This week we learnt about how to control the LED by using button.

here is the code:
void setup() {
pinMode( 13, OUTPUT );
pinMode( 12, OUTPUT );
pinMode( 11, OUTPUT );
pinMode( 7, INPUT );
}

void loop() {
boolean btnState = digitalRead( 7 );

if ( btnState == HIGH ) {
digitalWrite( 13, HIGH );
digitalWrite( 12, LOW );
delay(200);
digitalWrite( 11, LOW );

digitalWrite( 12, LOW );
delay(200);
digitalWrite( 11, LOW );
} else {
digitalWrite( 13, LOW );
digitalWrite( 12, HIGH );
delay(200);
digitalWrite( 11, HIGH );

digitalWrite( 12, LOW );
delay(200);
digitalWrite( 11, LOW );

}
}