#include <LiquidCrystal.h>

const int rs = 2, en = 3, d4 = 4, d5 = 5, d6 = 6, d7 = 7;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

int cs = 9;
const int contrast = 100;

int h = 12;
int m = 59;
int s = 45;
int flag = 1;

int button1;
int button2;

int hs = 0;
int ms = 1;

const int Time_light = 150;
int bl_T0 = Time_light;
int bl = 10;
const int backlight = 120;

static uint32_t last_time, now = 0;

void setup(){
  lcd.begin(16, 2);
  pinMode(hs, INPUT_PULLUP);
  pinMode(ms, INPUT_PULLUP);
  analogWrite(cs, contrast);
  analogWrite(bl, backlight);
  now = millis();
}

void loop(){
  lcd.begin(16, 2);
  lcd.setCursor(0,0 );
  lcd.print("Time");
  if(h<10)lcd.print("0");
  lcd.print(h);
  lcd.print(":");
  if(m<10)lcd.print("0");
  lcd.print(m);
  lcd.print(":");
  if(s<10)lcd.print("0");
  lcd.print(s);

  if(flag==0) lcd.print(" AM");
  if(flag==1) lcd.print(" PM");

  lcd.setCursor(0, 1);
  lcd.print("Precision clock");

  for (int i = 0; i<5; i++){
    while((now-last_time)<200){
      now = millis();
    }

    last_time = now;

    button1 = digitalRead(hs);
    button2 = digitalRead(ms);

    bl_T0--;
    if (bl_T0 == 0){
      analogWrite(bl, 0);
      bl_T0++;
    }

    if(((button1==0)|(button2==0))&(bl_T0==1)){
      bl_T0=Time_light;
      analogWrite(bl, backlight);

      while((button1==0)|(button2==0)){
        button1 = digitalRead(hs);
        button2 = digitalRead(ms);
      }
    }
    else{
      if(button1==0){
        h=h+1;
        bl_T0=Time_light;
        analogWrite(bl, backlight);
      }
      if(button2==0){
        s=0;
        m=m+1;
        bl_T0=Time_light;
        analogWrite(bl, backlight);
      }

      if(s==60){
        s=0;
        m=m+1;
      }
      if(m==60){
        m=0;
        h=h+1;
      }
      if(h==13){
        h=1;
        flag=flag+1;
        if(flag==2)flag=0;
      }
      
      if((button1==0)|(button2==0)){
        lcd.setCursor(0,0);
        lcd.print("Time ");
        if(h<10)lcd.print("0");
        lcd.print(h);
        lcd.print(":");
        if(m<10)lcd.print("0");
        lcd.print(m);
        lcd.print(":");
        if(s<10)lcd.print("0");
        lcd.print(s);

        if(flag==0)lcd.print(" AM");
        if(flag==1)lcd.print(" PM");

        lcd.setCursor(0,1);
        lcd.print("Precision clock");
      }
    }
  }

  s=s+1;

  if(s==60){
    s=0;
    m=m+1;
  }
  if(m=60){
    m=0;
    h=h+1;
  }
  if(h==13){
    h=1;
    flag=flag+1;
    if(flag==2)flag=0;
  }
}