Refrigerator Monitoring System

// Date: 04/19/2023
// By NSZ, SH, & RJ
// See HC-SR04 Ultrasonic Sensor tutorial below
// https://www.hackster.io/abdularbi17/ultrasonic-sensor-hc-sr04-with-arduino-tutorial-327ff6
//--------------------- ThingSpeak --------------------------------
#include <ThingSpeak.h>
TCPClient client;
// Temperature, Potentiometer, & Ultrasonic Measurements Channel number and API keys
unsigned long NealChannelNumber_T_P_U = 2086340;           // Neal's Channel Number
unsigned long SethChannelNumber_T_P_U = 2106700;           // Seth's Channel Number
unsigned long RahulChannelNumber_T_P_U = 2106709;          // Rahul's Channel Number
const char * NealWriteAPIKey_T_P_U = "IOZDUH8K2IIA9OQL";   // Neal's Channel Write API key
const char * SethWriteAPIKey_T_P_U = "8WH10SAHTEPVZPVK";   // Seth's Channel Write API key
const char * RahulWriteAPIKey_T_P_U = "0PE5S564WUZNZBSS";  // Rahul's Channel Write API key
//--------------------- LCD Screen --------------------------------
#include <LiquidCrystal.h>
LiquidCrystal lcd(D3, D4, D5, D6, D7, D8);// initialize library w/ the interface pins
//----------------- Temperature Sensor ----------------------------
#include "Adafruit_DHT_Particle.h"
#define DHTPIN A1                  // DHT11 Output Pin
#define DHTTYPE DHT11	           // Reference the DHT 11 Sensor from library
DHT dht(DHTPIN, DHTTYPE);
//------- Photoresistor (Light Dependent Resistor) Sensor ---------
#define PHOPIN A4                  // Photoresistor Output Pin
// Photoresistor Specs: Dark Resistance > 20M Ohms & Light Resistance < 80 Ohms
//----------------- Ultrasonic Sensor -----------------------------
#define echoPin A3 // attach Argon port pin A3 to pin Echo of HC-SR04
#define trigPin A2 // attach Argon port pin A2 to pin Trig of HC-SR04
float echoTime;            // Variable to store the time it takes for a ping 
                           // to bounce off an object.
float calculatedDistance;  // Variable to store the distance calculated from 
                           // the echo time.
//------------------ Global Variables -----------------------------
float Temperature = 0.00;       // Initialize variable to record temperature
float Photoresistor = 0.00;     // Initialize variable to record photoresistor values
float Ultrasonic = 0.00;        // Initialize variable to record ultrasonic values
// Initialize variables to compare with sensors threshold and make decisions
char statusTemperature = 'LOW';
char oldstatusTemperature = 'LOW';
char statusPhotoresistor = 'LOW';
char oldstatusPhotoresistor = 'LOW';
char statusUltrasonic = 'LOW';
char oldstatusUltrasonic = 'LOW';
//---------------------- Setup() ----------------------------------
void setup() {
//----------------- 2-way Communication ---------------------------
//  ***************************************************************
//  MAKE SURE YOU SUBSCRIBE TO YOUR PEERS PUBLICATIONS (Neal-Seth, Neal-Rahul, or Seth-Rahul)
//  ***************************************************************
//    Particle.subscribe("Message4Neal", NealHandler);
    Particle.subscribe("Message4Seth", SethHandler);
    Particle.subscribe("Message4Rahul", RahulHandler);
//  ***************************************************************
//--------------------- ThingSpeak --------------------------------
    ThingSpeak.begin(client);
//--------------------- LCD Screen --------------------------------    
    lcd.begin(16, 2);              // Set up the LCD's number of columns and rows:
    lcd.print("Temp. (Deg. F)");   // Print a message to the LCD.
//------------------- Serial Monitor ------------------------------  
	Serial.begin(9600);          // Initialize serial communication 
    delay(1000);                 // Allow time for the serial monitor to settle.
    Serial.println("Starting Refrigerator Monitoring System...");
//----------------- Temperature Sensor ----------------------------      
	dht.begin();
//----------------- Ultrasonic Sensor ----------------------------- 	
    pinMode(trigPin, OUTPUT);    // The trigger pin will output pulses of electricity
    pinMode(echoPin, INPUT);     // The echo pin will measure the duration of pulses 
                                 // coming back from the distance sensor.
}
//---------------------- loop() -----------------------------------
void loop() {
//----------------- Sensor Measurements ---------------------------
//	delay(2000);                  //Wait a few seconds between measurements.
//  Reading temperature or humidity takes about 250 milliseconds!
//  Sensor readings may also be up to 2 seconds 'old' (its a // very slow sensor)
  float h = dht.getHumidity();     // Read Humidity
  float t = dht.getTempCelcius();  // Read temperature (Celsius units)
  float readings_T[10];            // Create array to store temperature measurements
  float readings_P[10];            // Create array to store photoresistor measurements
  float readings_U[10];            // Create array to store ultrasonic measurements
  float temperature;               // Variable to sort the temperature measurements
