Make Your Own Stopwatch With Arduino

/*Simple LCD stopwatch program with stop, start, reset and lap buttons.*/

//including liblary for LCD
#include <LiquidCrystal.h> 

//setting up LCD INPUT pins
LiquidCrystal lcd(12,11,10,9,8,7);// (RS,E D4,D5,D6,D7)

//setting hours, minutes, secound and miliseconds to 0
int h=0;     
int m=0;     
int s=0;     
int ms=0;    

//defines pin for all buttons
const int startPin = 3;    
const int stopPin = 4;    
const int resetPin = 5;   
    
//defines starting points
int start=0;     
int stop1=0;
int reset=0;


void stopwatch()
{
             
  lcd.setCursor(3,0);   //setting start point on lcd 
  lcd.print("TIME:");   //display TIME
  lcd.print(h);         //display hours
  lcd.print(":");      
  lcd.print(m);         //display minutes
  lcd.print(":"); 
  lcd.print(s);         //display seconds
  lcd.setCursor(3,1);
  lcd.print("         ");
 
  ms=ms+10;           
  delay(10); 
   
 if(ms==590)           
  {
   
   ms=0; 
   s=s+1; 
  }
  
  if(s==60)     //if state for counting up minutes
  { 
  s=0; 
  m=m+1; 
  }

  if(m==60)      //if state for counting up hours
  {  
  m=00; 
  h=h+01;  
  } 
   
   

   stop1 = digitalRead(stopPin);  //reading buton state
 if(stop1 == HIGH)    //checking if button is pressed
 {
  stopwatch_stop();   //calls the stopwatch_stop function
 }
  else
  {
   stopwatch();    //calls the stopwatch function
  }
}

void stopwatch_stop()
{
  lcd.setCursor(3,0); 
  lcd.print("TIME:"); 
  lcd.print(h); 
  lcd.print(":"); 
  lcd.print(m); 
  lcd.print(":"); 
  lcd.print(s);
  lcd.setCursor(3,1);
  lcd.print("         ");
      
    
   start = digitalRead(startPin);   //reading buton state
 if(start == HIGH)
 {
  stopwatch();    //calls the stopwatch function
 } 
 
 reset = digitalRead(resetPin);   //reading buton state
 if(reset == HIGH)
 {
   stopwatch_reset();    //calls the stopwatch_reset function
   loop();
  }
 if(reset == LOW)
 {
  stopwatch_stop();    //calls the stopwatch_stop function
 }
}

void stopwatch_reset()
{
 lcd.clear();
 h=00;    //seting hours to 0
 m=00;    //seting minutes to 0
 s=00;    //seting seconds to 0
 return;  //exiting the program and returning to the point where entered the program
}




void setup() 
{ 
  
  
  lcd.begin(16 ,2);  //starting LCD
   
  //defining pins if they are INPUT or OUTPUT pins
  pinMode(startPin, INPUT);  
  pinMode(stopPin, INPUT);
  pinMode(resetPin, INPUT);
  
} 
void loop() 
{ 
  
  lcd.setCursor(3,1); 
  lcd.print("STOPWATCH");  
  lcd.setCursor(3,0);  
  lcd.print("TIME:"); 
  lcd.print(h); 
  lcd.print(":"); 
  lcd.print(m); 
  lcd.print(":"); 
  lcd.print(s);
  
 start = digitalRead(startPin); //reading buton state
 if(start == HIGH) 
 {
  stopwatch();  //calls the stopwatch function
 }
}