Night Light with Button

/*
 * Atiriya Iyer
 * Photocell Tests
 * 6-15-17
 * Version 2
 */

const int pinPhoto= A0;
int lightLevel =0;
const int pinLEDblue= 9;
const int pinLEDgreen= 10;
const int pinLEDred= 11;
const int pinButton=2;
int brightness= 0;
int lastButt= 0;
int newButt= 0;
unsigned long timeStart= 0; //long can hold a much larger number and unsigned is only positive
int minimum= 5000;
int maximum= -5000;


void setup()
{
  // put your setup code here, to run once:
  pinMode (pinPhoto, INPUT);
  pinMode (pinLEDblue, OUTPUT);
  pinMode (pinLEDgreen, OUTPUT);
  pinMode (pinLEDred, OUTPUT);
  pinMode (pinButton, INPUT);

  Serial.begin (9600);

  analogWrite (pinLEDblue, 255);
  delay(500);
  analogWrite (pinLEDblue, 0);
  delay(500);
  analogWrite (pinLEDgreen, 255);
  delay(500);
  analogWrite (pinLEDgreen, 0);
  delay(500);
  analogWrite (pinLEDred, 255);
  delay(500);
  analogWrite (pinLEDred, 0);
}

void loop()
{
  // put your main code here, to run repeatedly:
  lightLevel= analogRead (pinPhoto);
  brightness= map(lightLevel, minimum, maximum, 255, 0);
  //established proportions, uses values we know to values we need
  brightness= constrain(brightness, 0,255);

  analogWrite (pinLEDblue, brightness);
  analogWrite (pinLEDred, brightness);

  //if (brightness > minimum && brightness < (maximum-minimum)/5)
 // {
    //analogWrite (pinLEDgreen, 50/255*brightness);
    //analogWrite (pinLEDred, 50/255*brightness);
    //analogWrite (pinLEDblue, 255/255*brightness);
  //}

  // analogWrite (pinLEDblue, brightness/2);
  // analogWrite (pinLEDred, brightness/2);
  // analogWrite (pinLEDgreen, brightness/2);

  newButt= debounce(lastButt);
  if (newButt== HIGH && lastButt== LOW)
  {
    Serial.println("Calibrating...");
    calibrate();
  }
  lastButt= newButt;

  Serial.print ("Light level= ");
  Serial.println (lightLevel);
  Serial.print ("brightness= ");
  Serial.println (brightness);
}

boolean debounce (boolean last)
{
  boolean current = digitalRead(pinButton);
  if (last != current)
  {
    delay(5);
    current= digitalRead(pinButton);
  }
  return current;
}

void calibrate()
{
  analogWrite (pinLEDred, 255);
  analogWrite (pinLEDblue, 0);
  analogWrite (pinLEDgreen, 0);
  delay (200);
  analogWrite (pinLEDred, 0);
  analogWrite (pinLEDblue, 0);
  analogWrite (pinLEDgreen, 0);

  timeStart= millis();
  while (millis()-timeStart < 5000)
  {
    lightLevel= analogRead (pinPhoto);
    if (lightLevel > maximum)
    {
      maximum= lightLevel;
    }
    else if (lightLevel < minimum)
    {
      minimum= lightLevel;
    }
  }
  Serial.println (maximum);
  Serial.println (minimum);

  analogWrite (pinLEDred, 160);
  analogWrite (pinLEDblue, 0);
  analogWrite (pinLEDgreen, 100);
  delay (200);
  analogWrite (pinLEDred, 0);
  analogWrite (pinLEDblue, 0);
  analogWrite (pinLEDgreen, 0);
}