Use an Arduino to Measure Voltage, Current & Resistance

AC voltage

To measure AV voltage you will need to have a zmpt101b module. All you have to do is connect vcc of the module to 5v of the Arduino GND to ground of the Arduino and vout to analogue pin 0 of the Arduino. Once all the connections are made you just need to upload the code to the Arduino and open the serial monitor and the voltage will be displayed. You can measure up to 300v with this module.

DC Voltage

To measure DC voltage you will need to have a 100k resistor and connect it between ground and analogue pin 0 and then you will want to connect the 1m resistor to analogue pin 0 and then connect the other side of this resistor the voltage you would like to test. Once all the connections are made you just need to upload the code to the Arduino and open the serial monitor and the voltage will be displayed. With these resistor values you can measure up to 50v.

void setup() 
{ 
 Serial.begin(9600); 
}
void loop() {
int Input  = analogRead(A0); // Read the analog  value 
double voltage = Input * (5.0 / 1024.0) * 10; //convert the value to volts
Serial.print("Voltage: ");
Serial.print(voltage);
Serial.println(" V");
delay(2500);
}

Current

To measure current you will need to have a ACS712 hall effect current sensor module. All you have to do is connect vcc of the module to 5v of the Arduino GND to ground of the Arduino and vout to analogue pin 0 of the Arduino. Once all the connections are made you just need to upload the code to the Arduino and open the serial monitor and the current will be displayed. I used the 20amp version so the mv/amp value is 100 but if you have a different version you will need to change this.

const int analogIn = A0; //the pin the sensor is connected to
double Value= 0; 
double ACSoffset = 2500; // ofset for the ACS712
double mVAmp = 100;// mv per amp for your sensor you can find this on its data sheet
double Amps = 0;
double Voltage = 0;
void setup(){ 
Serial.begin(9600);
}
void loop(){
Value = analogRead(analogIn);
Voltage = (Value / 1024) * 5000; // converts the signal in to mA
Amps = ((Voltage - ACSoffset) / mVAmp);
Serial.print("\t Amps = "); // displays the current measured
Serial.println(Amps,3); // sets the number of digits displayed after the decimal point 
delay(2500); // waits 2.5 seconds then repeats the process 

Resistance

To measure resistance you will need to have a 1k resistor and connect it between ground and analogue pin 0 and then you will want to connect the resistor you would like to test to analogue pin 0 and 5v. Once all the connections are made you just need to upload the code to the Arduino and open the serial monitor and the resistance will be displayed.

const int analogIn= 0; // //the pin the center of the voltage devider is connected to
int Value= 0; 
int Vin= 5;
double buffer= 0;
double Vout= 0; 
double Rtest= 0;
double R1= 1000;
void setup()
{
Serial.begin(9600);
}
void loop()
{
Value= analogRead(analogIn);
if(Value) 
buffer= Value * Vin;
Vout= (buffer)/1024.0;
buffer= (Vin/Vout) -1;
Rtest= R1 * buffer;
Serial.print("Resisor value: ");//displays the resistance
Serial.println(Rtest);//displays the value of the resistor
delay(2500);

Acknowledgement

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