  float photoresistor;             // Variable to sort the photoresistor rmeasurements
  float ultrasonic;                // Variable to sort the ultrasonic measurements
// Collect 10 temperature, 10 photoresistor, and 10 ultrasonic readings    
  for (int i=0;i<10;i++){
    temperature = dht.getTempFarenheit();  // Read temperature (Farenheit units)
    photoresistor = analogRead(PHOPIN);    // Read photoresistor value (unitless)
    //send out an ultrasonic pulse that's 10ms long
    digitalWrite(trigPin, LOW);    // Send low to get a clean pulse beforehand
    delayMicroseconds(10);         // Let it settle
    digitalWrite(trigPin, HIGH);   // Send high to trigger device
    delayMicroseconds(10);         // Let it settle
    digitalWrite(trigPin, LOW);    // Send low to get a clean pulse
    delayMicroseconds(10);         // Let it settle
    echoTime = pulseIn(echoPin, HIGH); // Measure pulse coming back in microseconds
    calculatedDistance = echoTime / 57.971;  // Calculate the distance (in cm) of the 
                                           // object that reflected the pules.
    // 1/(345*100*10^(-6)/2)=57.9710
    ultrasonic = calculatedDistance;    // Ultrasonic value (cm)
    // Assign a value of zero to nan measurements
    if (isnan(temperature)){
        temperature = 0.0;
    }
    if (isnan(photoresistor)){
       photoresistor = 0;
    }
    if (isnan(ultrasonic)){
       ultrasonic = 0.00;
    }  
    readings_T[i]=temperature;         // Store temperature values in an array
    readings_P[i]=photoresistor;       // Store photoresistor values in an array
    readings_U[i]=ultrasonic;          // Store ultrasonic values in an array
    delay(1000);                       // Collect data every second
  }
  // Order the 10 temperature, 10 photoresistor, and 10 ultrasonic readings in ascending order  
  for (int i=0;i<10;i++){                  // Loop for ascending order
    for (int j=0;j<10;j++){                // Loop for comparing other values
      if (readings_T[j]>readings_T[i]){    // Comparing other array elements
        float tmpT = readings_T[i];        // Using temp var for storing last value
        readings_T[i]=readings_T[j];       // Replacing value
        readings_T[j]=tmpT;                // Storing last value
      }
    }
  }
  for (int i=0;i<10;i++){                  // Loop for ascending order
    for (int j=0;j<10;j++){                // Loop for comparing other values
      if (readings_P[j]>readings_P[i]){    // Comparing other array elements
        float tmpP = readings_P[i];        // Using temp var for storing last value
        readings_P[i]=readings_P[j];       // Replacing value
        readings_P[j]=tmpP;                // Storing last value
      }
    }
  }
  for (int i=0;i<10;i++){                  // Loop for ascending order
    for (int j=0;j<10;j++){                // Loop for comparing other values
      if (readings_U[j]>readings_U[i]){    // Comparing other array elements
        float tmpU = readings_U[i];        // Using temp var for storing last value
        readings_U[i]=readings_U[j];       // Replacing value
        readings_U[j]=tmpU;                // Storing last value
      }
    }
  }
  // For debugging puposes
  /*  Serial.print("reading 1  "); Serial.println(readings_T[0]); Serial.println(readings_P[0]); Serial.println(readings_U[0]);
      Serial.print("reading 2  "); Serial.println(readings_T[1]); Serial.println(readings_P[1]); Serial.println(readings_U[1]);
      Serial.print("reading 3  "); Serial.println(readings_T[2]); Serial.println(readings_P[2]); Serial.println(readings_U[2]);
      Serial.print("reading 4  "); Serial.println(readings_T[3]); Serial.println(readings_P[3]); Serial.println(readings_U[3]);
      Serial.print("reading 5  "); Serial.println(readings_T[4]); Serial.println(readings_P[4]); Serial.println(readings_U[4]);
      Serial.print("reading 6  "); Serial.println(readings_T[5]); Serial.println(readings_P[5]); Serial.println(readings_U[5]);
      Serial.print("reading 7  "); Serial.println(readings_T[6]); Serial.println(readings_P[6]); Serial.println(readings_U[6]);
      Serial.print("reading 8  "); Serial.println(readings_T[7]); Serial.println(readings_P[7]); Serial.println(readings_U[7]);
      Serial.print("reading 9  "); Serial.println(readings_T[8]); Serial.println(readings_P[8]); Serial.println(readings_U[8]);
      Serial.print("reading 10 "); Serial.println(readings_T[9]); Serial.println(readings_P[9]); Serial.println(readings_U[9]); */
  // Select and print the median value of the arrays
  Temperature = readings_T[5];
  Photoresistor = readings_P[5];
  Ultrasonic = readings_U[5]; 
  Serial.print("Temperature    ");    Serial.print(Temperature,1);      Serial.println(" deg. F.");
  Serial.print("Photoresistor  ");    Serial.print(Photoresistor,0);    Serial.println(" (unitless)");
  Serial.print("Ultrasonic     ");    Serial.print(Ultrasonic,2);       Serial.println(" cm\n");
  // Program Logic for decision making
  // Temperature Decision Making
  if (Temperature>40.00) {
      statusTemperature = HIGH;
  }
  else {
      statusTemperature = LOW;
  }
  
