RFduino controller for power LED used inside a upcycled NIFE lamp

NIFE_lamp.ino

int ledPin = 6;
int btnPin = 2;

int state = 0;
int power = 0;
float diff = 0;
int steps = 30;
int statesArray[4] = {0, 85, 170, 255};

void setup() {
  pinMode(btnPin, INPUT);
  pinMode(ledPin, OUTPUT);

  // prepare wake on btn press
  RFduino_pinWake(btnPin, HIGH);
}

void btnReleased() {
  // cycle through 4 states on btn release
  state ++;
  if (state > 3) state = 0;
  // calculate step size, so transition between states always has same duratiob
  diff = (statesArray[state] - power) / steps;
}

void updatePower() {
  if (abs(statesArray[state] - power) > abs(diff)) {
    power += diff;
  } else if (abs(statesArray[state] - power) > 0) {
    power = statesArray[state];
  }

  analogWrite(ledPin, power);
}

void loop() {
  int isPressed = digitalRead(btnPin);

  if (!isPressed && statesArray[state] == power) {
    // good night
    RFduino_ULPDelay(INFINITE);
    // point of resume
    RFduino_resetPinWake(btnPin);
  }

  if (isPressed) {
    // wait for btn to be released
    while (digitalRead(btnPin)) {}
    btnReleased();
  }

  updatePower();

  delay(20);
}