// Include necessary libraries and headers
#include <Arduino.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"

// Define LED pin numbers
#define ledPin_Blue 2
#define ledPin_Red 3

// Declare a handle for the binary semaphore
SemaphoreHandle_t myBinarySemaphore;

// Setup function to initialize serial communication, pins, semaphore, and tasks
void setup() {
  // Begin serial communication at 9600 baud rate
  Serial.begin(9600);

  // Set LED pins as output
  pinMode(ledPin_Blue, OUTPUT);
  pinMode(ledPin_Red, OUTPUT);
  
  // Create a binary semaphore and immediately give it
  myBinarySemaphore = xSemaphoreCreateBinary();
  xSemaphoreGive(myBinarySemaphore);

  // Create two tasks with the same priority
  xTaskCreate(serialTask1, "serialTask1", 2000, NULL, 1, NULL);
  xTaskCreate(serialTask2, "serialTask2", 2000, NULL, 1, NULL);
}

// Task 1 function
void serialTask1(void * parameters){
  // Infinite loop
  for(;;){
    // Try to take the semaphore
    if (xSemaphoreTake(myBinarySemaphore, portMAX_DELAY)){
      // If successful, print a message, blink the blue LED, and give the semaphore back
      Serial.println("This is task 1");
      digitalWrite(ledPin_Blue, HIGH);
      vTaskDelay(250/portTICK_PERIOD_MS);
      digitalWrite(ledPin_Blue, LOW);
      vTaskDelay(250/portTICK_PERIOD_MS);
      xSemaphoreGive(myBinarySemaphore);
    }
  }
}

// Task 2 function
void serialTask2(void * parameters){
  // Infinite loop
  for(;;){
    // Try to take the semaphore
    if (xSemaphoreTake(myBinarySemaphore, portMAX_DELAY)){
      // If successful, print a message, blink the red LED, and give the semaphore back
      Serial.println("This is task 2");
      digitalWrite(ledPin_Red, HIGH);
      vTaskDelay(250/portTICK_PERIOD_MS);
      digitalWrite(ledPin_Red, LOW);
      vTaskDelay(250/portTICK_PERIOD_MS);
      xSemaphoreGive(myBinarySemaphore);
    }
  }
}

// Main loop function
void loop() {}