const int adc1=34;

const int adc2=35;

const int adc3=32;

int value1=0, value2=0, value3=0;

float res1=0, res2=0, res3=0;

void setup() {

  Serial.begin(115200);

  pinMode(adc1, INPUT);    // Pins Port1 Connected to ADC Knobs

  pinMode(adc2, INPUT);

  pinMode(adc3, INPUT);

  delay(500);

}

void loop() {

  delay(1000);

  value1=analogRead(adc1);

  value2=analogRead(adc2);

  value3=analogRead(adc3);

  res1=float((value1*3.3)/4095);   //3.3v is maximum voltage applied as a input

  res2=float((value2*3.3)/4095);   //it is 12bit ADC hence dividing by 4095 gives actual voltage

  res3=float((value3*3.3)/4095);

 Serial.print("The output of ADC1= ");

 Serial.print(res1);

 delay(500);

 Serial.print("\t The output of ADC2= ");

 Serial.print(res2);

 delay(500);

 Serial.print("\t The output of ADC3= ");

 Serial.println(res3);

 delay(500);

}