跑马灯程序

void setup() {
// put your setup code here, to run once:
int i;
for(i = 7;i <= 12;i++){
pinMode(i,OUTPUT);
}

}
int now=  7;
int mode = 0;
void loop() {
// put your main code here, to run repeatedly
if(mode == 0){
int i;
for(i = 7;i <= 12;i++){
digitalWrite(i,LOW);
}
digitalWrite(now,HIGH);
delay(200);
now++;
if(now > 12){now = 12;mode = 1;}

}
else if (mode == 1)
{
int i;
for(i = 7;i <= 12;i++){
digitalWrite(i,LOW);
}
digitalWrite(now,HIGH);
delay(200);
now--;
if(now < 7){now = 7;mode = 0;}

}

}