宣告整數 有正整數 負整數 0~32767 -32768~-1

 int  start_time;

void setup()

{

  Serial.begin(9600);

  int i = 32767;

  int a, b, c, d, e, f, g;

  Serial.println(a = i + 1);//-32768

  Serial.println(a = i + 2);//-32767

  Serial.println(a = i + 3);//-32766

  Serial.println(a = i + 4);//-32768

  Serial.println(a = i + 5);//-32764

  Serial.println(a = i + 32767);//-2

  Serial.println(a = i + 32768);//-1

  Serial.println(a = i + 32769);//0

}

void loop()

{

}