Arduino 單個按鍵控制led燈閃爍、常亮、關閉

int ledpin = 12;  //led輸出
int inpin = 7;   //按鍵輸入
int val;        //全局變量
int x = 0;      //全局變量

void setup() {
  pinMode(ledpin,OUTPUT);
  pinMode(inpin,INPUT);
}

void loop() {
  val = digitalRead(inpin);  //讀取按鍵輸入量
   if(val == HIGH){            //如果按下
     delay(1500);             //延1.5S
     val = digitalRead(inpin); 
     if(val == HIGH){         //如果任為按下
       while(x == 0){         //長1.5 led燈閃爍
         digitalWrite(ledpin,HIGH);
         delay(500);
         digitalWrite(ledpin,LOW);
         delay(500);
         val = digitalRead(inpin);
         if(val == HIGH){
           x=1;
           break;       //跳出循環
         }
       }
     }
     else if (x == 0){
       digitalWrite(ledpin,HIGH);
       x = 1;
       delay(500);
      }
     else if (x == 1){
       digitalWrite(ledpin,LOW);
       x = 0;
       delay(500);
      }
    }
 
}