x00000000U /*!< No error */

#define HAL_UART_ERROR_PE 0x00000001U /*!< Parity error */

#define HAL_UART_ERROR_NE 0x00000002U /*!< Noise error */

#define HAL_UART_ERROR_FE 0x00000004U /*!< Frame error */

#define HAL_UART_ERROR_ORE 0x00000008U /*!< Overrun error */

#define HAL_UART_ERROR_DMA 0x00000010U /*!< DMA transfer error */

[kkhli.1]

I looked with a LOgic to analyze the frame sent by stm32 and received by BLDC: I see that when I reduce the delay to 10 ms, I can receive data but not the exact expected frame

void sendParameter(uint8_t parameter)

{

  HAL_UART_Transmit_IT(&huart1, senddata, 4);

HAL_Delay(100);//reduce the delay to 10 ms, 

}

[kkhli.1 · Accepted solution]

HELLO,I resolved the problem and I want to share the solution with you: the issue is with the RX is always pulled down by the BLDC,, just I changed the brushless controller and all is ok

[Andrew Neil]

Thanks for sharing - be sure to also share this to your other threads about this problem.