Arduino Multimeter! (2)

Resistance Measurement

An object's resistance is mostly determined by the material it is made of. Electrical insulators, such as rubber, have a very high resistance and low conductivity, whereas electrical conductors, such as metals, have a very low resistance and great conductivity. Resistivity or conductivity are used to measure this relationship. Resistance and conductance are not just determined by the nature of a material; they also depend on the size of an object because these qualities are extensive rather than intensive. The resistance of a wire, for example, is higher when it is long and thin, and lower when it is short and thick. Except for superconductors, which have no resistance, all objects resist electrical current.

Materials for Resistance Measurement

1. • Arduino Uno
2. • Cables and Breadboard
3. • R1-1KΩ
4. • R2-Any Resistor from 50 to 500K

Schematic for Resistance Measurement

To test this circuit we just need to use any resistor from 50 to 500K.

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Code for Resistance Measurement

void setup () {
    Serial.begin (9600);
}

void loop () {
    int Value = analogRead (A0);
    float voltage = Value*(5.0/1024.0);
    float current = voltage / 1000;
    float VRx = 5 - voltage ;
    float Rx = VRx / current ;
    Rx = (5 - voltage) / current ;
    Serial.print ("Resistance:");
    Serial.print (Rx);
    Serial.println ("Ohms");
    delay (1000);
}
                        

To see the results you need to check the serial monitor!