#include <Arduino.h>
#include <Arduino_FreeRTOS.h>
#include <semphr.h>

#define BUTTON_PIN 2  // Sử dụng chân 2 thay vì chân 1 do chân 1 và 0 được sử dụng cho Serial
#define LED_PIN 13

SemaphoreHandle_t binarySemaphore;

void LED_Task(void *pvParameters);
void buttonISR();

void setup() {
  Serial.begin(9600);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP); // Sử dụng PULLUP để tránh sử dụng thêm điện trở ngoài

  // Create the binary semaphore
  binarySemaphore = xSemaphoreCreateBinary();

  if (binarySemaphore == NULL) {
    Serial.println("Failed to create semaphore.");
    while (1); // Halt the program if semaphore creation fails
  }

  // Attach interrupt to the button pin
  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), buttonISR, FALLING);

  // Create task
  xTaskCreate(LED_Task, "LED Task", 128, NULL, 1, NULL);

  // Start scheduler
  vTaskStartScheduler();
}

void loop() {
  // Empty. Tasks are handled by FreeRTOS.
}

void LED_Task(void *pvParameters) {
  while (1) {
    // Wait for the semaphore
    if (xSemaphoreTake(binarySemaphore, portMAX_DELAY) == pdTRUE) {
      // Turn on the LED
      digitalWrite(LED_PIN, HIGH);
      Serial.println("LED is ON");
      
      // Wait for 1 second
      vTaskDelay(pdMS_TO_TICKS(1000));

      // Turn off the LED
      digitalWrite(LED_PIN, LOW);
      Serial.println("LED is OFF");
    }
  }
}

// Interrupt Service Routine (ISR)
void buttonISR() {
  BaseType_t xHigherPriorityTaskWoken = pdFALSE;

  // Give the semaphore
  xSemaphoreGiveFromISR(binarySemaphore, &xHigherPriorityTaskWoken);

  // Yield to higher priority task
  if (xHigherPriorityTaskWoken == pdTRUE) {
    portYIELD();
  }
}