// Factory Environment Monitoring System
// Written by Jun Zhi Wong at Asia Pacific University for Assignment Purposes
// This code is designed to run on Arduino Mega2560, however it should run on other micro-controllers that support Arduino IDE

// Miscellaneous Libraries
#include <SPI.h>
#include <Wire.h>
#include <Arduino.h>
#include <Ewma.h>  // used for weighted average
#include <stdio.h>
#include <string.h>
#include <uRTCLib.h>  // used for RTC

// Include libraries for sensor
#include <MQUnifiedsensor.h>  // used for reading MQ sensors properly
#include <DHT.h>              // used for reading DHT sensor
#include <DHT_U.h>            // used for reading DHT sensor
#include <Adafruit_AHTX0.h>   // used for reading AHT20 sensor
#include <Adafruit_BMP280.h>  // used for reading BMP280 sensor

// Include libraries for user inputs/displays/outputs
#include <Adafruit_GFX.h>      // used for SSD1306 OLED display
#include <Adafruit_SSD1306.h>  // used for SSD1306 OLED display
#include <SD.h>                // used for SD card
#include <Keypad.h>

// Microcontroller ADC Specification
#define Voltage_Resolution 5
#define ADC_Bit_Resolution 10

// Port and Sensor Definitions
#define S_MQ2 A0
#define S_MQ3 A1
#define S_MQ7 A2
#define S_MQ8 A3
#define S_MQ9 A4
#define S_MQ135 A5
#define S_DHT11 44
#define S_Flame 42
#define S_Proximity 40
Adafruit_AHTX0 aht;
Adafruit_BMP280 bmp;  // use I2C interface
Adafruit_Sensor *bmp_temp = bmp.getTemperatureSensor();
Adafruit_Sensor *bmp_pressure = bmp.getPressureSensor();
#define buzzer 8

// Precalibrated clean air PPM value of each MQ series sensor
#define RatioMQ2CleanAir 8.34    // Clean air = 8.34 ppm
#define RatioMQ3CleanAir 1.10    // 1.10 ppm
#define RatioMQ7CleanAir 2.45    // 2.45 ppm
#define RatioMQ8CleanAir 1.27    // 1.27 ppm
#define RatioMQ9CleanAir 8.34    // 8.34 ppm
#define RatioMQ135CleanAir 1.10  // 1.10 ppm
#define DHTTYPE DHT11
#define placa "adc"

// Declare Sensor Objects
MQUnifiedsensor MQ2(placa, Voltage_Resolution, ADC_Bit_Resolution, S_MQ2, "MQ-2");
MQUnifiedsensor MQ3(placa, Voltage_Resolution, ADC_Bit_Resolution, S_MQ3, "MQ-3");
MQUnifiedsensor MQ7(placa, Voltage_Resolution, ADC_Bit_Resolution, S_MQ7, "MQ-7");
MQUnifiedsensor MQ8(placa, Voltage_Resolution, ADC_Bit_Resolution, S_MQ8, "MQ-8");
MQUnifiedsensor MQ9(placa, Voltage_Resolution, ADC_Bit_Resolution, S_MQ9, "MQ-9");
MQUnifiedsensor MQ135(placa, Voltage_Resolution, ADC_Bit_Resolution, S_MQ135, "MQ-135");
DHT_Unified dht(S_DHT11, DHTTYPE);

// Keypad Definitions
const char ROW = 4;  //four rows
const char COL = 4;  //four columns
char keys[ROW][COL] = {
  { 1, 2, 3, 10 },
  { 4, 5, 6, 11 },
  { 7, 8, 9, 12 },
  { 14, 0, 15, 13 }
};
byte rowPins[ROW] = { 22, 24, 26, 28 };  //connect to the row pinouts of the keypad
byte colPins[COL] = { 23, 25, 27, 29 };  //connect to the column pinouts of the keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROW, COL);

// OLED Definitions
#define SCREEN_WIDTH 128     // OLED display width, in pixels
#define SCREEN_HEIGHT 64     // OLED display height, in pixels
#define OLED_RESET -1        // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C  // Default 128x64 OLED screen I2C Address
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Miscellaneous Definitions
int counter = 0;
char showState, tempShowState;
File txtFile;
char filename[13];
char sensorValuesForWrite[11], RFID[10];  // temporary values before concatenating into output string
char outputString[120];                   // string output for logging or cloud platform
uRTCLib rtc(0x68);
char Time[25];                            // used for calibrating RTC
int TimeArray[7];                         // used for calibrating RTC

