#include <Servo.h>
int red=4;
int yellow=5;
int blue=6;

Servo s1;

void setup() 
{
s1.attach(3);
pinMode(red, OUTPUT);
pinMode(yellow, OUTPUT);
pinMode(blue, OUTPUT);

digitalWrite(red, HIGH);
digitalWrite(yellow, HIGH);
digitalWrite(blue, HIGH);
}

void loop() 
{
s1.write(0);    
digitalWrite(red, LOW);
delay(1000);
digitalWrite(red, HIGH);

s1.write(90);   
digitalWrite(yellow, LOW);
delay(1000);
digitalWrite(yellow, HIGH);

s1.write(180);  
digitalWrite(blue, LOW);
delay(1000);
digitalWrite(blue, HIGH);

s1.write(90);   
digitalWrite(yellow, LOW);
delay(1000);
digitalWrite(yellow, HIGH);
}

/*#include <Servo.h>
Servo s1;

void setup() 
{
s1.attach(3);
}

void loop() 
{
for(int i=0; i<=180; i++)
{
  s1.write(i);
  delay(150);
}
for(int i=180; i>=0; i--)
{
  s1.write(i);
  delay(150);
}
}*/