This sketch implements a simple line sensor for the Arduino

line_sensor.ino

// Line Sensor Breakout - Analog
int out;

void setup()
{
	Serial.begin(9600); // sets the serial port to 9600
}

void loop()
{
	out = analogRead(0); // read analog input pin 0
	Serial.println(out, DEC); // print the value of the sensor
	delay(100); // wait 100ms for next reading
}