  if (oldstatusTemperature == LOW && statusTemperature == HIGH) {
      Serial.println("Refrigerator temperature changed to unsafe\n\n");
  }
  else if (oldstatusTemperature == HIGH && statusTemperature == LOW) {
      Serial.println("Refrigerator temperature changed to safe\n\n");
  }
  else {
    // if the data is something else, don't do anything.
  }
  
 // Photoresistor Decision Making
  if (Photoresistor>3200.00) {
      statusPhotoresistor = LOW;
  }
  else {
      statusPhotoresistor = HIGH;
  }
  
  if (oldstatusPhotoresistor == LOW && statusPhotoresistor == HIGH) {
      Serial.println("Refrigerator Light was turned On\n\n");
  }
  else if (oldstatusPhotoresistor == HIGH && statusPhotoresistor == LOW) {
      Serial.println("Refrigerator Light was turned Off\n\n");
  }
  else {
    // if the data is something else, don't do anything.
  }

 // Ultrasonic Decision Making
  if (Ultrasonic<20.00) {
      statusUltrasonic = LOW;
  }
  else {
      statusUltrasonic = HIGH;
  }
  
  if (oldstatusUltrasonic == LOW && statusUltrasonic == HIGH) {
      Serial.println("Refrigerator Door changed to Open\n\n");
  }
  else if (oldstatusUltrasonic == HIGH && statusUltrasonic == LOW) {
      Serial.println("Refrigerator Door changed to Closed\n\n");
  }
  else {
    // if the data is something else, don't do anything.
  }

