#include <Time.h>
#include <TimeLib.h>

////////// Inputs //////////
int VoltPin = 15;
int AmpPin = 14;  
int ResetPin = 1;    //Digital
int Reset;


////////// Variables //////////
double Volts;
double Amps;
double Watts = 0;
double WattsAvg = 0;
double WattsSum = 0;
double WattHours = 0;
double TotalWattHours = 0;
double PrevWattHours = 0;
double TotalKiloWattHours = 0;

int Currentsecond;
int Currentminute;
int Currenthour;
int Currentday;
int Currentmonth;
int Currentyear;
int Previoussecond;
int Previousminute;
int Prevhour;
unsigned long CurrentTime;
unsigned long PrevTime;

//Library for the Display
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,20, 4); 

#include <SD.h>
const int chipSelect = BUILTIN_SDCARD;




void setup() {
  
  Serial.begin(115200);
  
  //Wire.begin();
  Wire.setSDA(18);
  Wire.setSCL(19);

  pinMode(1, INPUT_PULLUP);

   
////////// Initialize the lcd //////////
  lcd.init();                      
  lcd.backlight();

  lcd.setCursor(4,1);
  lcd.print("SOLAR LOGGER");

  delay(2000);
  lcd.clear();

////////// Time & Date Set //////////
  setTime(15, 00, 0, 26, 7, 2019); // Hour Minute Second Day Month Year


}




void loop() {
////////// Time & Date //////////
  Currentsecond = second();
  Currentminute = minute();
  Currenthour = hour();
  Currentday = day();
  Currentmonth = month();
  Currentyear = year();

  CurrentTime = millis();
  
////////// Measurements //////////
  Volts = (analogRead(VoltPin)-2)*0.0161;  // (Raw volt value - Offset)*multiplier
  //Volts = analogRead(A0);     // Read raw volt value
  Amps = (analogRead(A0)-761)*0.082;     // (Raw amp value - Offset)*multiplier
  //Amps = analogRead(A0);      // Read raw amp value

  Watts = Volts * Amps;
  
  if(Amps < 0){
    Watts = 0;
  }

  
  if((CurrentTime-PrevTime) < 0){
    Watts = 0;
  }

    WattHours = WattHours + Watts * ((CurrentTime - PrevTime) * 0.000000277);
    TotalWattHours = (TotalWattHours + Watts * ((CurrentTime - PrevTime) * 0.000000277));
    TotalKiloWattHours = TotalWattHours * 0.001;
     
    PrevTime = CurrentTime;
  
  if(millis() > 4294967000){
    PrevTime = 0;
  
 }
   Reset = digitalRead(1); 
  if(Reset == LOW){
    WattHours = 0;
  }

////////// LCD //////////
if(Currentsecond != Previoussecond){
// First line  
  lcd.setCursor(1, 0);  // (column, line)
  lcd.print(Volts, 2);
  lcd.setCursor(5, 0);
  lcd.print("V");
  lcd.setCursor(8, 0);
  lcd.print(Amps, 2);
  lcd.setCursor(12, 0);
  lcd.print("A ");

  if(Watts > 100){
    lcd.setCursor(15, 0);
    lcd.print(Watts, 0);
  }
  if(Watts > 10 && Watts < 100){
    lcd.setCursor(15, 0);
    lcd.print(" ");
    lcd.print(Watts, 0);
  }
  if(Watts < 10){
    lcd.setCursor(15, 0);
    lcd.print("  ");
    lcd.print(Watts, 0);
  }
        
    

  lcd.setCursor(18, 0);
  lcd.print("W ");    
  
// Second line
  lcd.setCursor(3, 1);
  lcd.print("Energy");
  lcd.setCursor(11, 1);
  lcd.print(WattHours);
  lcd.setCursor(14, 1);
  lcd.print("Wh");

  
// Third line
  lcd.setCursor(3, 2);
  lcd.print("Total");
  lcd.setCursor(10, 2);
  lcd.print(TotalKiloWattHours, 2);
  lcd.setCursor(13, 2);
  lcd.print("kWh");


// Fourth line
  if(Currenthour < 10){
  lcd.setCursor(1, 3);
  lcd.print("0");
  lcd.print(Currenthour);
  }
  else{
  lcd.setCursor(1, 3);
  lcd.print(Currenthour);    
  }
  lcd.setCursor(3, 3);
  lcd.print(":");
  if(Currentminute < 10){
    lcd.setCursor(4, 3);
    lcd.print("0");
    lcd.print(Currentminute);
  }
  else{
  lcd.setCursor(4, 3);
  lcd.print(Currentminute);
  }
  if(Currentday < 10){
  lcd.setCursor(9, 3);
  lcd.print("0");
  lcd.print(Currentday); 
  }
  else{
  lcd.setCursor(9, 3);
  lcd.print(Currentday);     
  }
  lcd.setCursor(11, 3);
  lcd.print("/");
  if(Currentmonth < 10){
  lcd.setCursor(12, 3);
  lcd.print("0"); 
  lcd.print(Currentmonth);
  }
  else{
  lcd.setCursor(12, 3); 
  lcd.print(Currentmonth);
  }
  lcd.setCursor(14, 3);
  lcd.print("/");
  lcd.setCursor(15, 3);
  lcd.print(Currentyear);
  
  Previoussecond = Currentsecond;
}
////////// SD Card //////////
  if(Currenthour != Prevhour){
    
    WattsAvg = TotalWattHours - PrevWattHours;
    PrevWattHours = TotalWattHours;

    SD.begin(chipSelect);
    
    String dataString = "";
    dataString += String(Currenthour);
    dataString += ":";
    dataString += String(Currentminute);
    dataString += ",";
    dataString += String(Currentday);
    dataString += "/";
    dataString += String(Currentmonth);
    dataString += ",";
    dataString += String(Volts);
    dataString += ",";    
    dataString += String(WattsAvg);
    dataString += ",";
    dataString += String(TotalWattHours);
    dataString += ",";

    File dataFile = SD.open("SOLARLOG.txt", FILE_WRITE);

    if (dataFile) {
      dataFile.println(dataString);
      dataFile.close();
      Serial.println(dataString);
    }
    else {
      Serial.println("error opening datalog.txt");
    }

    Previousminute = Currentminute;
    Prevhour = Currenthour;
  }

////////// Serial ////////// 
/*
Serial.print("Time: ");
Serial.print(CurrentHour);
Serial.print(":");
Serial.print(Currentminute);
Serial.print("  Date: ");
Serial.print(Currentday); 
Serial.print("/");
Serial.print(Currentmonth); 
Serial.print("/");
Serial.print(Currentyear); 
Serial.print("  Volts: ");
Serial.print(Volts); 
Serial.print("  Amps: ");
Serial.print(Amps); 
Serial.print("  Watts: ");
Serial.print(Watts); 
Serial.println();
*/

delay(20);
}