DIY Ohmmeter using Arduino

1int analogPin= 0; //Analog Pin A0
2int raw= 0;
3int Vin= 5; //input
4  voltage 5 volts
5float Vout= 0;
6float R1= 1000; //mention R1(Known Resistance,in
7  my case 1000 Ohm)
8float R2= 0;
9float buffer= 0;
10
11void setup()
12{
13
14  Serial.begin(9600);
15}
16
17void loop()
18{
19  raw= analogRead(analogPin);
20
21  if(raw) 
22  { 
23    buffer= raw * Vin;
24    Vout= (buffer)/1024.0;
25    buffer=
26  (Vin/Vout) -1;
27    R2= R1 * buffer;
28    Serial.print("Output voltage: ");
29
30    Serial.print(Vout);
31    Serial.println(" Volts");
32    Serial.print("Resistor
33  value: ");
34    Serial.print(R2);
35    Serial.println(" Ohm");
36    delay(1000);
37
38  }
39}
40