/* Function for transferring the SLIP end frame byte, 0xC0.  */
static uint32_t send_tx_byte_end(void)
/* Function for transferring the SLIP end frame byte, 0xC0.  */
static uint32_t send_tx_byte_end(void)
{
    uint32_t err_code = app_uart_put(APP_SLIP_END);
    if ((err_code == NRF_SUCCESS) && (m_tx_buffer_index == 0))
    {
        send_tx_byte = send_tx_byte_default;
    }
    return err_code;
}