message: blower speed controll demo
diff: http://www.arduino.cc/en/Tutorial/AnalogInOutSerial
  */
  -#DEFINE BLOWERSPD_PIN 3
  +#define BLOWERSPD_PIN 3
  +#define BLOWER_HIGH 65
  +#define BLOWER_LOW 50
  // These constants won't change. They're used to give names to the pins used:
  const int analogInPin = A0; // Analog input pin that the potentiometer is attached to
  @@ -29,6 +31,8 @@ const int analogOutPin = LED_BUILTIN; // Analog output pin that the LED is attac
  int sensorValue = 0; // value read from the pot
  int outputValue = 0; // value output to the PWM (analog out)
  +unsigned int cyclecounter = 0;
  +
  void setup() {
  // initialize serial communications at 9600 bps:
  Serial.begin(9600);
  @@ -51,4 +55,10 @@ void loop() {
  // wait 2 milliseconds before the next loop for the analog-to-digital
  // converter to settle after the last reading:
  delay(2);
  + if(cyclecounter%125 < 62) {
  + analogWrite(BLOWERSPD_PIN, BLOWER_LOW);
  + } else {
  + analogWrite(BLOWERSPD_PIN, BLOWER_HIGH);
  + }
  + cyclecounter++;
  }
  