/*I N C L U D E S  |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/

#include <LiquidCrystal.h> 
#include "Wire.h" 
#define DS1307_I2C_ADDRESS 0x68 //Real Time Clock I2C Location

/*D E F I N E S  S E T U P  ||||||||||||||||||||||||||||||||||||||||||||||||||*/

#define BUTTON_ADC_PIN           A0  // A0 is the button ADC input
#define LCD_BACKLIGHT_PIN         8  // D3 controls LCD backlight
#define RIGHT_10BIT_ADC           0  // right
#define UP_10BIT_ADC            119  // up
#define DOWN_10BIT_ADC          315  // down
#define LEFT_10BIT_ADC          485  // left
#define SELECT_10BIT_ADC        770  // right
#define BUTTONHYSTERESIS         10  // hysteresis for valid button sensing window
#define BUTTON_NONE               0  // 
#define BUTTON_RIGHT              1  // 
#define BUTTON_UP                 2  // 
#define BUTTON_DOWN               3  // 
#define BUTTON_LEFT               4  // 
#define BUTTON_SELECT             5  // 
//some example macros with friendly labels for LCD backlight/pin control, tested and can be swapped into the example code as you like
#define LCD_BACKLIGHT_OFF()     digitalWrite( LCD_BACKLIGHT_PIN, LOW )
#define LCD_BACKLIGHT_ON()      digitalWrite( LCD_BACKLIGHT_PIN, HIGH )
#define LCD_BACKLIGHT(state)    { if( state ){digitalWrite( LCD_BACKLIGHT_PIN, HIGH );}else{digitalWrite( LCD_BACKLIGHT_PIN, LOW );} }

/*V A R I A B L E S |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/
int backlightcountdown = 1000;
String mainmenu="Auto";
int SR=360; //Sunrise start time in minutes
int SRch1=50; //Channel 1 strength 0-255
int SRch2=50; //Channel 2 strength 0-255
int SRch3=50; //Channel 3 strength 0-255
int SRch4=50; //Channel 4 strength 0-255
int SRramp=30; //Sunrise ramp time in minuntes
int DT=450;
int DTch1=255;
int DTch2=255;
int DTch3=255;
int DTch4=255;
int DTramp=30;
int SSt=1080;
int SStch1=50;
int SStch2=50;
int SStch3=50;
int SStch4=50;
int SStramp=30;
int ML=1260;
int MLch1=1;
int MLch2=1;
int MLch3=1;
int MLch4=1;
int MLramp=30;
int ST=1410;
int STch1=0;
int STch2=0;
int STch3=0;
int STch4=0;
int STramp=30;
float Ramppct=0;

int chan1=0;
int chan2=0;
int chan3=0;
int chan4=0;
float ch1target=0;
float ch2target=0;
float ch3target=0;
float ch4target=0;
int menulevel1=0;
int menulevel2=0;
int PWMchan1=9;
int PWMchan2=10;
int PWMchan3=6;
int PWMchan4=5;
int godefault=0;

byte buttonJustPressed  = false;         //this will be true after a ReadButtons() call if triggered
byte buttonJustReleased = false;         //this will be true after a ReadButtons() call if triggered
byte buttonWas          = BUTTON_NONE;   //used by ReadButtons() for detection of button events
int daybyminute = 1;       // Current timeof day in minutes
const int buttonPin = 41;  // The number of the pushbutton Digital pin

LiquidCrystal lcd(12,11,0,3,4,5);   // LCD: ( RS=12, E=11, D0, D3, D4, D5 )
//setup()
/*  R T C   C L O C K   D S 1 3 0 7  |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/
byte decToBcd(byte val)    // Convert normal decimal numbers to binary coded decimal
{
  return ( (val/10*16) + (val%10) );
}

byte bcdToDec(byte val)    // Convert binary coded decimal to normal decimal numbers
{
  return ( (val/16*10) + (val%16) );
}

