Higher priority task that does not block

Kernel
1

Hello all,
I am currently using FreeRTOS kernel on a STM32f4, and I have the following problem:

  • I have three tasks and when they are of the same priority as TimerTask (configTIMER_TASK_PRIORITY), everything works correctly.

  • If I use a task of higher priority than TimerTask nothing starts, and when I increase the priority of TimerTask (same priority as the higher one), only the higher task works.

  • If I leave the same priority for all tasks, but that of TimerTask and higher, no task starts (it is as if it takes the cpu without freeing it).

NOTE: Knowing that the higher priority task and indeed blocks a good time to allow the activity of lower priority tasks.

My code is Here (working version):

#define configUSE_PREEMPTION                     1
#define configUSE_TIMERS                               1
#define configUSE_TIME_SLICING                    1
#define configTIMER_TASK_PRIORITY             2

void TaskBlue(void *pvParameters) {
   while (1) {
       blue_on();
       vTaskDelay(pdMS_TO_TICKS(5000)); 
   }
}

void TaskGreen(void *pvParameters) {
      while (1) {
       green_on();
       vTaskDelay(pdMS_TO_TICKS(1000));
   }
}

void TaskRed(void *pvParameters) {
    while (1) {
       red_on();
       vTaskDelay(pdMS_TO_TICKS(1000));
   }
}



void main_loop(void) {

clock_Init ();
timer_init();

SystemCoreClockUpdate();


if(SystemCoreClock != 168000000u){
    error();
    return;
}

SysTick_Config(SystemCoreClock / configTICK_RATE_HZ);


NVIC_SetPriority(SysTick_IRQn, configKERNEL_INTERRUPT_PRIORITY);

BaseType_t resultBlue =  xTaskCreate(TaskBlue, "Blue LED",   configMINIMAL_STACK_SIZE*2, NULL, 2, NULL);

BaseType_t resultGreen = xTaskCreate(TaskGreen, "Green LED", configMINIMAL_STACK_SIZE*2, NULL, 2, NULL);

BaseType_t resultRed =   xTaskCreate(TaskRed, "Red LED",     configMINIMAL_STACK_SIZE*2, NULL, 2, NULL);

if (resultBlue != pdPASS || resultGreen != pdPASS || resultRed != pdPASS) {
    error();
    return;
}

vTaskStartScheduler();

error();

for (;;);
}

Thank you by advance!

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