// Sensor Data
float MQ2Val, MQ3Val, MQ7Val, MQ8Val, MQ9Val, MQ135Val, tempAverage, humidAverage = 0;
sensors_event_t dht11Temp, dht11Humid, aht20Temp, aht20Humid, bmp280Temp, bmp280Pressure;
unsigned long sensorDelay, sendDelay, displayDelay = 0;  // time elapsed for sensor sensing and POST to cloud
Ewma MQ2Average(0.01);                     // Define weight for weighted average, 0.01 means new values have 1% significance
Ewma MQ3Average(0.01);
Ewma MQ7Average(0.01);
Ewma MQ8Average(0.01);
Ewma MQ9Average(0.01);
Ewma MQ135Average(0.01);
Ewma temperatureAverage(0.01);
Ewma humidityAverage(0.01);
Ewma airPressureAverage(0.01);
char hazardousEnvironment[11];  // array for storing hazardous environment data

void keypadEvent() {  // executes when keypad is pressed
  switch (keypad.getState()) {
    case PRESSED:
      showState = keypad.getKey();
      break;

    case HOLD:
      showState = keypad.getKey();
      break;
  }
}

void readUID() {  // read UID from security system
  if ((Serial3.available() > 0)) {
    Serial3.readBytesUntil('\n', RFID, 10);
    Serial3.flush();
  }
}

void readSensor() {
  MQ2.update();
  MQ3.update();
  MQ7.update();
  MQ8.update();
  MQ9.update();
  MQ135.update();
  MQ2Val = MQ2.readSensor();
  MQ3Val = MQ3.readSensor();
  MQ7Val = MQ7.readSensor();
  MQ8Val = MQ8.readSensor();
  MQ9Val = MQ9.readSensor();
  MQ135Val = MQ135.readSensor();
  dht.temperature().getEvent(&dht11Temp);
  dht.humidity().getEvent(&dht11Humid);
  aht.getEvent(&aht20Humid, &aht20Temp);
  bmp_temp->getEvent(&bmp280Temp);
  bmp_pressure->getEvent(&bmp280Pressure);
  tempAverage = (dht11Temp.temperature + aht20Temp.temperature + bmp280Temp.temperature) / 3;
  humidAverage = (dht11Humid.relative_humidity + aht20Humid.relative_humidity) / 2;
}

void writeToFile() {
  // add a new line to the buffer
  rtc.refresh();
  memset(outputString, 0, sizeof(outputString));
  // Format the date and time into the string
  sprintf(Time, "%02d%02d%02d%02d%02d%04d", rtc.hour(), rtc.minute(), rtc.second(), rtc.day(), rtc.month() + 1, rtc.year() + 1900);
  strcpy(outputString, Time);
  dtostrf(MQ2Val, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ3Val, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ7Val, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ8Val, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ9Val, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ135Val, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(tempAverage, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(humidAverage, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(bmp280Pressure.pressure, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  strncat(outputString, "|", 1);
  strncat(outputString, RFID, 9);
  strncat(outputString, "|", 1);
  strncat(outputString, hazardousEnvironment, 10);
  strncat(outputString, "\0", 1);
  txtFile.println(outputString);
  txtFile.flush();
}

