Uart Issue, FRDM-K64F

[ashishsingh0784]

Hi Community,

​Please help me for below issue.

​  Following line sending only first letter K  5 times.

  unsigned char str[] = "Kumar Rishi\r\n";

  UART_DRV_SendData(UART0_IDX, str, 5);

​Function:

​uart_status_t UART_DRV_SendData(uint32_t instance,                                const uint8_t * txBuff,

                                uint32_t txSize)

{

    assert(txBuff);

    assert(instance < UART_INSTANCE_COUNT);

    uart_status_t retVal = kStatus_UART_Success;

    uart_state_t * uartState = (uart_state_t *)g_uartStatePtr[instance];

    /* Indicates current transaction is non-blocking */

    uartState->isTxBlocking = false;

    /* Start the transmission process */

    retVal = UART_DRV_StartSendData(instance, txBuff, txSize);

    return retVal;   }

​static uart_status_t UART_DRV_StartSendData(uint32_t instance,                                            const uint8_t * txBuff,

                                            uint32_t txSize)

{

    assert(instance < UART_INSTANCE_COUNT);

    UART_Type * base = g_uartBase[instance];

    uart_state_t * uartState = (uart_state_t *)g_uartStatePtr[instance];

    /* Check that we're not busy already transmitting data from a previous

     * function call. */

    if (uartState->isTxBusy)

    {

        return kStatus_UART_TxBusy;

    }

    if (txSize == 0U)

    {

        return kStatus_UART_NoDataToDeal;

    }

    /* Initialize the module driver state structure. */

    uartState->txBuff = txBuff;

    uartState->txSize = txSize;

    uartState->isTxBusy = true;

    /* Enable the transmitter data register empty interrupt. The TDRE flag will

     * set whenever the TX buffer is emptied into the TX shift register (for

     * non-FIFO IPs) or when the data in the TX FIFO is at or below the

     * programmed watermark (for FIFO-supported IPs). */

    UART_BWR_C2_TIE(base, 1U);

    return kStatus_UART_Success;

}

[Jorge_Gonzalez]

Hello Ashish Singh:

Is your issue resolved?

As mentioned by Alice, you can use the KSDK UART example projects as starting point, either the blocking or non-blocking examples:

C:\Freescale\KSDK_1.3.0\examples\frdmk64f\driver_examples\uart

If you still face issues after checking the examples please share your project so I can have a look and see what you are missing.

Regards!

Jorge Gonzalez

[Alice_Yang]

Hello Singh,

I checked you use the KSDK.

Please use the function of "UART_DRV_SendDataBlocking" to send a sting .

A blocking (also known as synchronous) function means that the function does

not return until the transmit is complete.

While the function  UART_DRV_SendData  ,

    means that the function

* returns immediately after initiating the transmit function. The application

* has to get the transmit status to see when the transmit is complete. In

* other words, after calling non-blocking (asynchronous) send function, the

* application must get the transmit status to check if transmit is completed

* or not.

This meaning in the period of send data , if something else occur , the send will be some error,

for example some interrupt occur . So , please use the function of "UART_DRV_SendDataBlocking".

About the usage of this function , please refer to the demo code at here :

KSDK_1.3.0\examples\frdmk64f\driver_examples\uart\uart_blocking

Hope it helps

Have a great day,
Alice Yang

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