//Created by Barbu Vulc!
//FreeRTOS library for Arduino:
#include <Arduino_FreeRTOS.h>

//Define variables for HC-SR04:
#define echoPin 2  //Attach pin D2 Arduino to pin Echo of HC-SR04.
#define trigPin 3  //Attach pin D3 Arduino to pin Trig of HC-SR04.
long duration;     //Variable for the duration of sound wave travel.
int distance;      //Variable for the distance measurement.

//Define variables for photoresistor:
const int sensorMin = 0;   //Sensor minimum...
const int sensorMax = 500; //Sensor maximum...

//Variables for LEDs:
const int LED1 = 11, LED2 = 12;
//'LED1' is for HC-SR04 & 'LED2' is for photoresistor.

void setup() {
  //Serial communication:
  Serial.begin(9600);

  //LEDs' initialization:
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  
  //The created tasks!
  xTaskCreate(Task1, "HC-SR04 sensor", 100, NULL, 1, NULL);
  xTaskCreate(Task2, "Photoresistor", 100, NULL, 0, NULL);
  xTaskCreate(Task3, "Communication", 100, NULL, 2, NULL);
}

//Task for HC-SR04 sensor!
static void Task1(void* pvParameters) {
  while (1) {
    //Clears the trigPin condition
    digitalWrite(trigPin, LOW);  delay(100);
    //Sets the trigPin HIGH (ACTIVE) for 10 microseconds
    digitalWrite(trigPin, HIGH);  delay(100);
    digitalWrite(trigPin, LOW);
    //Reads the echoPin, returns the sound wave travel time in microseconds
    duration = pulseIn(echoPin, HIGH);
    //Calculating the distance
    distance = duration * 0.034 / 2; //Speed of sound wave divided by 2 (go and back)

    Serial.println("Distance: ");
    Serial.print(distance);
    Serial.println(" cm");
    digitalWrite(LED1, 1);  digitalWrite(LED2, 0);

    vTaskDelay(500 / portTICK_PERIOD_MS);
  }
}

//Task for photoresistor!
static void Task2(void* pvParameters) {
  while (1) {
    // read the sensor:
    int sensorReading = analogRead(A0);
    // map the sensor range to a range of four options:
    int range = map(sensorReading, sensorMin, sensorMax, 0, 3);

    Serial.println("Range: ");
    Serial.print(range);
    Serial.println(" lux \n");
    digitalWrite(LED1, 0);  digitalWrite(LED2, 1);

    vTaskDelay(1000 / portTICK_PERIOD_MS);
  }
}

//Task purely for serial communication!
static void Task3(void* pvParameters) {
  while (1) {
    Serial.println(F("HC-SR04 sensor - Task1"));
    Serial.println(F("Photoresistor - Task2"));
    vTaskDelay(4000 / portTICK_PERIOD_MS);
  }
}

void loop() {}