LAUNCHXL-CC1312R1: How to dynamically switch UART pin functions

You should not have to open and close the driver (I think). I took the uartExco example from the SDK, and added the following to toggle the TX pin a couple of times for each iteration, and that worked:

    while (1)
    {
        bytesRead = 0;
        while (bytesRead == 0)
        {
            status = UART2_read(uart, &input, 1, &bytesRead);

            if (status != UART2_STATUS_SUCCESS)
            {
                /* UART2_read() failed */
                while (1) {}
            }
        }

        bytesWritten = 0;
        while (bytesWritten == 0)
        {
            status = UART2_write(uart, &input, 1, &bytesWritten);

            if (status != UART2_STATUS_SUCCESS)
            {
                /* UART2_write() failed */
                while (1) {}
            }
        }

        GPIO_setConfigAndMux(CONFIG_GPIO_UART2_0_TX, GPIO_CFG_OUT_STD, IOC_PORT_GPIO);

        GPIO_write(CONFIG_GPIO_UART2_0_TX, 0);
        GPIO_write(CONFIG_GPIO_UART2_0_TX, 1);
        GPIO_write(CONFIG_GPIO_UART2_0_TX, 0);
        GPIO_write(CONFIG_GPIO_UART2_0_TX, 1);
        
        GPIO_setConfigAndMux(CONFIG_GPIO_UART2_0_TX, GPIO_CFG_OUT_STD, IOC_PORT_MCU_UART0_TX);
    }

Siri

Have you seen the following poast?

(+) CC1352R: TIRTOS usleep precision - Sub-1 GHz forum - Sub-1 GHz - TI E2E support forums

You can try to use the CPUdelay function:

//*****************************************************************************
//
//! \brief Provide a small non-zero delay using a simple loop counter.
//!
//! This function provides means for generating a constant length delay. It
//! is written in assembly to keep the delay consistent across tool chains,
//! avoiding the need to tune the delay based on the tool chain in use.
//!
//! \note It is not recommended using this function for long delays.
//!
//! Notice that interrupts can affect the delay if not manually disabled in advance.
//!
//! The delay depends on where code resides and the path for code fetching:
//! - Code in flash, cache enabled, prefetch enabled  : 4 cycles per loop (Default)
//! - Code in flash, cache enabled, prefetch disabled : 5 cycles per loop
//! - Code in flash, cache disabled                   : 7 cycles per loop
//! - Code in SRAM                                    : 6 cycles per loop
//! - Code in GPRAM                                   : 3 cycles per loop
//!
//! \note If using an RTOS, consider using RTOS provided delay functions because
//! these will not block task scheduling and will potentially save power.
//!
//! Calculate delay count based on the wanted delay in microseconds (us):
//! - ui32Count = [delay in us] * [CPU clock in MHz] / [cycles per loop]
//!
//! Example: 250 us delay with code in flash and with cache and prefetch enabled:
//! - ui32Count = 250 * 48 / 4 = 3000
//!
//! \param ui32Count is the number of delay loop iterations to perform. Number must be greater than zero.
//!
//! \return None
//
//*****************************************************************************
extern void CPUdelay(uint32_t ui32Count);

Also note that the GPIO_write function take a finite time to execute, so you woul need to compensate for this.

BR

Siri