void oledDisplay(unsigned long now) {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.setTextSize(1);
  display.setTextColor(WHITE);
  switch (showState) {
    case '1':
      {
        display.setTextSize(2);
        display.println("MQ2(LPG): ");
        display.print(MQ2Average.output);
        display.println(" PPM");
        break;
      }
    case '2':
      {
        display.setTextSize(2);
        display.println("MQ3(C2H60): ");
        display.print(MQ3Average.output);
        display.println(" PPM");
        break;
      }
    case '3':
      {
        display.setTextSize(2);
        display.println("MQ7(H2): ");
        display.print(MQ7Average.output);
        display.println(" PPM");
        break;
      }
    case '4':
      {
        display.setTextSize(2);
        display.println("MQ8(H2): ");
        display.print(MQ8Average.output);
        display.println(" PPM");
        break;
      }
    case '5':
      {
        display.setTextSize(2);
        display.println("MQ9(LPG): ");
        display.print(MQ9Average.output);
        display.println(" PPM");
        break;
      }
    case '6':
      {
        display.setTextSize(2);
        display.println("MQ135(C2H60): ");
        display.print(MQ135Average.output);
        display.println(" PPM");
        break;
      }
    case '7':
      {
        display.setTextSize(1);
        display.print("DHT11(°C): ");
        display.println(dht11Temp.temperature);
        display.print("DHT11(RH%): ");
        display.println(dht11Humid.relative_humidity);
        break;
      }
    case '8':
      {
        display.setTextSize(1);
        display.print("AHT20(°C): ");
        display.println(aht20Temp.temperature);
        display.print("AHT20(RH%): ");
        display.println(aht20Humid.relative_humidity);
        break;
      }
    case '9':
      {
        display.setTextSize(1);
        display.print("BMP280(°C): ");
        display.println(bmp280Temp.temperature);
        display.print("BMP280(atm): ");
        display.println(bmp280Pressure.pressure);
        break;
      }
    default:
      {
        if ((now - displayDelay) >= 2000) {
          display.print("MQ2(LPG):     ");
          display.println(MQ2Average.output);
          display.print("MQ3(C2H60):   ");
          display.println(MQ3Average.output);
          display.print("MQ7(H2):      ");
          display.println(MQ7Average.output);
          display.print("MQ8(H2):      ");
          display.println(MQ8Average.output);
          displayDelay = now;
        }
        else if ((now - displayDelay) >= 1000) {
          display.print("MQ9(LPG):     ");
          display.println(MQ9Average.output);
          display.print("MQ135(C2H60): ");
          display.println(MQ135Average.output);
          display.print("Temperature:  ");
          display.println(temperatureAverage.output);
          display.print("Humidity:     ");
          display.println(humidityAverage.output);
          display.print("Air Pressure: ");
          display.println(airPressureAverage.output);
        }
        break;
      }
  }
  display.display();
}

void transferToBlynk() {
  // Calculate Average
  MQ2Average.filter(MQ2Val);
  MQ3Average.filter(MQ3Val);
  MQ7Average.filter(MQ7Val);
  MQ8Average.filter(MQ8Val);
  MQ9Average.filter(MQ9Val);
  MQ135Average.filter(MQ135Val);
  temperatureAverage.filter(tempAverage);
  humidityAverage.filter(humidAverage);
  airPressureAverage.filter(bmp280Pressure.pressure);

  rtc.refresh();
  memset(outputString, 0, sizeof(outputString));
  // Format the date and time into the string
  sprintf(Time, "%02d%02d%02d%02d%02d%04d", rtc.hour(), rtc.minute(), rtc.second(), rtc.day(), rtc.month() + 1, rtc.year() + 1900);
  strcpy(outputString, Time);
  dtostrf(MQ2Average.output, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ3Average.output, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ7Average.output, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ8Average.output, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ9Average.output, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(MQ135Average.output, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(temperatureAverage.output, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(humidityAverage.output, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  dtostrf(airPressureAverage.output, 8, 2, sensorValuesForWrite);
  strncat(outputString, "|", 1);
  strncat(outputString, sensorValuesForWrite, strlen(sensorValuesForWrite));
  strncat(outputString, "|", 1);
  strncat(outputString, RFID, 9);
  strncat(outputString, "|", 1);
  strncat(outputString, hazardousEnvironment, 10);
  strncat(outputString, "\0", 1);
  Serial.println(outputString);
  memset(RFID, 48, 10);

  //Increment counter
  counter++;
  if (counter > 1000) { // This part is here to prevent overflow
    MQ2Average.reset();
    MQ3Average.reset();
    MQ7Average.reset();
    MQ8Average.reset();
    MQ9Average.reset();
    MQ135Average.reset();
    counter = 0;
  }
}

void getInternetTime() {
  // Default RTC address for DS3231
  URTCLIB_WIRE.begin();
  rtc.set_model(URTCLIB_MODEL_DS3231);
  while (1) {
    if (Serial.available() > 0) {
      TimeArray[6] = 0;
      Serial.readBytesUntil('\n', Time, 24); // Read internet time from ESP32
      char *token = strtok(Time, "|");
      int i = 0;
      // Split String
      while (token != NULL) {
        TimeArray[i] = atoi(token);
        i++;
        token = strtok(NULL, "|");
      }
      rtc.set(4, 11, 3, 3, 13, 11, 123);

