Solved
FreeRTOS + UART Strange Behavior
Hi, I'm trying to practice FreeRTOS with my STM32F769I-Eval kit.
I made two task with different priority and print global variable with semaphore.
When I run my code, terminal print decreased value every time.
I don't know why. Here is my code.
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MPU Configuration--------------------------------------------------------*/
MPU_Config();
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* USER CODE BEGIN RTOS_MUTEX */
/* add mutexes, ... */
/* USER CODE END RTOS_MUTEX */
/* Create the semaphores(s) */
/* definition and creation of mySemaphore */
osSemaphoreDef(mySemaphore);
mySemaphoreHandle = osSemaphoreCreate(osSemaphore(mySemaphore), 1);
/* USER CODE BEGIN RTOS_SEMAPHORES */
/* add semaphores, ... */
/* USER CODE END RTOS_SEMAPHORES */
/* USER CODE BEGIN RTOS_TIMERS */
/* start timers, add new ones, ... */
/* USER CODE END RTOS_TIMERS */
/* Create the queue(s) */
/* definition and creation of myQueue */
osMessageQDef(myQueue, 16, uint16_t);
myQueueHandle = osMessageCreate(osMessageQ(myQueue), NULL);
/* USER CODE BEGIN RTOS_QUEUES */
/* add queues, ... */
/* USER CODE END RTOS_QUEUES */
/* Create the thread(s) */
/* definition and creation of defaultTask */
// osThreadDef(defaultTask, StartDefaultTask, osPriorityNormal, 0, 128);
// defaultTaskHandle = osThreadCreate(osThread(defaultTask), NULL);
/* definition and creation of myTestTask01 */
osThreadDef(myTestTask01, StartTask02, osPriorityLow, 0, 128);
myTestTask01Handle = osThreadCreate(osThread(myTestTask01), (void *)mySemaphoreHandle);
/* definition and creation of myTestTask02 */
osThreadDef(myTestTask02, StartTask03, osPriorityIdle, 0, 128);
myTestTask02Handle = osThreadCreate(osThread(myTestTask02), (void *)mySemaphoreHandle);
/* USER CODE BEGIN RTOS_THREADS */
/* add threads, ... */
/* USER CODE END RTOS_THREADS */
/* Start scheduler */
osKernelStart();
/* We should never get here as control is now taken by the scheduler */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}void StartTask02(void const * argument)
{
/* USER CODE BEGIN StartTask02 */
char buf[256];
osSemaphoreId semaphore = (osSemaphoreId)argument;
/* Infinite loop */
for(;;)
{
if(semaphore != NULL)
{
if(osSemaphoreWait(semaphore, osWaitForever) == osOK)
{
sprintf(buf, "Task02! : %d\r\n", g_iCount);
HAL_UART_Transmit(&huart1, (uint8_t*)buf, strlen(buf), 100);
osSemaphoreRelease(semaphore);
}
osDelay(500);
}
}
/* USER CODE END StartTask02 */
}
/* USER CODE BEGIN Header_StartTask03 */
/**
* @brief Function implementing the myTestTask02 thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_StartTask03 */
void StartTask03(void const * argument)
{
/* USER CODE BEGIN StartTask03 */
char buf[256];
osSemaphoreId semaphore = (osSemaphoreId)argument;
/* Infinite loop */
for(;;)
{
if(semaphore != NULL)
{
if(osSemaphoreWait(semaphore, osWaitForever) == osOK)
{
sprintf(buf, "Task03! : %d\r\n", g_iCount);
HAL_UART_Transmit(&huart1, (uint8_t*)buf, strlen(buf), 100);
osSemaphoreRelease(semaphore);
}
osDelay(500);
}
}
/* USER CODE END StartTask03 */
}Please let me know why this starnge behavior happen.
Thanks.