Mega 2560

Why Arduino can't recognize my Arduino Mega 2560?

Would you care to expand on that (a lot) !

There is not enough information to give any sort of answer.

/* Three Colour Traffic Light With Barrier*/

// Number of pins connected to Traffic leds :

const int traffic_red = 12;
const int traffic_orange= 11;
const int traffic_green = 10;

// Number of pins connected to Pedestrian leds:

const int pedestrian_red = 9;
const int pedestrian_green= 8 ;

// The number of push button pin :

const int button_pin = 2;

// Variable for reading the push button state:

int button_state = 0;

// Setup loop will run once:

void setup()
{

// Initializing traffic leds as an output:
pinMode(traffic_red , OUTPUT );
pinMode(traffic_orange , OUTPUT );
pinMode(traffic_green , OUTPUT );

// Initializing pedestrian leds as an output:

pinMode(pedestrian_red , OUTPUT ); pinMode(pedestrian_green ,OUTPUT );

// Initializing push button pin as an input:

pinMode(button_pin , INPUT );

}

// void loop will run repeatedly:

void loop()
{

// Read the state of button_pin :
button_state=digitalRead(button_pinn);

// If the push button is pressed then button_state is equal to HIGH and if block will execute:

if(button_state ==HIGH )
{
digitalWrite( traffic_green , HIGH); // Green light of traffic will glow:
digitalWrite(pedestrian_red , HIGH); // Red light of pedestrian light will also glow:
delay(3000); // These lights glow for 3 seconds:
digitalWrite( traffic_green , LOW); // Green light of traffic will turn off:

digitalWrite( traffic_orange , HIGH);// Orange light of traffic will glow:
delay(1000); // Orange light will glow for 1 second:
digitalWrite( traffic_orange , LOW); // Orange light will turn off:
digitalWrite( pedestrian_red, LOW);// Red light of pedestrian will turn off:

digitalWrite( traffic_red , HIGH);// Red light of traffic will glow:
digitalWrite( pedestrian_green , HIGH); // Green light of pedestrian will glow:
delay(5000); // Both lights will glow for 5 seconds:
digitalWrite( traffic_red , LOW); // Red light of traffic will turn off:
digitalWrite (pedestrian_green, LOW); // Green light of pedestrian will turn off:

}

// If the push button is not pressed,then else block will execute:
else{

digitalWrite( traffic_green , HIGH); // Green light of traffic will glow:
delay(3000); // Green light will glow for 3 seconds:
digitalWrite(traffic_green , LOW); // Green light will turn off:

digitalWrite( traffic_orange , HIGH);// Orange light of traffic will glow;
delay(1000); // Light will glow for 1 second:
digitalWrite(traffic_orange , LOW); // Orange light will turn off:

digitalWrite( traffic_red , HIGH);// Red light of traffic will glow:
delay(3000); // Light will glow for 3 seconds:
digitalWrite(traffic_red , LOW); // Red light of traffic will turn off:

}

}

better use

const byte instead of const int

and

bool button_state instead of int button_state