#include <Arduino_FreeRTOS.h>
#include <task.h>

#define A_PIN (2)
#define B_PIN (3)
#define NUM_TASKS (4)

const int LED_PINS [] = {6,7,8,9}
TaskHandle_t  taskHandles[NUM_TASKS];
volatile int8_t counter = (NUM_TASKS-1);

void rotaryEncoderISR(){
  int8_t step = digitalRead(B_PIN) ? 1 : -1;
  counter = (NUM_TASKS + counter + step) % NUM_TASKS;
}

void task(void *param){
  uint8_t id = (uint8_t)param;
  pinMode(LED_PINS[id], OUTPUT);
}

void setup() {
  pinMode(A_PIN, INPUT_PULLUP); pinMode(B_PIN, INPUT_PULLUP);
  attachInterrupt( digitalPinToInterrupt(A_PIN), rotaryEncoderISR, FALLING );
  for (uint8_t i=0; i < NUM_TASKS; i++){
    xTaskCreate(task, "", 96, (uint8_t)i, 1, &taskHandles[i] );
  }
}


void loop(){
}