Displaying error values if no input from Analog ports at MEGA2560

Hi,
I am new to Arduino, my arduino codes and simulation is run without error but the problem is
Here
1.I have used 7 analog inputs (A0 to A6) and for A3 no issue,(A0 to A2 = L1,L2,L3 Voltage measurement and A4 to A6 = L1,L2,L3 current measurement method of analog input is 0 to 5V)
2.If A0 to A2 no input and from A4 to A6 analog reading value shows/LCD display(16x2) correctly according to the formula used.
3.when A0 to A2 get input and the corresponding A4 to A6 output value shows in LCD display with multiplication from A0 to A3 values even A4 to A6 No input given.
how to resolve this
Advance Thanks for your replay

When you say "no input" do you mean the pin is tied to ground, or do you simply mean random antenna mode?

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my analog input is 0 to 5V (step dwon voltages for line of L1,L2 &L3 voltage and current measuring)

What does this mean, please?

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means A0 =0V, A1=0V, A2=0V that is analog input is 0V

Hi, @K.K
Welcome to the forum.

Please read the post at the start of any forum , entitled "How to use this Forum".

This will help with advice on how to present your code and problems.

Can you please post your code and a circuit diagram?
What are you using to get the 3 phase voltages and current?

Thanks.. Tom... :smiley: :+1: :coffee: :australia:

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I think it's time for code, schematic and a description of what you're seeing, and how that differs from what you expect to see

Hi,
You need to read the link on post#6, it will show you how to post your code in a scrolling window.
Or read this link.
To add code please click this link;

Thanks.. Tom... :smiley: :+1: :coffee: :australia:

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#include <LiquidCrystal.h>
#define rs 27
#define en 26
#define d4 25
#define d5 24
#define d6 23
#define d7 22
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
int delaytime = 2;
int TimeloopR1 = 0;
int TimeloopY1 = 0;
int TimeloopB1 = 0;
unsigned long vrcurrenttime = 0;
unsigned long vycurrenttime = 0;
unsigned long vbcurrenttime = 0;

unsigned long vrprevioustime = 0;
unsigned long vyprevioustime = 0;
unsigned long vbprevioustime = 0;

int sec = 0;
int sec1 = 0;
int sec2 = 0;
const int RPhase = A0; //R Phase analog input from R phase stepdown voltage
const int YPhase = A1; //Y Phase analog input from R phase stepdown voltage
const int BPhase = A2; //B Phase analog input from R phase stepdown voltage

const int RPhaseIR = A4; //R Phase analog input from R phase stepdown current measurment to voltage
const int YPhaseIY = A5; //Y Phase analog input from R phase stepdown current measurment to voltage
const int BPhaseIB = A6; //B Phase analog input from R phase stepdown current measurment to voltage

const int Tempsensor = A3; //Tempsensor TMP35/36/37 Temprature sensor analog input
int thresholdValue = 0;
int celsius = 0;

void setup()
{
  Serial.begin(9600);
  lcd.begin(16, 2);
  pinMode(A0, INPUT); //R Phase analog input from R phase stepdown voltage
  pinMode(A1, INPUT); //Y Phase analog input from R phase stepdown voltage
  pinMode(A2, INPUT); //B Phase analog input from R phase stepdown voltage
  pinMode(A3, INPUT); //Temprature sensor analog input
  pinMode(A4, INPUT); //R Phase analog input from R phase stepdown current measurment to voltage
  pinMode(A5, INPUT); //Y Phase analog input from R phase stepdown current measurment to voltage
  pinMode(A6, INPUT); //B Phase analog input from R phase stepdown current measurment to voltage
  pinMode(3, INPUT); //TimeloopR1 from pin2
  pinMode(5, INPUT); //TimeloopY1 from pin4
  pinMode(7, INPUT); //TimeloopB1 from pin6
  pinMode(2, OUTPUT); //TimeloopR1 to pin3
  pinMode(4, OUTPUT); //TimeloopR1 to pin5
  pinMode(6, OUTPUT); //TimeloopR1 to pin7
  pinMode(8, OUTPUT); //Trip to R Phase fail VK1
  pinMode(9, OUTPUT); //Trip to R Phase fail VK2
  pinMode(10, OUTPUT); //Trip to R Phase fail VK3
  pinMode(11, OUTPUT); //Phase fail Indication LED1 or Buzzer
  pinMode(12, OUTPUT); //All phases are healthy LED2
  pinMode(13, OUTPUT); //Panel Cooling Fan K7
  pinMode(28, OUTPUT); //OverCurrent Trip IK4
  delay(1000);
}
void loop()
{
  delay(500);
  lcd.clear();
  int vrout = analogRead(RPhase);
  int vyout = analogRead(YPhase);
  int vbout = analogRead(BPhase);
  int RVolt = (vrout * ( 5.0 / 1023)) * 50.55;
  int YVolt = (vyout * ( 5.0 / 1023)) * 50.55;
  int BVolt = (vbout * ( 5.0 / 1023)) * 50.55;
  int IRin = analogRead(RPhaseIR);
  int IYin = analogRead(YPhaseIY);
  int IBin = analogRead(BPhaseIB);
  int RCurrent = (IRin * ( 5.0 / 1023)) * 08.00;
  int YCurrent = (IYin * ( 5.0 / 1023)) * 08.00;
  int BCurrent = (IBin * ( 5.0 / 1023)) * 08.00;

