#define segA 2
#define segB 3
#define segC 4
#define segD 5
#define segE 6
#define segF 7
#define segG 8
#define DP 9
#define up_button 13
#define down_button 12
int up_state  , down_state , level; 
void setup() {
  Serial.begin(9600) ; 
pinMode(up_button , INPUT);
pinMode(down_button , INPUT_PULLUP);
for(int pin=2 ; pin<=9 ;pin++)
{
pinMode(pin , OUTPUT);
}
}

void loop() {
  
  up_state = digitalRead(up_button) ; 
  down_state = ! digitalRead(down_button) ; 

  if(up_state == 1 && level < 9 )
  {
    level = level + 1 ; // level++ level+=1
    delay(1000) ; 
  }
  if(down_state == 1 && level > 0)
  {
    level-=1 ; 
    delay(1000) ; 
  }
  switch (level){
    case 0 : zero() ; break ; 
    case 1 : one() ; break ; 
    case 2 : two() ; break ; 
    case 3 : three() ;break ;
    case 4 : four() ; break ; 
    default : clear() ; 
  }

  Serial.println("level :"+String(level));
  delay(50) ; 

}


void zero(){
    clear() ; 
  for(int pin=2 ; pin<=9 ;pin++)
{
  if(pin != 8)
  {
    digitalWrite(pin, HIGH) ; 
  }
}
}


void one()
{  clear() ; 
  digitalWrite(segB , HIGH);
  digitalWrite(segC , HIGH);
}

void two(){
    clear() ; 
  for(int pin=2 ; pin<=9 ;pin++)
{ if(pin != 4  &&  pin!= 7)
{
  digitalWrite(pin, HIGH) ; 
  }
}
}
void three(){
    clear() ; 
  for(int pin=2 ; pin<=9 ;pin++)
{ if(pin != 6  &&  pin!= 7)
{
  digitalWrite(pin, HIGH) ; 
  }
}
}
void four(){
    clear() ; 
  for(int pin=2 ; pin<=9 ;pin++)
{ if(pin != 2  &&  pin!= 5 && pin!= 6)
{
  digitalWrite(pin, HIGH) ; 
  }
}
}



void test_display(){
  for(int pin=2 ; pin<=9 ;pin++)
{
  digitalWrite(pin, HIGH) ; 
}
}
void clear(){
  for(int pin=2 ; pin<=9 ;pin++)
{
  digitalWrite(pin, LOW) ; 
}
}