void setDateDs1307(byte second, // 0-59
byte minute, // 0-59
byte hour, // 1-23
byte dayOfWeek, // 1-7
byte dayOfMonth, // 1-28/29/30/31
byte month, // 1-12
byte year) // 0-99
{
  Wire.beginTransmission(DS1307_I2C_ADDRESS);
  Wire.write(0);
  Wire.write(decToBcd(second)); // 0 to bit 7 starts the clock
  Wire.write(decToBcd(minute));
  Wire.write(decToBcd(hour));   // If you want 12 hour am/pm you need to set
  // bit 6 (also need to change readDateDs1307)
  Wire.write(decToBcd(dayOfWeek));
  Wire.write(decToBcd(dayOfMonth));
  Wire.write(decToBcd(month));
  Wire.write(decToBcd(year));
  Wire.endTransmission();
}


// Gets the date and time from the ds1307
void getDateDs1307(byte *second,
byte *minute,
byte *hour,
byte *dayOfWeek,
byte *dayOfMonth,
byte *month,
byte *year)
{
  // Reset the register pointer
  Wire.beginTransmission(DS1307_I2C_ADDRESS);
  Wire.write(0);
  Wire.endTransmission();

  Wire.requestFrom(DS1307_I2C_ADDRESS, 7);

  // A few of these need masks because certain bits are control bits
  *second = bcdToDec(Wire.read() & 0x7f);
  *minute = bcdToDec(Wire.read());
  *hour = bcdToDec(Wire.read() & 0x3f); // Need to change this if 12 hour am/pm
  *dayOfWeek = bcdToDec(Wire.read());
  *dayOfMonth = bcdToDec(Wire.read());
  *month = bcdToDec(Wire.read());
  *year = bcdToDec(Wire.read());
}



/* O N E S E C O N D |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/

void onesecond() //function that runs once per second while program is running
{
  byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
  getDateDs1307(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, &year);
  daybyminute = ((hour * 60) + minute); //converts time of day to a single value in minutes
  lcd.setCursor(0, 0);
  if(hour>0)
  {
    if(hour<=12)
    {
      lcd.print(hour, DEC);
    }
    else
    {
      lcd.print(hour-12, DEC);
    }
  }
  else
  {
    lcd.print("12");
  }
  lcd.print(":");
  if (minute < 10) {
    lcd.print("0");
  }
  lcd.print(minute, DEC);
  lcd.print(":");
  if (second < 10) {
    lcd.print("0");
  }
  lcd.print(second, DEC);
  if(hour<12)
  {
    lcd.print("am");
  }
  else
  {
    lcd.print("pm");
  }
  lcd.print(" ");
  delay(1000);
}
/* A U T O     |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/
void auto1()
{
  String timeslot = " " ;
  microsecond();
  if (daybyminute>=SR && daybyminute<DT){
    timeslot="Rise";
    Ramppct=1-(SR+SRramp-daybyminute)/SRramp;
    if (Ramppct<0) {
      Ramppct=1;
    }    
    ch1target=SRch1*Ramppct;
    ch2target=SRch2*Ramppct;
    ch3target=SRch3*Ramppct;
    ch4target=SRch4*Ramppct;
  }
  if (daybyminute>=DT && daybyminute<SS){
    timeslot="Day ";
    Ramppct=1-(DT+DTramp-daybyminute)/DTramp;
    if (Ramppct<0) {
      Ramppct=1;
    }    
    ch1target=DTch1*Ramppct;
    ch2target=DTch2*Ramppct;
    ch3target=DTch3*Ramppct;
    ch4target=DTch4*Ramppct;
  }
  if (daybyminute>=SSt && daybyminute<ML) {
    timeslot="Set ";
    Ramppct=1-(SSt+SStramp-daybyminute)/SStramp;
    if (Ramppct<0) {
      Ramppct=1;
    }    
    ch1target=SStch1*Ramppct;
    ch2target=SStch2*Ramppct;
    ch3target=SStch3*Ramppct;
    ch4target=SStch4*Ramppct;
  }
  if (daybyminute>=ML && daybyminute<ST) {
    timeslot="Moon";
    Ramppct=1-((ML+MLramp-daybyminute)/MLramp);
    if (Ramppct<0) {
      Ramppct=1;
    }    
    ch1target=MLch1*Ramppct;
    ch2target=MLch2*Ramppct;
    ch3target=MLch3*Ramppct;
    ch4target=MLch4*Ramppct;
  }
  if (daybyminute>=ST && daybyminute<DT) {
    timeslot="ZZzz";
    Ramppct=1-(ST+STramp-daybyminute)/STramp;
    if (Ramppct<0) {
      Ramppct=1;
    }    
    ch1target=STch1*Ramppct;
    ch2target=STch2*Ramppct;
    ch3target=STch3*Ramppct;
    ch4target=STch4*Ramppct;
  }

