RTOS/CC2640R2F: Software serial scif driver API's not working when called from within other tasks

-There is currently one hardware UART which I am using for debug logs. Need an extra UART for interfacing some external device, the reason why I want use this.

- Yes. But doesn't really show how I can call the scif API's such as for example: scifUartTxPutChars( ) from within another task that is running on the main processor and not on the SC.

- The same code generated by the SCS with slight changes. Here you go. In the above code, I just showed an example of how I am calling the Tx  API from within another task to send some bytes which doesn't seem to be working. But when called within the below task i.e. sensor controller task, it works. I'd like to get it to work when called from other tasks as well.

/****************************************************************
 * Function Name : SerialSoftware_taskFxn
 * Description   : Enables sending and receiving bytes
 * Returns       : None
 * Params        : Task aruguements
 ****************************************************************/
void SerialSoftware_taskFxn(UArg a0, UArg a1) {

    /* Initialize the Sensor Controller */
    scifOsalInit();
    scifOsalRegisterCtrlReadyCallback(scCtrlReadyCallback);
    scifOsalRegisterTaskAlertCallback(scTaskAlertCallback);
    scifInit(&scifDriverSetup);

    /* Start the UART emulator */
    scifExecuteTasksOnceNbl(BV(SCIF_UART_EMULATOR_TASK_ID));

    /* Enable baud rate generation */
    scifUartSetBaudRate(57600);

    /* Enable RX (10 idle bit periods required before enabling start bit detection) */
    scifUartSetRxFifoThr(SCIF_UART_RX_FIFO_MAX_COUNT / 2);
    scifUartSetRxTimeout(10 * 2);
    scifUartSetRxEnableReqIdleCount(10 * 2);
    scifUartRxEnable(1);

    /* Enable events (half full RX FIFO or 10 bit period timeout */
    scifUartSetEventMask(BV_SCIF_UART_ALERT_RX_FIFO_ABOVE_THR | BV_SCIF_UART_ALERT_RX_BYTE_TIMEOUT);

    while (1)
    {

        /* Wait for an ALERT callback */
        bool gotBytes = Semaphore_pend(Semaphore_handle(&semScTaskAlert), 100);
       
        /* Looks like we received something - handle it */
        if(gotBytes)
        {
            /* Clear the ALERT interrupt source */
            scifClearAlertIntSource();

            /* Add code to handle the Rx Bytes */

            /* Clear the events that triggered this */
            scifUartClearEvents();

            /* Acknowledge the alert event */
            scifAckAlertEvents();
        }
        else
        {
            /* Do Nothing------>*/
        }
    }
}

Yes I need to access the software UART from just one another task i.e. User_taskFxn, running on the main processor. By sharing same resources I believe you mean the software serial API's that access the data structures. Sorry if I misunderstood something, still getting a hang on the RTOS.

From my understanding, we can use a semaphore to control access to the shared resource. Haven't used one until now and if given some insights on how to go about using it in this context, I'd be happy to use it to achieve the above.

In the example, calling the API in an infinite loop blocks the resources makes sense. But the question is, what If change that example to as below, will it work? I checked by probing the tx line and it doesn't. Just a one time entry call.

static void User_taskFxn(UArg a0, UArg a1)
{
    /* One time call - Should this work? */
    scifUartTxPutChars(txBuff, len);

    while(1)
    {
        
    }
}

Also, in the case I call scifUartTxPutChars( ) within the sensor controller task which does work, how does one know when all the bytes has been pumped out of the TX bus? I don't see any events or callbacks generated to notify that.

Okay, it makes sense now.

I actually don't need two tasks accessing the UART. I want to access the UART from only the User_taskFxn. I was confused to thinking that the tirtos main code containing a task generated by the SCS(I changed  its name to SerialSoftware_taskFxn)  also run on the SCE MCU and misunderstood that we need this task to be running at all times for us to actually access the UART emulator.

To solve the above problem and since the resource can only be used in one task per project, I will now just get rid of the SerialSoftware_taskFxn( ) task and move the SCE MCU init code and related code to the User_taskFxn( ) and will be then successfully able to access the UART emulator from within the  User_taskFxn( ). I will try this and believe it should work.

scifUartTxPutChars blocking sounds good to me.