/********************************************************************************
* Binary watch software by: David DiPaola
********************************************************************************/

//Constants for digital I/O pins
int BUTTON = 0;
int LED0 = 1;
int LED1 = 2;
int LED2 = 3;
int LED3 = 4;
int LED4 = 5;
int LED5 = 6;

//Variables  
int seconds = 0;
int minutes = 0;
int hours = 0;
static unsigned long time = 0;  //This should be OK, even with function calls
int minuteDisplayTime = 0;  //How long the minute display has been on
int waitBetweenTime = 0;  //How long the blank between has been on
int hourDisplayTime = 0;  //How long the hour display has been on

void setup(){
  pinMode(BUTTON, INPUT);
  pinMode(LED0, OUTPUT);
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);
  pinMode(LED5, OUTPUT);
}

void loop(){
  if((millis() - time) > 999){
    time = millis();  //millis() will overflow after around 50 days. :/
    seconds++;
  }
  
  //Overflow compensation
  if(millis() < time){
    if(((((4294967295 - time) + 1) + millis()) - time) > 999){
        time = millis();
        seconds++;
    }
  }
      
  if(seconds > 59){
    minutes++;
    seconds = 0;
  }
  
  if(minutes > 59){
    hours++;
    minutes = 0;
  }
  
  if(hours > 23)
    hours = 0;
  
  if(digitalRead(BUTTON))
    displayMinutes();
  
  if((minuteDisplayTime != 0)&&((minuteDisplayTime - millis()) > 999)){
    minuteDisplayTime = 0;
    displayBlank();
  }

  if((waitBetweenTime != 0)&&((waitBetweenTime - millis()) > 499)){
    waitBetweenTime = 0;
    displayHours();
  }

  if((hourDisplayTime != 0)&&((hourDisplayTime - millis()) > 999)){
    hourDisplayTime = 0;
    drawBinary(0);
  }
}

void displayMinutes(){
  minuteDisplayTime = millis();
  drawBinary(minutes);
}

void displayBlank(){
  waitBetweenTime = millis();
  drawBinary(0);
}

void displayHours(){
  hourDisplayTime = millis();
  drawBinary(hours);
}

void drawBinary(int value){
  //Shut off all LEDs
  digitalWrite(LED0, LOW);
  digitalWrite(LED1, LOW);
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  digitalWrite(LED4, LOW);
  digitalWrite(LED5, LOW);

  //Display the converted binary number
  if((value - 32) >= 0)
    digitalWrite(LED5, HIGH);
  if((value - (32+16)) >= 0)
    digitalWrite(LED4, HIGH);
  if((value - (32+16+8)) >= 0)
    digitalWrite(LED3, HIGH);
  if((value - (32+16+8+4)) >= 0)
    digitalWrite(LED2, HIGH);
  if((value - (32+16+8+4+2)) >= 0)
    digitalWrite(LED1, HIGH);
  if((value - (32+16+8+4+2+1)) >= 0)
    digitalWrite(LED0, HIGH);
}