#include<LiquidCrystal.h>


LiquidCrystal lcd(2,3,4,5,6,7);   //rs,e,d4,d5,d6,d7
// SELECTOR 
int select =A0;
int selvalue;
int selvout;
float selvin;

// DC VOLTMETER
int dc =A1;
int dcvalue;
int dcvout;
float dcvin;

// CAPACITOR METER
int cap=A4;
unsigned long time0,time1,time2; 
float c,null0;
byte kn,mk,i;

// RESISTOR 

float R1 =100000; // value of 1k resistor
float R2 = 0;


// DOIDE AND LED
 int DL =A3;
int DLvalue;
int DLvout;
float DLvin; 

// CONTIUINTY TESTER
int raw = 0;
int Vin = 5;
float Vout = 0;
float R11 = 1000;
float R22 = 0;
float buffer = 0;

int mode=1;



void setup() 
{
lcd.begin(16,2);
pinMode(select, INPUT);
 pinMode(dc, INPUT); 
 pinMode(DL, INPUT);
  pinMode(cap,INPUT);
 lcd.print("AKINFOYEKU SAM"); 
 lcd.setCursor(0, 1);
 lcd.print("MULTIMETER ----");
  delay(5000); 
 lcd.clear();
}

void loop() {
   selvalue = analogRead(select);
   selvout = selvalue * (5.0*11 / 1023);
   selvin=selvout*0.09;
    
    if (selvin >4.6)
{
mode=1; // 100V DC VOLTMETER

}

else if (selvin >4.3)
{

mode=2; // 600V DC VOLTMETER

}

else if (selvin >3.4)
{

mode=3; // AC VOLTMETER

}

else if (selvin >3.1)
{
mode=4;//  OHM METER

}

else if (selvin >2.8)
{

mode =5; // INDUCTOR METER

}
else if (selvin >2.4)
{

mode=6; // CONUITY TESTER

}

else if (selvin >2.0)
{

mode=7; // DOIDE AND LED TESTER

}
else if (selvin >1.6)
{

mode=8; // FREQUCY METER

}
 
  else if (selvin >1.2)
{

mode=9; // HFE METER

}


else 
{

mode=10; // CAPACITOR TESTER

}

 //////////////////////////////// 100V DC VOLTMETER MODE 1//////////////////////////////////  
  if( mode == 1 )
   
{
 lcd.setCursor(0, 0);
 lcd.print("DC Voltmeter100V"); 
 dcvalue = analogRead(dc);
 dcvout =  dcvalue * (5.0*22 / 1023);
 dcvin=dcvout*0.9;
 lcd.setCursor(0, 1);
 lcd.print("DC volt="); 
 lcd.print(dcvin,1); 
 lcd.print("V   "); 
}

 //////////////////////////////// 1000V DC VOLTMETER MODE 2//////////////////////////////////  
  if( mode == 2 )
   
{
 lcd.setCursor(0, 0);
 lcd.print("DC Voltmete1000V"); 
    
 dcvalue = analogRead(dc);
 dcvout =  dcvalue * (5.0*221 / 1023);
 dcvin=dcvout*0.9;
 lcd.setCursor(0, 1);
 lcd.print("DC volt="); 
 lcd.print(dcvin,1); 
 lcd.print("V   ");   
    
    
}


 //////////////////////////////// AC VOLTMETER MODE 3//////////////////////////////////  
  if( mode == 3 )
   
{
 lcd.setCursor(0, 0);
    
    
 lcd.print("AC Voltmete 600V"); 
}

 ////////////////////////////////  OHM METER MODE 4//////////////////////////////////  
  if( mode == 4 )
   
{
 lcd.setCursor(0, 0);
 lcd.print("  OHM METER      "); 
    
    raw = analogRead(DL);
    buffer  = raw * Vin;
    Vout = (buffer)/1023.0;
    buffer = (Vin/Vout) - 1;
    R2 = R1 * buffer;
     if (R2>1000000)
     {
       
  lcd.setCursor(0, 1);
 lcd.print("RES="); 
  lcd.print(R2/1000000,1);
  lcd.print("M");
       