  // Decision making for the Temperature, the Photoresistor, and the Ultrasonic Sensor Readings Altogether
  if (statusTemperature == HIGH && statusPhotoresistor == HIGH && statusUltrasonic == HIGH) {
  // if (statusPhotoresistor == HIGH && statusUltrasonic == HIGH) { // for testing purposes
    Serial.println("Refrigerator door is open and needs to be closed\n\n");
    //  ***************************************************************
    //  MAKE SURE YOU COMMENT OUT THE TWO CHANNELS YOU ARE NOT USING (Neal-Seth, Neal-Rahul, or Seth-Rahul)
    //  ***************************************************************
    Particle.publish("Message4Neal","Refrigerator door needs to be closed");
    //  Particle.publish("Message4Seth","Refrigerator door needs to be closed");
    //  Particle.publish("Message4Rahul","Refrigerator door needs to be closed");
    //  ***************************************************************
  }
  else if (statusTemperature == LOW && statusPhotoresistor == LOW && statusUltrasonic == LOW) {
    Serial.println("Refrigerator door is currently closed\n\n");
  }
  else {
    // if the data is something else, don't do anything.
  }
  oldstatusTemperature = statusTemperature;
  oldstatusPhotoresistor = statusPhotoresistor;
  oldstatusUltrasonic = statusUltrasonic;
//--------------------- ThingSpeak --------------------------------
  ThingSpeak.setField(1,Temperature);
  ThingSpeak.setField(2,Photoresistor);
  ThingSpeak.setField(3,Ultrasonic);
//  ***************************************************************
//  MAKE SURE YOU COMMENT OUT THE TWO CHANNELS YOU ARE NOT USING (Neal-Seth, Neal-Rahul, or Seth-Rahul)
//  ***************************************************************
    ThingSpeak.writeFields(NealChannelNumber_T_P_U, NealWriteAPIKey_T_P_U);
//    ThingSpeak.writeFields(SethChannelNumber_T_P_U, SethWriteAPIKey_T_P_U);    
//    ThingSpeak.writeFields(RahulChannelNumber_T_P_U, RahulWriteAPIKey_T_P_U);
//  ***************************************************************
//  delay(20000); // ThingSpeak will only accept updates every 15 seconds.
//----------------- Sensor Measurements ---------------------------
//	Serial.println(Time.timeStr());       // if needed later
//	String timeStamp = Time.timeStr();    // if needed later
//  ***************************************************************
//  MAKE SURE YOU COMMENT OUT THE TWO CHANNELS YOU ARE NOT USING (Neal-Seth, Neal-Rahul, or Seth-Rahul)
//  ***************************************************************
	Particle.publish("NealRefrigeratorData", String::format("Temp(°F): %4.1f, Photo(Ohms): %4.0f, Ultras(cm): %4.2f", Temperature, Photoresistor, Ultrasonic));
//	Particle.publish("SethRefrigeratorData", String::format("Temp(°F): %4.1f, Photo(Ohms): %4.0f, Ultras(cm): %4.2f", Temperature, Photoresistor, Ultrasonic));
//	Particle.publish("RahulRefrigeratorData", String::format("Temp(°F): %4.1f, Photo(Ohms): %4.0f, Ultras(cm): %4.2f", Temperature, Photoresistor, Ultrasonic));
//  ***************************************************************
//--------------------- ThingSpeak --------------------------------
    delay(10000); // ThingSpeak will only accept updates every 15 seconds.
//    delay(10000); //   Collect data every 30 seconds (10s+10s+10s)
    delay(280000); //   Collect data every 5 minutes (280s+10s+10s)
//--------------------- LCD Screen --------------------------------
    lcd.setCursor(0, 1);  // set the cursor to column 0, line 1
//  (note: line 1 is the second row, since counting begins with 0):
    lcd.print(Temperature);      // print the temperature using the LCD Screen
} // Loop end bracket 
//----------------- 2-way Communication ---------------------------
// Now for the myHandler function, which is called when the cloud tells us that our buddy's event is published.
void NealHandler(const char *event, const char *data)
{
  if (strcmp(data,"Refrigerator door needs to be closed")==0) {
    Particle.publish("Message4Seth","Please remind Neal to close the refrigerator door");
    Particle.publish("Message4Rahul","Please remind Neal to close the refrigerator door");
  }
  else {
    // if the data is something else, don't do anything.
  }
}

void SethHandler(const char *event, const char *data)
{
  if (strcmp(data,"Refrigerator door needs to be closed")==0) {
    Particle.publish("Message4Neal","Please remind Seth to close the refrigerator door");
    Particle.publish("Message4Rahul","Please remind Seth to close the refrigerator door");
  }
  else {
    // if the data is something else, don't do anything.
  }
}

void RahulHandler(const char *event, const char *data)
{
  if (strcmp(data,"Refrigerator door needs to be closed")==0) {
    Particle.publish("Message4Neal","Please remind Rahul to close the refrigerator door");
    Particle.publish("Message4Seth","Please remind Rahul to close the refrigerator door");
  }
  else {
    // if the data is something else, don't do anything.
  }
}