Arduino Ohm Meter

//************************************************
//*                learnelectronics              *
//*                Arduino Ohm Meter             *
//*     original code by Iasonas Christoulakis   *
//*                                              *
//*      Modified by learnelectronics 9/28/21    *
//*        www.youtube.com/learnelectronics      *
//*                                              *
//*           email: arduino0169@gmail.com       *
//************************************************



#include <Wire.h>                                         //library for I2C
#include <Adafruit_SSD1306.h>                             //OLED driver
#define OLED_RESET 4                                      //required by the OLED driver
Adafruit_SSD1306 display(OLED_RESET);                     //initiate library

int analogPin= 0;                                         //pin to read voltage divider
int raw= 0;                                               //reading from pin
int Vin= 5;                                               //voltage out from arduino
float Vout= 0;                                            //initial value
float R1= 974;                                            //actual reading of known resistor
float R2= 0;                                              //initial value for UNKNOWN resistor
float buffer= 0;                                          //initail buffer value

void setup()   {

  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);              //startup the display
  display.display();                                      //show display buffer
  delay(2);                                               //wait very briefly
  display.clearDisplay();                                 //clear the display


}


void loop() {

raw= analogRead(analogPin);                                //read voltage at analog pin 0
if(raw)                                                    //if there is a reading, then
{
buffer= raw * Vin;                                         //multiply the reading by the value of vin
Vout= (buffer)/1024.0;                                     //set value of Vout to the whats in the buffer divided by 1024, the max value of the ADC
buffer= (Vin/Vout) -1;                                     //now make the buffer voltage in divided by voltage out -1
R2= R1 * buffer;                                           //and the value of the unknown is the known divided by the buffer

}
  display.clearDisplay();                                 //show the answer
  display.setCursor(0,0);
  display.setTextSize(1);
  display.setTextColor(WHITE);

display.print("Vout: ");
display.println(Vout);
display.print("R2: ");
display.println(R2);
display.display();

delay(1000);












}