      // Check if the values are valid, only proceed if valid (limit is year 2100)
      if (TimeArray[6] > 0 && TimeArray[6] < 200) {
        sprintf(filename, "%d%d%d.txt", 13, 11, (123 + 1900));
      }
      break;
    }
  }
}

void initSensors() {
  //Set math model to calculate the PPM concentration and the value of constants for MQ series sensor
  MQ2.setRegressionMethod(1);  //_PPM =  a*ratio^b
  MQ3.setRegressionMethod(1);
  MQ7.setRegressionMethod(1);
  MQ8.setRegressionMethod(1);
  MQ9.setRegressionMethod(1);
  MQ135.setRegressionMethod(1);

  // Configure the equation to calculate pollutant PPM
  MQ2.setA(574.25);
  MQ2.setB(-2.222);
  MQ3.setA(0.3934);
  MQ3.setB(-1.504);
  MQ7.setA(69.014);
  MQ7.setB(-1.374);
  MQ8.setA(976.97);
  MQ8.setB(-0.688);
  MQ9.setA(1000.5);
  MQ9.setB(-2.186);
  MQ135.setA(77.255);
  MQ135.setB(-3.18);  // Configure the equation to to calculate LPG concentration

  // Init Sensors
  MQ2.init();
  MQ3.init();
  MQ7.init();
  MQ8.init();
  MQ9.init();
  MQ135.init();
  dht.begin();
  aht.begin();
  bmp.begin();
}

void MQCalibrate() {  // Calibrates the sensor to match required base PPM using precalibrated data above
  // MQ2
  float calcR0 = 0;
  for (int i = 1; i <= 10; i++) {
    MQ2.update();  // Update data, the arduino will read the voltage from the analog pin
    calcR0 += MQ2.calibrate(RatioMQ2CleanAir);
  }
  MQ2.setR0(calcR0 / 10);
  // MQ3
  for (int i = 1; i <= 10; i++) {
    MQ3.update();  // Update data, the arduino will read the voltage from the analog pin
    calcR0 += MQ3.calibrate(RatioMQ3CleanAir);
  }
  MQ3.setR0(calcR0 / 10);
  // MQ7
  for (int i = 1; i <= 10; i++) {
    MQ7.update();  // Update data, the arduino will read the voltage from the analog pin
    calcR0 += MQ7.calibrate(RatioMQ7CleanAir);
  }
  MQ7.setR0(calcR0 / 10);
  // MQ8
  for (int i = 1; i <= 10; i++) {
    MQ8.update();  // Update data, the arduino will read the voltage from the analog pin
    calcR0 += MQ8.calibrate(RatioMQ8CleanAir);
  }
  MQ8.setR0(calcR0 / 10);
  // MQ9
  for (int i = 1; i <= 10; i++) {
    MQ9.update();  // Update data, the arduino will read the voltage from the analog pin
    calcR0 += MQ9.calibrate(RatioMQ9CleanAir);
  }
  MQ9.setR0(calcR0 / 10);
  // MQ135
  for (int i = 1; i <= 10; i++) {
    MQ135.update();  // Update data, the arduino will read the voltage from the analog pin
    calcR0 += MQ135.calibrate(RatioMQ135CleanAir);
  }
  MQ135.setR0(calcR0 / 10);
}

void setup() {
  pinMode(S_Flame, INPUT);
  pinMode(S_Proximity, INPUT);
  //Init the serial port communication, OLED screen and some variables
  Serial.begin(115200);  //Init serial port
  Serial3.begin(115200);
  display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);
  display.clearDisplay();
  memset(RFID, 48, 10);
  memset(hazardousEnvironment, 48, 10);

  // Initialise sensors and calibration
  initSensors();
  MQCalibrate();

