/* BLYNK CONNECTION INSTRUCTION
  V1:HUMIDITY
  V0:TEMPERATURE
  V2:DUST
  V3:GAS
  V4:NOTICATION
  V5:
  V6:
  V7:
*/

#define BLYNK_TEMPLATE_ID "TMPL24XEWly-e"
#define BLYNK_TEMPLATE_NAME "AIR QUALITY MONITORING SYSTEM"
#define BLYNK_AUTH_TOKEN "4zLXiOu6ILZFkn1BYTnxINUusuS7npa7"

#define FAN       26
#define GLED       18
#define RLED       21
#define DUST       5
#define MQ7        33
#define DHTPIN     23
#define TESTP      35

#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
#include <LiquidCrystal_I2C.h>
#include <string.h> 
#include <DHT.h>

char auth[] = BLYNK_AUTH_TOKEN;
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

LiquidCrystal_I2C lcd(0x27,16,2);
DHT dht(DHTPIN, DHT22,15);

String alert1="",alert2="",alert3="",alert4="";
float coAmount,dustAmount,Humidity,Temperature;
const int maxTemperature=50,maxcoAmount=50,maxdustAmount=50;
String notification;

unsigned long duration;
unsigned long starttime;
unsigned long endtime;
unsigned long sampletime_ms = 30000;
unsigned long lowpulseoccupancy = 0;
float ratio = 0;
float concentration = 0;

void setup()
{
  lcd.init();                  
  lcd.backlight();
  loadingdisplay();
  dht.begin();
  Serial.begin(9600);
 
  pinMode(GLED,OUTPUT);
  pinMode(RLED,OUTPUT);
  pinMode(FAN,OUTPUT);
  digitalWrite(FAN,LOW);
 
  Blynk.begin(auth, ssid, pass);
  digitalWrite(GLED,HIGH);
  digitalWrite(RLED,LOW);
}

void loop()
{
 Blynk.run();
 checkCO();
 checkDust;
 tempHum();
 if(coAmount>maxcoAmount)
 {
   digitalWrite(GLED,LOW);
   digitalWrite(RLED,HIGH);
   digitalWrite(FAN,HIGH);
   notify("one");
   
 }
 else
 {
   digitalWrite(FAN,LOW);
 }
 if(dustAmount>maxdustAmount)
 {
   digitalWrite(GLED,LOW);
   digitalWrite(RLED,HIGH);
   digitalWrite(FAN,HIGH);
   notify("two");
   digitalWrite(FAN,HIGH);
 }
 else
 {
   digitalWrite(FAN,LOW);
 }
 if(Temperature>maxTemperature)
 {
   digitalWrite(GLED,LOW);
   digitalWrite(RLED,HIGH);
   digitalWrite(FAN,HIGH);
   notify("three");
 }
 else
 {
   digitalWrite(FAN,LOW);
 }
  digitalWrite(RLED,LOW);
  digitalWrite(GLED,HIGH);
  homedisplay();
  send_update();
}

/*
BLYNK_WRITE(V4)
{
  int data=param.asInt();
  if(data!= minTemperature)
  {
    minTemperature=data;
  }
}*/

void send_update() 
{     
  Blynk.virtualWrite(V0,Temperature);
  Blynk.virtualWrite(V4,notification);
  Blynk.virtualWrite(V2,dustAmount);
  Blynk.virtualWrite(V3,coAmount);
  delay(150);  
}

void loadingdisplay()
{
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("SMART AQ MONITOR"); 
  lcd.setCursor(0,1);
  lcd.print("SYSTEM STARTING."); 
  delay(3000);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("PLEASE WAIT");
  lcd.setCursor(0,1);
  for(int k=0;k<16;k++)
  {
    lcd.setCursor(k,1);
    lcd.print(".");
    delay(500);
  }
}

void homedisplay()
{
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("T:"); 
  lcd.print(Temperature,1);
  lcd.setCursor(7,0);
  lcd.print("H:"); 
  lcd.print(Humidity,1);
  lcd.setCursor(0,1);
  lcd.print("D:"); 
  lcd.print(dustAmount,1);
  lcd.setCursor(7,1);
  lcd.print("G:"); 
  lcd.print(coAmount,1);
  delay(500);
}

void alert_display(String textAlert)
{
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("EMERGENCY ALERT");
  lcd.setCursor(0,1);
  lcd.print(textAlert);
}

void checkDust()
{
  duration = pulseIn(DUST, LOW);
  lowpulseoccupancy += duration;
  endtime = millis();
  if ((endtime-starttime) > sampletime_ms)
  {
    ratio = (lowpulseoccupancy-endtime+starttime + sampletime_ms)/(sampletime_ms*10.0);  // Integer percentage 0=>100
    concentration = 1.1*pow(ratio,3)-3.8*pow(ratio,2)+520*ratio+0.62; // using spec sheet curve
    //dustAmount=concentration;
    dustAmount=map(analogRead(35),0,4095,0,100);
    Serial.print("lowpulseoccupancy:");
    Serial.print(lowpulseoccupancy);
    Serial.print("    ratio:");
    Serial.print(ratio);
    Serial.print("    DSM501A:");
    Serial.println(concentration);
    lowpulseoccupancy = 0;
    starttime = millis();
  }
}

void checkCO()
{
  int sensorValue = analogRead(MQ7);       // read analog input pin 0
  Serial.print(sensorValue/60, DEC);  // prints the value read
  coAmount=map(sensorValue,0,4095,0,100);
}

void notify(String code)
{
  if(code=="one")
  {
    alert_display("co GAS DETECTED");
    notification="DANGEROUS GAS DETECTED PLEASE MOVE AWAY";
    //ADD SOUND
  }
  if(code=="two")
  {
    alert_display(" DUST DETECTED ");
    notification="DANGEROUS DUST DETECTED PLEASE MOVE AWAY";
    //ADD SOUND
  }
  if(code=="three")
  {
    alert_display("HIGH TEMPERATURE");
    notification="HIGH TEMPERATURE DETECTED PLEASE MOVE AWAY";
    //ADD SOUND
  }
  delay(3000);
}

void tempHum()
{
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
     Serial.print("Temperature: ");
     Serial.print(t);
     Serial.print(" degrees Celcius Humidity: "); 
     Serial.print(h);
  Temperature=t;
  Humidity=h;
}