Digital Input controlling Digital output

This example was written to control a motor from a touch sensor. More generically, it turns on a digital output based on the state of a digital input.

/*
  Digital Input controlling DC Motor
 by Tom Igoe 
 
 This example controls a DC motor on pin 13. If a digital input on pin 3
 is HIGH, the motor turns on.  Otherwise it turns off.  In the original 
 example, the digital input was connected to a QT113 capacitive touch sensor.
 
 Created 28 Jan. 2006 
 */


int motorPin = 13;        // this is the digital output pin for the motor
int touchSensorPin = 3;   // this is the digital input pin for the touch sensor
int touchSensor = 0;      // this is a variable to hold the state of the touch sensor


void setup() {
  pinMode(motorPin, OUTPUT);       // set the motor pin as a digital output
  pinMode(touchSensorPin, INPUT);  // set the touch sensor pin as a digital input
  blink(3);                        // blink the LED pin 3 times to know that Arduino is alive
}

void loop() {
  touchSensor = digitalRead(touchSensorPin);  // read the touch sensor
  if (touchSensor == HIGH) {                  // if the touch sensor is sending 5 volts
    digitalWrite(motorPin, HIGH);             // turn on the motor
  } 
  else {
    digitalWrite(motorPin, LOW);             // turn off the motor
  }
}