  // Wait for ESP32 connect to internet and get time
  delay(5000);
  getInternetTime();
  if (!SD.begin()) {
    Serial.println("Card failed, or not present");
    // Don't do anything more
    while (1) {
      tone(buzzer, 2000);
    }
  }
  txtFile = SD.open(filename, FILE_WRITE);
  if (!txtFile) {
    Serial.print("error opening ");
    // Don't do anything more
    while (1) {
      tone(buzzer, 2000);
    }
  }

  // Interrupts 
  keypad.addEventListener(keypadEvent);  // Add an event listener for this keypad
  delay(1000);
}

void loop() {
  if ((Serial3.available() > 0)) { // Only read if something is available
    readUID();
  }

  if (digitalRead(S_Flame) == LOW) { // Check for fire
    hazardousEnvironment[7] = '1';
    Serial.println("Fire");
    tone(buzzer, 1000);
  } else if (digitalRead(S_Proximity) == HIGH) { // Check for obstacles on top of sensors
    Serial.println("Movement");
    tone(buzzer, 1000);
  } else {
    hazardousEnvironment[7] = '0';
    noTone(buzzer);
  }

  unsigned long now = millis();
  if ((now - sendDelay) >= 1000) { // Referesh display and POST data to cloud every second
    oledDisplay(now);
    transferToBlynk();
    sendDelay = now;
  }

  if ((now - sensorDelay) >= 250) { // Log sensor data every 250ms or 0.25s
    readSensor();
    writeToFile();
    sensorDelay = now;
  }
}

/*
Pin Table
MQ2 - A0
MQ3 - A1
MQ7 - A2
MQ8 - A3
MQ9 - A4
MQ135 - A5
DHT11 - D31
AHT20+BMP280 - I2C
Flame Sensor - D30
Buzzer - 8
OLED - I2C
SD Card - MOSI MISO 
          CLK: 51 
          CS: 52
Keypad - R: D22 D24 D26 D28
         C: D23 D25 D27 D29
         Interrupt: D33
ESP32 Connection - TX RX

********************************************  MQ Series Sensor Regression Table ********************************************
----------------- MQ2 -----------------
Most sensitive to LPG, Propane and Hydrogen
    Gas    | a      | b
    H2     | 987.99 | -2.162
    LPG    | 574.25 | -2.222
    CO     | 36974  | -3.109
    Alcohol| 3616.1 | -2.675
    Propane| 658.71 | -2.168
----------------- MQ3 -----------------
Most sensitive to Alcohol and Benzene 
    Gas    | a      | b
    LPG    | 44771  | -3.245
    CH4    | 2*10^31| 19.01
    CO     | 521853 | -3.821
    Alcohol| 0.3934 | -1.504
    Benzene| 4.8387 | -2.68
    Hexane | 7585.3 | -2.849
----------------- MQ7 -----------------
Most sensitive to Carbon Monoxide
    GAS     | a      | b
    H2      | 69.014  | -1.374
    LPG     | 700000000 | -7.703
    CH4     | 60000000000000 | -10.54
    CO      | 99.042 | -1.518
    Alcohol | 40000000000000000 | -12.35
----------------- MQ8 -----------------
Most sensitive to Hydrogen, Alcohol, and LPG are considered as noise
    GAS     | a      | b
    H2      | 976.97  | -0.688
    LPG     | 10000000 | -3.123
    CH4     | 80000000000000 | -6.666
    CO      | 2000000000000000000 | -8.074
    Alcohol | 76101 | -1.86
----------------- MQ9 -----------------
Most sensitive to Carbon Monoxide, Methane and Propane
    GAS     | a      | b
    LPG     | 1000.5 | -2.186
    CH4     | 4269.6 | -2.648
    CO      | 599.65 | -2.244
---------------- MQ135 ----------------
Most sensitive to NH3, Nitrogen Oxides, Alcohol, Benzene, smoke and CO2
    GAS      | a      | b
    CO       | 605.18 | -3.937  
    Alcohol  | 77.255 | -3.18 
    CO2      | 110.47 | -2.862
    Toluen  | 44.947 | -3.445
    NH4      | 102.2  | -2.473
    Aceton  | 34.668 | -3.369
---------------------------------------

---------------------------------------
*/