// Arduino 程式控制(科學魔法車)實驗18
int a; // 宣告一個整數變數 a
void setup() {
  pinMode(2,OUTPUT);
  pinMode(3,OUTPUT);
  pinMode(4,OUTPUT);
  pinMode(5,OUTPUT); 
  // A5輸入腳可以不宣告(默認為輸入)
}

void loop() {
a=analogRead(A5);
if(a<=700)
{leftward();
delay(1000);
backward();
delay(1000);
rightward();
delay(1000);
backward();}
delay(1000);
else
{forward();}
}

void forward(){
digitalWrite(2, HIGH);
digitalWrite(3, LOW);
digitalWrite(4, HIGH);
digitalWrite(5, LOW);
}
void backward(){
digitalWrite(2, LOW);
digitalWrite(3, HIGH);
digitalWrite(4, LOW);
digitalWrite(5, HIGH);
}
void rightward(){
digitalWrite(2, HIGH);
digitalWrite(3, LOW);
digitalWrite(4, LOW);
digitalWrite(5, HIGH);
}
void leftward(){
digitalWrite(2, LOW);
digitalWrite(3, HIGH);
digitalWrite(4, HIGH);
digitalWrite(5, LOW);
}
void stopward(){
digitalWrite(2, LOW);
digitalWrite(3, LOW);
digitalWrite(4, LOW);
digitalWrite(5, LOW);
}