  if (ch1target>chan1) {
    chan1++ ; 
  }
  else if (ch1target<chan1) {
    chan1-- ; 
  }

  if (ch2target>chan2) {
    chan2++; 
  }
  else if (ch2target<chan2) {
    chan2--; 
  }

  if (ch3target>chan3) {
    chan3++; 
  }
  else if (ch3target<chan3) {
    chan3--; 
  }

  if (ch4target>chan4) {
    chan4++;
  }
  else if (ch4target<chan4) {
    chan4--; 
  }

  //  lcd.setCursor(0,0);
  //   printHMS(hour, minute, second);
  lcd.setCursor(0,1);
  lcd.print("   ");
  lcd.setCursor(0,1);
  lcd.print(map(chan1, 0, 255, 0, 100));
  lcd.setCursor(4,1);
  lcd.print("   ");
  lcd.setCursor(4,1);
  lcd.print(map(chan2, 0, 255, 0, 100));
  lcd.setCursor(8,1);
  lcd.print("   ");
  lcd.setCursor(8,1);
  lcd.print(map(chan3, 0, 255, 0, 100));
  lcd.setCursor(12,1);
  lcd.print("   ");
  lcd.setCursor(12,1);
  lcd.print(map(chan4, 0, 255, 0, 100));
  lcd.setCursor(16,1);
  lcd.print(timeslot);

  ledSetAll();

