MapleFreeRTOS library for Maple platform to implement realtime FreeRTOS.
Also need change systick.c and systick.h in hardware\leaflabs\cores\maple folder
Blink example: 

#include 

int ledPin =  13;    // LED connected to digital pin 13

static void vLEDFlashTask( void *pvParameters ) {
    for(;;) {
        vTaskDelay( 2000 );
        digitalWrite( ledPin, HIGH );
        vTaskDelay( 200 );
        digitalWrite( ledPin, LOW );
    }
}

// The setup() method runs once, when the sketch starts
void setup()   {
  // initialize the digital pin as an output:
    pinMode(ledPin, OUTPUT);
    
    xTaskCreate(
        vLEDFlashTask,
        "LEDx",
        configMINIMAL_STACK_SIZE,
        NULL,
        tskIDLE_PRIORITY + 2,
        NULL
        );
    vTaskStartScheduler();
}

void loop()
{
    // Insert background code here
}