#define A0IN 0
#define A1IN 1

int analogamount = 0;  // used to convert voltage left bridge
int analogamount1 = 0; // used to convert voltage right bridge

float voltage =  0; // left bridge voltage
float voltage1 = 0; // right bridge voltate
float voltage2 = 0; // used for voltage correction 

float answer = 0;
int cv = 0;       // counter variable used screen drawing

void setup() {
   analogReference(EXTERNAL);   // use AREF for reference voltage
   Serial.begin(9600);
   set_screen();
}

void loop() {
  
  analogamount = analogRead(A0IN);
  analogamount1 =analogRead(A1IN);
   
  voltage=analogamount * (4500 / 1023.00); 
  
  voltage1=analogamount1 * (4500 / 1023.00); 
  
  voltage2 = 0;

set_xy(23,1); 
save_cursor_pos();

if(voltage == voltage1) { 
  set_xy(10,25);
  repeat_char(10,0x20); 
  set_xy(10,47);
  repeat_char(10,0x20); 
  set_xy(14,49);
  repeat_char(10,0x20);

} else {

set_xy(10,25);
voltage = round(voltage);
voltage = voltage * .001;
Serial.print(voltage);
if( voltage < 1) { Serial.print("mV"); } else { Serial.print("V ");}

set_xy(10,47);
voltage1 = voltage1 * .001;
Serial.print(voltage1);
if( voltage1 < 1) { Serial.print("mV"); } else { Serial.print("V ");}

set_xy(14,49);
voltage2 = voltage * 2;
answer =   10000 * voltage1 / (voltage2 - voltage1);
answer = round(answer);
Serial.print( (int) answer);  
Serial.print(" Ohms     ");  
}

restore_cursor_pos();
delay(3000);
}

void save_cursor_pos(){
   Serial.print("\x1B" "[s"); //  save cursor position     
}

void restore_cursor_pos(){
   Serial.print("\x1B" "[u"); //  restore cursor position     
}

void repeat_char(int r,char c){
  int rx;
  for(rx = 0; rx != r; rx++){
    Serial.print(c);
  }
}

void set_xy(int x, int y){
  Serial.print("\x1B[");
  Serial.print(x);
  Serial.print(";");  
  Serial.print(y);
  Serial.print("H");  
}

void set_screen(){
   Serial.print("\x1B" "[2J"); 
   set_xy(1,2);
   Serial.print("Ohmmeter");
   set_xy(3,2);
   Serial.print("\xDA");
   repeat_char(20,0xc4);
   Serial.print("\xC2");
   repeat_char(20,0xc4);
   Serial.print("\xBF");
   set_xy(4,2);
   for(cv = 0; cv != 2; cv++){
      Serial.print("\xB3");
      repeat_char(20,0x20);
      Serial.print("\xB3");
      repeat_char(20,0x20);
      Serial.println("\xB3");
      Serial.print(" ");
   }      
   set_xy(6,2);
   for(cv = 0; cv != 3; cv++){
      Serial.print("\xB3");
      repeat_char(20,0x20);
      Serial.print("\xB2");
      repeat_char(20,0x20);
      Serial.println("\xB2");
      Serial.print(" ");
   }   
   set_xy(7,25);
   Serial.print("R1 (10K)");
   set_xy(9,1);
   Serial.print("\xC4\xC1\xC4");
   repeat_char(19,0x20);
   Serial.print("\xB3");
   repeat_char(20,0x20);
   Serial.print("\xB3");
   set_xy(10,1);
   Serial.print("\x1B[10;1H" " \xC4 ");
   repeat_char(19,0x20);
   Serial.print("\xB3");
   repeat_char(20,0x20);
   Serial.print("\xB3");
   set_xy(11,1);
   Serial.print("\xC4\xC4\xC4");
   repeat_char(19,0x20);
   Serial.print("\xB3");
   repeat_char(20,0x20);
   Serial.print("\xB3");
   set_xy(12,2);
   Serial.print("\xC2 ");
   repeat_char(19,0x20);
   Serial.print("\xB3");
   repeat_char(20,0x20);
   Serial.print("\xB3");
   set_xy(13,2);
   for(cv = 0; cv != 3; cv++){
      Serial.print("\xB3");
      repeat_char(20,0x20);
      Serial.print("\xB2");
      repeat_char(20,0x20);
      Serial.println("\xB2");
      Serial.print(" ");
   }
   set_xy(16,2);
   for(cv = 0; cv != 3; cv++){
      Serial.print("\xB3");
      repeat_char(20,0x20);
      Serial.print("\xB3");
      repeat_char(20,0x20);
      Serial.println("\xB3");
      Serial.print(" ");
   }
   set_xy(18,2);
   Serial.print("\xC0");
   repeat_char(20,0xc4);
   Serial.print("\xC1");
   repeat_char(20,0xc4);
   Serial.print("\xD9");
   set_xy(7,46);
   Serial.print("R2 (10K)");
   set_xy(14,25);
   Serial.print("R3 (10K)");
   set_xy(14,46);
   Serial.print("Rx");   
}