}
/* M A N U A L    |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/
void manual()
{
  byte button;
  int led_sel=0;
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("LFT/RT to choose");
  delay(2000);
  lcd.setCursor(0,0);
  lcd.print("UP/DN to change ");
  delay(1000);
  lcd.setCursor(0,0);
  lcd.print("Select to exit  ");
  lcd.setCursor(0,1);
  lcd.print(map(chan1, 0, 255, 0, 100));
  lcd.setCursor(4,1);
  lcd.print(map(chan2, 0, 255, 0, 100));
  lcd.setCursor(8,1);
  lcd.print(map(chan3, 0, 255, 0, 100));
  lcd.setCursor(12,1);
  lcd.print(map(chan4, 0, 255, 0, 100));
  lcd.blink();
  lcd.setCursor(0,1);
  button = ReadButtons();
  while (button!=BUTTON_SELECT) {
    if (button==BUTTON_RIGHT){
      led_sel++;
      if (led_sel>2){
        led_sel=3;
      }
    }
    if (button==BUTTON_LEFT){
      led_sel--;
      if (led_sel<1){
        led_sel=0;
      }
    }
    if (button==BUTTON_UP){
      switch (led_sel) {
      case 0:
        chan1++;
        if (chan1 > 255) chan1=255;  
        break;
      case 1:
        chan2++;
        if (chan2 > 255) chan2=255;  
        break;
      case 2:
        chan3++;
        if (chan3 > 255) chan3=255;  
        break;
      case 3:
        chan4++;
        if (chan4 > 255) chan4=255;  
        break;
      }
    }
    if (button==BUTTON_DOWN){
      switch (led_sel) {
      case 0:
        chan1--;
        if (chan1 < 0) chan1=0;  
        break;
      case 1:
        chan2--;
        if (chan2 < 0) chan2=0;  
        break;
      case 2:
        chan3--;
        if (chan3 < 0) chan3=0;  
        break;
      case 3:
        chan4--;
        if (chan4 < 0) chan4=0;  
        break;
      }
    }
    ledSetAll();
    lcd.clear();
    lcd.print(" Manual Control");
    lcd.setCursor(0,1);
    lcd.print(map(chan1, 0, 255, 0, 100));
    lcd.setCursor(4,1);
    lcd.print(map(chan2, 0, 255, 0, 100));
    lcd.setCursor(8,1);
    lcd.print(map(chan3, 0, 255, 0, 100));
    lcd.setCursor(12,1);
    lcd.print(map(chan4, 0, 255, 0, 100));
    lcd.setCursor(led_sel*4,1);
    delay(100);
    button = ReadButtons();
  }
  lcd.clear();
  lcd.noBlink();
}
/* C O N F I G U R E |||||||||||||||||||||||||||||||||||||||||||||||||||*/
void configure()
{
}
/* R E S E T |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/
void reset()
{
  byte button;
  byte timestamp;
  lcd.setCursor(0,0);
  lcd.print("  Reset Certain?");
  lcd.setCursor(0,1);
  lcd.print("       No       ");
  delay(500);
  godefault=0;
  while (menulevel1==3) {
    button = ReadButtons();
    switch( button )    {
    case BUTTON_NONE:
      {
        break;
      }
    case BUTTON_RIGHT:
      {
        lcd.setCursor(0,1);
        lcd.print("       Yes       ");
        godefault=1;
        delay(200);
        break;
      }
    case BUTTON_UP:
      {
        break;
      }
    case BUTTON_DOWN:
      {
        break;
      }
    case BUTTON_LEFT:
      {
        lcd.setCursor(0,1);
        lcd.print("       No       ");
        godefault=0;
        delay(200);
        break;
      }
    case BUTTON_SELECT:
      {
        lcd.setCursor( 0, 1 );
        if (godefault==0)
        {
          lcd.print("Reset Cancelled ");
          delay(1000);
        }
        else
        {
          lcd.print( "Factory Reset   " );   
          delay(1000);
          //SELECT is a special case, it pulses the LCD backlight off and on for demo
          digitalWrite( LCD_BACKLIGHT_PIN, LOW );
          delay( 150 );
          digitalWrite( LCD_BACKLIGHT_PIN, HIGH );   //leave the backlight on at exit
          delay( 150 );
          SR=360; //Sunrise start time in minutes
          SRch1=50; //Channel 1 strength 0-255
          SRch2=50; //Channel 2 strength 0-255
          SRch3=50; //Channel 3 strength 0-255
          SRch4=50; //Channel 4 strength 0-255
          SRramp=30; //Sunrise ramp time in minuntes
          DT=630;
          DTch1=255;
          DTch2=255;
          DTch3=255;
          DTch4=255;
          DTramp=30;
          SSt=1080;
          SStch1=50;
          SStch2=50;
          SStch3=50;
          SStch4=50;
          SStramp=30;
          ML=1260;
          MLch1=1;
          MLch2=1;
          MLch3=1;
          MLch4=1;
          MLramp=30;
          ST=1410;
          STch1=0;
          STch2=0;
          STch3=0;
          STch4=0;
          STramp=30;
          Ramppct=0;
        }
        menulevel1=0;
        LCD_BACKLIGHT(true);   //leave the backlight on at exit
        delay( 150 );
        break;
      }
    default:
      {
        break;
      }
    }
  } 
  lcd.setCursor(0,0);
  lcd.print("                ");
  lcd.setCursor(0,1);
  lcd.print("                ");
}

/* M E N U L E V E L     |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/
void menulevel()
{
  switch (menulevel1) {
  case 0:
    mainmenu="Auto";
    break;
  case 1:
    mainmenu="Manual";
    break;
  case 2:
    mainmenu="Setup";
    break;
  case 3:
    mainmenu="Reset";
    break;
  }
  lcd.setCursor(8, 0);
  lcd.print("      ");   
  lcd.setCursor(8, 0);
  lcd.print(mainmenu); 
}



