/*
  DC wattmeter by GCSCREATIONS
*/
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
// Set the LCD address to 0x3F for a 16 chars and 2 line display,Address may vary,find out your address.
LiquidCrystal_I2C lcd(0x3F, 16, 2);
// end of settings for LCD1602 with I2C
/*
#include <LiquidCrystal.h>
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);*///if you are using without I2C module


int analogInput1 = 1;//For measuring voltage
int analogInput2=2;//For measuring current

float vout = 0.0;//output from voltage divider circuit.
float vin = 0.0;//Actual value of voltage
float R1 = 220000.0; // resistance of R1 (220K)
float R2 = 100000.0; // resistance of R2 (100K)



double current=0;//Actual value of current
double rawvoltage=0;//output from current sensor
float power=0;//For calculating power

void setup() {
  Serial.begin(9600);
  pinMode(analogInput1, INPUT);
  pinMode(analogInput2,INPUT);
  lcd.begin();
  lcd.setCursor(2, 0);
  lcd.print("DC WATTMETER");
  lcd.setCursor(2, 1);
  lcd.print("0-16V/0-20A");
  delay(2000);
  lcd.clear();

}
void loop() 
//--------------------------------------------------------------------------------Voltage measurement
{
  for(int j=0;j<1000;j++)
  {
     vout = (vout +(analogRead(analogInput1)*5.0)/1024);
     delay(0.2);
  }
  vout=vout/1000;
  vin = vout / (R2 / (R1 + R2));
  vin=vin+0.2;// For calibration,you can change this value according to your voltage deviation.
  Serial.println(vin);
  if (vin <= 0.4)
  {
    vin = 0.0;
  }
//------------------------------------------------------------------------------------Current measurement
  for(int i = 0; i < 1000; i++) 
  {  
  rawvoltage = (rawvoltage + (analogRead(analogInput2)*5.0)/1024); // (5 V / 1024 (Analog) = 0.0049) which converter Measured analog input voltage to 5 V Range
  delay(0.8);
  }
  rawvoltage = rawvoltage /1000;

  current = (rawvoltage - 2.49)/ 0.100; // Sensed voltage is converted to current
  current=current-0.025;//For calibration,you can change this value according to your current deviation.
  if(current<0.00)
  {
    current=0;
  }
  else
  {
    
  current=current+0.00;//For calibration,you can change this value according to your current deviation.
    
  }
//-------------------------------------------------------------------------------------Calculating power
  power=vin*current;//For calculating power.

//-------------------------------------------------------------------------------------Displaying parameters 
  
  
  lcd.setCursor(0,0);
  lcd.print("V:");
  lcd.print(vin,2);//Displaying Voltage.
  lcd.setCursor(7,0);
  lcd.print("V");
  /*lcd.setCursor(9,0);
  lcd.print("v:");
  lcd.print(vout,2);*///For troubleshooting the output from the voltage divider circuit.
  

  
  lcd.setCursor(0,1);
  lcd.print("I:");
  lcd.print(abs(current),3);//Displaying Current.
  lcd.print("A");
  /*lcd.setCursor(9,0);
  lcd.print("i:");
  lcd.print(rawvoltage,2);*///For troubleshooting the output from the current sensor.

  lcd.setCursor(9,1);
  lcd.print("P:");
  lcd.print(power);//Displaying Power
  lcd.print("W");
  delay(1000);
  
}