Ex 1.1

// Exercise 1.1

int del=100; // sets a default delay time, 1000 milliseconds (one second)
void setup()
{
	// initialize the digital pins as outputs:
	for (int i = 2; i<=9 ; i++)
	{
		pinMode(i, OUTPUT);
	} // end of for loop
} // end of setup

void loop()
{
	for (int i = 2; i<=9; i++) // blink from LEDs 2 to 9
	{
		digitalWrite(i, HIGH);
		delay(del);
		digitalWrite(i, LOW);
	}
	for (int i = 8; i>=3; i--) // blink from LEDs 8 to 3
	{
		digitalWrite(i, HIGH);
		delay(del);
		digitalWrite(i, LOW);
	}
}