Arduino power meter code - MAX471

/*********************************************************************
Power meter example. Author: ELECTRONOOBS. 08/05/2018
Tutorial video: https://www.youtube.com/watch?v=_PKQdEUam6Y
Tutorial link: http://www.electronoobs.com/eng_arduino_tut28.php
*********************************************************************/


//Inport the libraries
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

#define NUMFLAKES 10
#define XPOS 0
#define YPOS 1
#define DELTAY 2


#if (SSD1306_LCDHEIGHT != 32)
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif


//variables
float voltage = 0;
float current_voltage = 0;          //this maps the measured voltage in volts from 0 t 3.7V
float current =  0; 
float power=0;
float voltage_compenstion = 0;
float energy = 0;
int RawValue= 0;

unsigned long previousMillis = 0;
unsigned long loop_delay = 100;
unsigned long Time = 0;

void setup()   {                
  //Begin the display i2c omunication
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);  // initialize with the I2C addr 0x3C (for the 128x32)  
}


//THIS FUNCTION WILL MAP THE float VALUES IN THE GIVEN RANGE
float fmap(float x, float in_min, float in_max, float out_min, float out_max) {
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}

//This functions will calculate the curret, voltage, power and energy values
void get_values()
{
  voltage = (fmap(analogRead(A1),0.0,1023.0,0.0,3.7)) / 0.218;
  //The module gives one volt per Amp.
  RawValue = analogRead(A0); 
  current = (RawValue * 5.0 )/ 1024.0; // scale the ADC, we get current value in Amps
  
  power = voltage*current;              //Calculate power and energy
  energy = energy + (power/3600)/1000;
}



void loop() {
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= loop_delay)
  {
    previousMillis = currentMillis;
    get_values();
    Time = currentMillis / 1000;        //Get the elapsed time in seconds

    //Print all the values on the display
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(0,0);
    display.print(voltage);
    display.print("V");

    display.setCursor(60,0);
    display.print(current);
    display.print("A");

    display.setCursor(0,11);
    display.print(power);
    display.print("W");

    display.setCursor(60,11);
    display.print(energy);
    display.print("mWh");

    display.setCursor(100,22);
    display.print(Time);
    display.print("s");
        
    display.display();    //This functions will display the data
  }
}