LOFR

#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2);
int inbutton = 9;
int buttonstate = LOW;
int lastbuttonstate = HIGH;
int actual;
int trigpin = A4;
int echopin = A5;
int aPinIn = A0;
int val = 0; 
float Vout = 0.0;
float Vin = 4.66; 
float Rknown = 10000.0; 
float Runknown = 0.0;
float U = 0.0;
float I = 0.0; 
int backlight = 13;
int analogPin = 1; 
int chargePin = 6;      
int dischargePin = 7;  
float resistorValue = 1000.0;   
unsigned long startTime;
unsigned long elapsedTime;
float microFarads;              
float nanoFarads;
float picoFarads;

void setup(){
 pinMode(inbutton, INPUT);
 digitalWrite(inbutton, HIGH);
 lcd.begin(16, 2);
 pinMode(backlight, OUTPUT);
 pinMode(chargePin, OUTPUT);   
 digitalWrite(chargePin, LOW); 
 pinMode(trigpin, OUTPUT);
 pinMode(echopin, INPUT);
 digitalWrite(backlight, HIGH);
} 



void loop()
{
    buttonstate = digitalRead(inbutton);
if (buttonstate == HIGH && buttonstate != lastbuttonstate)
    {
      if(actual == 3) actual = 0;
      else actual++;
    }
  lastbuttonstate = buttonstate;
 
  switch(actual)
  {
    case 0:
    range();
    break;

    case 1:
    ohm();
    break;

    case 2:
    farad();
    break;

   }
}

void range() {
  float duration; 
  float cm;
  pinMode(trigpin, OUTPUT);
  digitalWrite(trigpin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigpin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigpin, LOW);

  pinMode(echopin, INPUT);
  duration = pulseIn(echopin, HIGH);
 
  cm = microsecondsToCentimeters(duration);
  
  if (cm > 500){
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Out of Range");
    delay(500);
  }
  
  else {

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("The object is");
  lcd.setCursor(0, 1);
  lcd.print(cm);
  lcd.print(" cm far");
  delay(500);
  }
 }
float microsecondsToCentimeters(float microseconds){
return microseconds / 29 / 2;
}

 

void ohm(){
lcd.clear();
 val = analogRead(aPinIn);
 Vout = (Vin/1024.0) * val;
 U = (Vin - Vout);
 I = (U/Rknown);
 Runknown = (Vout/I);
 lcd.print("Vout: ");
 lcd.print(Vout);
lcd.setCursor(0, 1); 
 lcd.print("R: ");
 lcd.print(Runknown);
 delay(1000);
}


 void farad(){
   digitalWrite(chargePin, HIGH);  
   startTime = millis();
   while(analogRead(analogPin) < 648){ 
   }
   elapsedTime= millis() - startTime; 
   microFarads = ((float)elapsedTime / resistorValue) * 1000;
    
   if(elapsedTime == 0){
     lcd.clear();
     lcd.print("Insert a");
     lcd.setCursor(0, 1);
     lcd.print("Capacitor");     
     delay(1000);
   }
   if (microFarads >= 1){
     lcd.clear();
     lcd.setCursor(0,0);
     lcd.print((long)microFarads);   
     lcd.print("  microFarad");    
     lcd.setCursor(0,0);
   }
   else if (microFarads <= 1){

     nanoFarads = microFarads * 1000.0; 
     lcd.clear();
     lcd.setCursor(0,0);                                  
     lcd.print((long)nanoFarads); 
     lcd.print("  nanoFarad");  
     lcd.setCursor(0,0);
   }
   if (nanoFarads >= 1){
     picoFarads = nanoFarads * 1000.0; 
     lcd.clear();
     lcd.setCursor(0,0);                                  
     lcd.print((long)picoFarads);
     lcd.print("  picoFarad");  
     lcd.setCursor(0,0);
   }
 
   digitalWrite(chargePin, LOW);   
   pinMode(dischargePin, OUTPUT);   
   digitalWrite(dischargePin, LOW); 
   while(analogRead(analogPin) > 0){
                                    
   }
   pinMode(dischargePin, INPUT);   

 }