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How to configure FREERTOS Tasks for the following description

Hi Everyone

My requirements are as follows

1. I am running 4 tasks using free rtos in which one measures the ADC , 2nd sends the adc data over BLE and 3rd check if the button is pressed or not and 4th sends the ADC data to LORA.

2. All my 4 tasks are running perfectly so far.

But i would like to have this feature in my code.

Whenever i press the button , the controller should come out of sleep mode and run the other 2 tasks of measuring adc and sending data over BLE.

As long as button is in low state(NOT PRESSED) ,the controller should remain in sleep mode and should not do anything.

My questions are

1. How to put the nrf52840 to Sleep mode ?

2. How to achieve the above described theory using FREERTOS Tasks.

3. Can i use mutexes and sempahores for the above theory?

4. What are the available Sleep modes on nrf52840.?

5. What are the functions to call to put nrf52840 to sleep modes?

Parents Reply Children
  • One more question I have, i.e is it necessary to have a while(1) inside the task function that we had called when created a task? Because I have to perform the above tasks using tasks also.

  • I am attaching my code snippet for your reference. I am not able to perform the tasks in sync that is first battery level reading task should be done and then stop and start ble advertising task but

    xSemaphoreHandle task_signal = 0;
    
    
    
    void Battery_Level_Take_Reading(void)
    {
      task_signal = xSemaphoreCreateBinary();
      uint32_t iteration = 0;
      while (1)
      {
         if( task_signal != NULL )
         {
            uint32_t i;
            for(iteration = 0;iteration <10;iteration++)
            {
              nrf_saadc_value_t result;
              uint32_t calc;
    
              if (nrfx_saadc_sample_convert(0, &result) != NRFX_SUCCESS)
              {
                NRF_LOG_INFO("ADC failure\r\n");
              }
              else
              {
               printf("ADC: %d\r\n", result);
          //      NRF_LOG_INFO("ADC: %d\r\n", result);
               }
                vTaskDelay(TASK_DELAY);
            }
         }
         xSemaphoreGive( task_signal );
      }
        
    }
    
    
    
    
    /**@brief Function for starting advertising.
     */
     void advertising_start(void)
    {
        ble_stack_init();
        gap_params_init();
        gatt_init();
        services_init();
        advertising_init();
        conn_params_init();
        while(1)
      {
        printf(" ble task 1 \n");
    //    if( task_signal != NULL )
        if(xSemaphoreTake(task_signal, portMAX_DELAY))
    
        {
          uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
          APP_ERROR_CHECK(err_code);
    
          vTaskDelay(15000);
          xSemaphoreGive(task_signal);
        }
       }
    }
    
    
    
    int main(void)
    {
        bool erase_bonds;
    
        // Initialize.
        log_init();
        timers_init();
        buttons_leds_init(&erase_bonds);
        power_management_init();
        
        saadc_init();
        saadc_sampling_event_enable();
    
      
        UNUSED_VARIABLE(xTaskCreate(Battery_Level_Take_Reading, "adc1", configMINIMAL_STACK_SIZE + 200, NULL, 2, &adc1_task_handle));
        UNUSED_VARIABLE(xTaskCreate(advertising_start, "ble", configMINIMAL_STACK_SIZE + 200, NULL, 1, &ble_task_handle));
    
    
        
    // Start FreeRTOS scheduler.
        vTaskStartScheduler();
        // Enter main loop.
        for (;;)
        {
            idle_state_handle();
        }
    }
    
    
    both the tasks are working together. What wrong am I doing?

  • https://www.freertos.org/a00130.html : To suspend a running task
    https://www.freertos.org/a00131.html : to resume the suspended task

    You can run the battery task and suspend the ble task and then when the measurement is done , you can suspend the battery task and resume the ble task

    Thanks

  • Thank you. Will implement the above in my code and will get back to you.

  • Hi,

     I used the task suspend and resume but with this I am only able to start the task of battery only once and then ble task does not start.

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