There is also the hypothetical issue of the non-atomic nature of :
if (a) {
a=false;
In theory one task could do the ‘if(a)’ then be descheduled.
Then the other task would run and also see that ‘a’ is true.
So now both tasks think they ‘own’ the serial port.
That’s unlikely to happen, but if you complex code with many instances of this type of non-atomic code, then you might start to encounter occasional, hard to explain, unexpected behaviour.

Other than that, a quick look over your code suggests to me that your home made mutual exclusion would work. However, using a mutex would stop one task from running when the other task was using the serial output. Whereas in your code both tasks would always be eligible for being run by the scheduler, which would waste some processing power.

I’d say, in summary, that your solution would be fine (with the addition of volatile for ‘a’) for this simple case. For more complex code it would be better, and make the purpose of the code more obvious, if you used the facilities provided by FreeRTOS to manage scheduling and mutual exclusion.

boolean a = true;

void Task1(void *parameter) {
for (;;) {
if (a) {
a=false;
Serial.println(“Task1: Logging from Task 1”);
vTaskDelay(1000 / portTICK_PERIOD_MS);
Serial.println(“Task1: End of log from Task 1”);
a=true;
}
vTaskDelay(5000 / portTICK_PERIOD_MS);
}
}

void Task2(void *parameter) {
for (;;) {
if (a) {
a=false;
Serial.println(“Task2: Logging from Task 2”);
vTaskDelay(800 / portTICK_PERIOD_MS);
Serial.println(“Task2: End of log from Task 2”);
a=true;
}
vTaskDelay(3000 / portTICK_PERIOD_MS);
}
}

void setup() {
Serial.begin(115200);
delay(1000);
Serial.println(“Starting FreeRTOS”);

xTaskCreatePinnedToCore(
Task1, // Task function
“Task1”, // Task name
3000, // Stack size
NULL, // Task parameters
1, // Priority
NULL, // Task handle
1 // Core ID
);

xTaskCreatePinnedToCore(
Task2, // Task function
“Task2”, // Task name
3000, // Stack size
NULL, // Task parameters
2, // Higher priority
NULL, // Task handle
1 // Core ID
);
}

void loop() {

}

Hi.
Yes, that’s a great application for FreeRTOS.

Regards,
Sara