FreeRTOS task in a C++ class

Kernel
1

FreRTOS task in a C++ class

Context: Use with Arduino and ESP32

Purpose: Background loop for sampling analog input.

Note: Arduino loop is set as the lowest priority task. The code works fine

Question: Is it appropriate as a FreeRTOS point of vue and could this FreeRTOS usage be improved?

====== Class code (part of) ==========

void AIFreeRTOS::begin(int ADCpin, float ADCmin, float ADCmax, float EUvalueMin, float EUvalueMax, int pace, int priority, int core)
{		
  _taskPriority = priority;
  _taskCore     = core    ;	
  _ADCpace      = pace    ;
		
  startTask();	
}

void AIFreeRTOS::startTaskImpl(void* _this)
{
  static_cast<AIFreeRTOS*>(_this)->task();
}

void AIFreeRTOS::startTask(void)
{	
 xTaskCreatePinnedToCore(this->startTaskImpl, "Task", 2048, this, _taskPriority, NULL, _taskCore);
}

void AIFreeRTOS::task(void)
{	
  unsigned long locCount = 0UL;
  unsigned long locAccu  = 0UL;
	
  int locADCpace = this->getADCpace();
	
  for (;;)
    {	  	  
     switch(this->getCmd())
     {			
      case START_CONV:
        locAccu += this->read();      
        ++locCount;
      break;
			
      case STOP_CONV:
        this->setCount(locCount);
        this->setAccu(locAccu);
        this->setState(CONV_STOPPED);
      break;			
						
      case INIT_CONV:
        locCount = 0UL;
        locAccu  = 0UL;
        this->setState(CONV_INITIATED);
      break;						
    }
		
    vTaskDelay(pdMS_TO_TICKS(locADCpace));
   }
}

int AIFreeRTOS::read(void)
{
  return analogRead(_pin);
}

void AIFreeRTOS::setCount(unsigned long Count)
{	
  _count = Count;
}

void AIFreeRTOS::setAccu(unsigned long Accu)
{	
  _accu = Accu;
}

float AIFreeRTOS::EUValue(void)
{		
  setCmd(STOP_CONV);			
  while(getState() != CONV_STOPPED){};
				
  _rawADC = computeMeanRaw((float)_accu, (float)_count);	
		
  _EUValue = computeEUvalue(_rawADC);
	
  setCmd(INIT_CONV);
  while(getState() != CONV_INITIATED){};	
			
  setCmd(START_CONV);
	
  return _EUValue;
}

======== Arduino code (part of) ===========

#include "AIFreeRTOS.h"

AIFreeRTOS Anemometer;
AIFreeRTOS Radiation ;

void setup()
{ 

  */ Note tasks are at the same priority = 1 and running at 200 Hz (5 milllisecs) -> vTaskDelay(pdMS_TO_TICKS(locADCpace));
  Anemometer.begin(34, 662.5, 1593.8224, 0.0, 16.2, 5, 1, APP_CPU);

  Radiation.begin(39, 208.14, 2516.0, 0.0, 1200.0, 5, 1, APP_CPU);

  Anemometer.setCmd(START_CONV);

  Radiation.setCmd(START_CONV);
}
 
void loop()
{
  Anemometer.readEUValue();
  Radiation.readEUValue();  
  delay(1000);
}
2

What exactly is your question? Re using C++ with FreeRTOS: There is nothing whatsoever wrong with that, it has been done hundreds of times before. Great for encapsulation. I personally shy away from things like SEH in embedded, but some have done that successfully too.

Or are you looking for best coding practices with FreeRTOS tasks in C++? I am not aware of any; there is no one size fits all modelling technique for concurrent threads of execution.

3

Thanks for the answers.
Since this approach has no downside. I will continue to use it.