  //R Phase Voltage Condition Checks
  if ( RVolt < 180)
  {
    digitalWrite(2, HIGH);
  }
  else if ( (RVolt >= 180)  &&  (RVolt <= 240) )
  {
    digitalWrite(2, LOW);
  }
  if ( RVolt > 240)
  {
    digitalWrite(2, HIGH);
  }
  else if ( (RVolt >= 180)  &&  (RVolt <= 240) )
  {
    delay(0);
    digitalWrite(2, LOW);
  }
  vrcurrenttime = millis();
  if (digitalRead(3) == HIGH && TimeloopR1 == 0 && digitalRead(8) == LOW)
  {
    TimeloopR1 = 1;
    sec = delaytime;
  }
  if (TimeloopR1 == 1)
  {
    if ((vrcurrenttime - vrprevioustime) > 1000)
    {
      sec--;
      vrprevioustime = vrcurrenttime;
      if (sec <= 0)
      {
        TimeloopR1 = 0;
        digitalWrite(8, HIGH);
        sec = 0;
      }
    }
  }
  if (digitalRead(3) == LOW && TimeloopR1 == 0)
  {
    TimeloopR1 = 0;
    sec = 0;
    digitalWrite(8, LOW);
  }
  //Y Phase Voltage Condition Checks
  if ( YVolt < 180)
  {
    digitalWrite(4, HIGH);
  }
  else if ( (YVolt >= 180)  &&  (YVolt <= 240) )
  {
    digitalWrite(4, LOW);
  }
  if ( YVolt > 240)
  {
    digitalWrite(4, HIGH);
  }
  else if ( (YVolt >= 180)  &&  (YVolt <= 240) )
  {
    digitalWrite(4, LOW);
  }
  vycurrenttime = millis();
  if (digitalRead(5) == HIGH && TimeloopY1 == 0 && digitalRead(9) == LOW)
  {
    TimeloopY1 = 1;
    sec1 = delaytime;
  }
  if (TimeloopY1 == 1)
  {
    if ((vycurrenttime - vyprevioustime) > 1000)
    {
      sec1--;
      vyprevioustime = vycurrenttime;
      if (sec1 <= 0)
      {
        TimeloopY1 = 0;
        digitalWrite(9, HIGH);
        sec1 = 0;
      }
    }
  }
  if (digitalRead(5) == LOW && TimeloopY1 == 0)
  {
    TimeloopY1 = 0;
    sec1 = 0;
    digitalWrite(9, LOW);
  }
  //B Phase Voltage Condition Checks
  if ( BVolt < 180)
  {
    digitalWrite(6, HIGH);
  }
  else if ( (BVolt >= 180)  &&  (BVolt <= 240) )
  {
    digitalWrite(6, LOW);
  }
  if ( BVolt > 240)
  {
    digitalWrite(6, HIGH);
  }
  else if ( (BVolt >= 180)  &&  (BVolt <= 240) )
  {
    digitalWrite(6, LOW);
  }
  vbcurrenttime = millis();
  if (digitalRead(7) == HIGH && TimeloopB1 == 0 && digitalRead(10) == LOW)
  {
    TimeloopB1 = 1;
    sec2 = delaytime;
  }
  if (TimeloopB1 == 1)
  {
    if ((vbcurrenttime - vbprevioustime) > 1000)
    {
      sec2--;
      vbprevioustime = vbcurrenttime;
      if (sec2 <= 0)
      {
        TimeloopB1 = 0;
        digitalWrite(10, HIGH);
        sec2 = 0;
      }
    }
  }
  if (digitalRead(7) == LOW && TimeloopB1 == 0)
  {
    TimeloopB1 = 0;
    sec2 = 0;
    digitalWrite(10, LOW);
  }

  //Overcurrent Trip for IK4
  if (RCurrent > 25 || YCurrent > 25 || BCurrent > 25)
  {
    digitalWrite(28, HIGH); // Overcurrent trip relay IK4
  }

  //Any Phase Fail Blink LED1 or Buzzer
  if (digitalRead(7) == HIGH || digitalRead(5) == HIGH || digitalRead(3) == HIGH)
  {
    digitalWrite(11, HIGH);
    delay(100);
    digitalWrite(11, LOW);
  }
  //All Phases are OK LED2
  if (digitalRead(7) == LOW && digitalRead(5) == LOW && digitalRead(3) == LOW)
  {
    digitalWrite(12, HIGH);
  }
  //LCD Display Details
  Serial.println(RVolt);
  Serial.println(YVolt);
  Serial.println(BVolt);
  lcd.setCursor(0, 0);
  lcd.print(" R    Y    B   V");
  lcd.setCursor(0, 1);
  lcd.print(RVolt);
  lcd.setCursor(5, 1);
  lcd.print(YVolt);
  lcd.setCursor(10, 1);
  lcd.print(BVolt);
  delay(200);
  Serial.println(RCurrent);
  Serial.println(YCurrent);
  Serial.println(BCurrent);
  lcd.setCursor(0, 0);
  lcd.print(" R    Y    B   I");
  lcd.setCursor(0, 1);
  lcd.print(RCurrent);
  lcd.setCursor(5, 1);
  lcd.print(YCurrent);
  lcd.setCursor(10, 1);
  lcd.print(BCurrent);
  delay(100);
  if (digitalRead(8) == HIGH)
  {
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("*R Under Voltage");
    delay(100);
  }

  // Temperature calculation and Panel Cooling Fan
  celsius = map(((analogRead(A3) - 20) * 3.04), 0, 1023, -40, 125);
  Serial.print(celsius);
  Serial.print(" C : ");
  if (celsius >= 38)
  {
    digitalWrite(13, HIGH);
  }
  else if (celsius < 38)
  {
    digitalWrite(13, LOW);
  }
}