/**
 * Configure the rotary encoder pins
 */
#define ENCODER_CLK 5
#define ENCODER_DT  3

void setup() {
  Serial.begin( 9600 );

  // Setup rotary encoder pins
  pinMode( ENCODER_CLK, INPUT );
  pinMode( ENCODER_DT, INPUT );
}

/**
 * Global variables
 */
int lastClk    = HIGH;
bool systemOn  = false;
int targetTemp = 20;

/**
 * Handles rotations on the rotary encoder
 */
void handleRotaryEncoder() {
  int newClk = digitalRead( ENCODER_CLK );
  if ( newClk != lastClk ) {
    lastClk = newClk;
    int dtValue = digitalRead( ENCODER_DT );

    if ( newClk == LOW && dtValue == HIGH && targetTemp >= 1 )
      targetTemp--;

    if ( newClk == LOW && dtValue == LOW && targetTemp < 100 )
      targetTemp++;
  }
}

void loop() {
  handleRotaryEncoder();
  Serial.println(targetTemp);
}