Project 7 How to make a ammeter using Arduino UNO and ACS712 current sensor .
                                                               For 3-Phase Line

                                 The code for making this project is given below,,,

const int sensorIn1 = A0;                       /*FOR Current measurement Sensor 1*/

const int sensorIn2 = A1;                       /*FOR Current measurement Sensor 2*/

const int sensorIn3 = A2;                      /*FOR Current measurement Sensor 3*/

int mVperAmp = 66;                          // use 100 for 20A Module and 66 for 30A Module & 185 for 10A module

 

double Voltage1 = 0;

double VRMS1 = 0;

double AmpsRMS1 = 0;

double Voltage2 = 0;

double VRMS2 = 0;

double AmpsRMS2 = 0;

double Voltage3 = 0;

double VRMS3 = 0;

double AmpsRMS3 = 0;

void setup(){

  Serial.begin(9600);                   // Setting the baud rate of Serial Monitor (Arduino)

  delay(100);

}

void loop(){

 Voltage1 = getVPP1();

 VRMS1 = (Voltage1/2.0) *0.707;

 AmpsRMS1 = (VRMS1 * 1000)/mVperAmp;

 Serial.print(AmpsRMS1);

 Serial.println(" Amps RMS1");

  Voltage2 = getVPP2();

 VRMS2 = (Voltage2/2.0) *0.707;

 AmpsRMS2 = (VRMS2 * 1000)/mVperAmp;

 Serial.print(AmpsRMS2);

 Serial.println(" Amps RMS2");

  Voltage3 = getVPP3();

 VRMS3 = (Voltage3/2.0) *0.707;

 AmpsRMS3 = (VRMS3 * 1000)/mVperAmp;

 Serial.print(AmpsRMS3);

 Serial.println(" Amps RMS3");

}

float getVPP1()

{

  float result1;

  int readValue1;                         //value read from the sensor

  int maxValue1 = 0;                 // store max value here

  int minValue1 = 1024;           // store min value here

 

   uint32_t start_time = millis();

   while((millis()-start_time) < 1000)            //sample for 1 Sec

   {

       readValue1 = analogRead(sensorIn1);

       // see if you have a new maxValue

       if (readValue1 > maxValue1)

       {

           /*record the maximum sensor value*/

           maxValue1 = readValue1;

       }

       if (readValue1 < minValue1)

       {

           /*record the maximum sensor value*/

           minValue1 = readValue1;

       }

   }

  

   result1 = ((maxValue1 - minValue1) * 5.0)/1024.0;      // Subtract min from max

   return result1;

 }

 float getVPP2()

{

  float result2;

  int readValue2;                         //value read from the sensor

  int maxValue2 = 0;                 // store max value here

  int minValue2 = 1024;           // store min value here

 

   uint32_t start_time = millis();

   while((millis()-start_time) < 1000)              //sample for 1 Sec

   {

       readValue2 = analogRead(sensorIn2);

       // see if you have a new maxValue

       if (readValue2 > maxValue2)

       {

           /*record the maximum sensor value*/

           maxValue2 = readValue2;

       }

       if (readValue2 < minValue2)

       {

           /*record the maximum sensor value*/

           minValue2 = readValue2;

       }

   }

   result2 = ((maxValue2 - minValue2) * 5.0)/1024.0;   // Subtract min from max

   return result2;

 }

 float getVPP3()

{

  float result3;

  int readValue3;                           //value read from the sensor

  int maxValue3 = 0;                   // store max value here

  int minValue3 = 1024;              // store min value here

 

   uint32_t start_time = millis();

   while((millis()-start_time) < 1000)              //sample for 1 Sec

   {

       readValue3 = analogRead(sensorIn3);

       // see if you have a new maxValue

       if (readValue3 > maxValue3)

       {

           /*record the maximum sensor value*/

           maxValue3 = readValue3;

       }

       if (readValue3 < minValue3)

       {

           /*record the maximum sensor value*/

           minValue3 = readValue3;

       }

   }

   result3 = ((maxValue3 - minValue3) * 5.0)/1024.0;         // Subtract min from max

   return result3;

 }

If you have any query please comment below & keep watching.