     }
    
        else if (R2>1000)
     {
       
  lcd.setCursor(0, 1);
 lcd.print("RES="); 
  lcd.print(R2/1000,1);
  lcd.print(" K");
       
     }
     
    else
    {
      
      lcd.setCursor(0, 1);
 lcd.print("RES="); 
  lcd.print(R2,1);
  lcd.print("   "); 
      
      
    }
    
}



 //////////////////////////////// INDUCTOR METER MODE 5//////////////////////////////////  
  if( mode == 5 )
   
{
 lcd.setCursor(0, 0);
 lcd.print("INDUCTOR METER  "); 
}

 //////////////////////////////// CONTINUITY MODE 6//////////////////////////////////  
  if( mode == 6 )
   
{
 lcd.setCursor(0, 0);
 lcd.print("CONTINUITY TEST"); 
 raw = analogRead(DL);
      buffer = raw * Vin;
      Vout = (buffer) / 1024.0;
      buffer = (Vin / Vout) - 1;
      R22 = R11 * buffer;
       lcd.setCursor(0, 1);
 lcd.print("CONTUINTY="); 
 lcd.print(R22,1);
}

 //////////////////////////////// DOIDE AND LED MODE 7//////////////////////////////////  
  if( mode == 7 )
   
{
 lcd.setCursor(0, 0);
 lcd.print(" DOIDE AND LED  "); 
  DLvalue = analogRead(DL);
DLvout = (DLvalue * 5.0) / 1024.0; // see text
DLvout = 5 - DLvout;
 lcd.setCursor(0, 1);
 lcd.print("DOIDE="); 
 lcd.print(DLvout,1);
}

 //////////////////////////////// FREQUNCY METER MODE 8//////////////////////////////////  
  if( mode == 8 )
   
{
 lcd.setCursor(0, 0);
 lcd.print(" FREQUNCY METER "); 
}

   //////////////////////////////// HFE METER 9//////////////////////////////////  
  if( mode == 9 )
   
{
 lcd.setCursor(0, 0);
 lcd.print("  HFE  METER    "); 
}

 //////////////////////////////// CAPACITPR METER MODE 10//////////////////////////////////  
  if( mode == 10 )
   
{
 lcd.setCursor(0, 0);
 lcd.print(" CAPACITOR METER ");
    
    lcd.setCursor(15,1); 
  lcd.print("*");
  if(mk==0){
    pinMode(8,OUTPUT);
    pinMode(9,INPUT);
    digitalWrite(8,HIGH);
  }

  if(mk==1){
    pinMode(9,OUTPUT);
    pinMode(8,INPUT);
    digitalWrite(9,HIGH);
  }

  time0=micros();
  while(analogRead(cap)<644){
    time2=micros()-time0;
    if(time2>=1000000 && mk==0){
      mk=1;
      time0=100000000;
      break;
    }
  }

  time1=micros()-time0; 

  while(analogRead(cap)>0){ 
    pinMode(9,OUTPUT); 
    pinMode(8,OUTPUT); 
    digitalWrite(9,LOW); 
    digitalWrite(8,LOW);
  }

  if(mk==1&&time1<1000){
    mk=0;
  }

  lcd.setCursor(1,1);
  c=time1;
  c=c/1000-null0;
  c=abs(c);

  if(time1>=10000000){
    lcd.setCursor(1,1);
    lcd.print(" TEST uF   "); 
  }
  else{
    lcd.print(c); 

    if(mk==0){
      lcd.print(" nF       ");
    }
    if(mk==1){
      lcd.print(" uF       ");
    }
  }
  if(i==0){
    i++;
    null0=c+0.02;
  }
  delay(100);  
    
    
}

} // END LOOP