/* M I C R O S E C O N D |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/

void microsecond() //function that pulls current time
{
  byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
  getDateDs1307(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, &year);
  daybyminute = ((hour * 60) + minute); //converts time of day to a single value in minutes
  lcd.setCursor(0, 0);
  if(hour>0)
  {
    if(hour<=12)
    {
      if(hour<10) {
        lcd.print(" ");
      }
      lcd.print(hour, DEC);
    }
    else
    {
      lcd.print(hour-12, DEC);
    }
  }
  else
  {
    lcd.print("12");
  }
  lcd.print(":");
  if (minute < 10) {
    lcd.print("0");
  }
  lcd.print(minute, DEC);
  // lcd.print(":");
  // if (second < 10) {
  //  lcd.print("0");
  // }
  // lcd.print(second, DEC);
  if(hour<12)
  {
    lcd.print("A");
  }
  else
  {
    lcd.print("P");
  }
  lcd.print(" ");
  delay(50);
}
// format hours, mins, secs into a readable time (24 hr format)
void printHMS (byte hr,
byte mn,
byte sec      //time to print
)  
{

  if(hr<10){
    lcd.print(" ");
  }
  lcd.print(hr, DEC);
  lcd.print(":");
  if(mn<10){
    lcd.print("0");
  }
  lcd.print(mn, DEC);
  lcd.print(":");
  if(sec<10){
    lcd.print("0");
  }
  lcd.print(sec, DEC);
}

/* L E D  S E T  A L L ||||||||||||||||||||||||||||||||||||||||||||||||||*/
void ledSetAll(){
  analogWrite(PWMchan1,chan1);
  analogWrite(PWMchan2,chan2);
  analogWrite(PWMchan3,chan3);
  //  analogWrite(PWMchan4,chan4);
}
/* S E T U P  |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/

void setup() {

  // initialize the manual pushbutton pin as an input:
  pinMode(buttonPin, INPUT);    

  byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
  Wire.begin();

  // Change these values to what you want to set your clock to.
  // You probably only want to set your clock once and then remove
  // the setDateDs1307 call.
  //     second = 45;
  //     minute = 56;
  //     hour = 21;
  //     dayOfWeek = 4;  // Sunday is 0
  //     dayOfMonth = 6;
  //     month = 12;
  //     year = 12;
  //    setDateDs1307(second, minute, hour, dayOfWeek, dayOfMonth, month, year);


  lcd.begin(20, 2); // set up the LCD's number of rows and columns:
  pinMode( BUTTON_ADC_PIN, INPUT );         //ensure A0 is an input
  digitalWrite( BUTTON_ADC_PIN, LOW );      //ensure pullup is off on A0
  //lcd backlight control
  // digitalWrite( LCD_BACKLIGHT_PIN, HIGH );  //backlight control pin D3 is high (on)
  // pinMode( LCD_BACKLIGHT_PIN, OUTPUT );     //D3 is an output
}

/* L O O P |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/
void loop()
{
  byte button;
  byte timestamp;
  microsecond();
  //  lcd.clear();
  if (menulevel1==0) { 
    auto1(); 
  }
  if (backlightcountdown > 0) {
    backlightcountdown--;
    digitalWrite( LCD_BACKLIGHT_PIN, HIGH );
  }
  else {
    digitalWrite( LCD_BACKLIGHT_PIN, LOW );
  }
  //get the latest button pressed, also the buttonJustPressed, buttonJustReleased flags
  button = ReadButtons();
  //blank the demo text line if a new button is pressed or released, ready for a new label to be written
  if( buttonJustPressed || buttonJustReleased )
  {
    lcd.setCursor( 4, 1 );
    lcd.print( "            " );
  }
  switch( button )
  {
  case BUTTON_NONE:
    {
      break;
    }
  case BUTTON_RIGHT:
    {
      backlightcountdown=1000;
      menulevel1=menulevel1++;
      if (menulevel1>3) {
        menulevel1=0;
      }
      lcd.setCursor( 4, 1 );
      lcd.print( "RIGHT" );
      delay(200);
      break;
    }
  case BUTTON_UP:
    {
      backlightcountdown=1000;
      lcd.setCursor( 4, 1 );
      lcd.print( "UP" );
      break;
    }
  case BUTTON_DOWN:
    {
      backlightcountdown=1000;
      lcd.setCursor( 4, 1 );
      lcd.print( "DOWN" );
      break;
    }
  case BUTTON_LEFT:
    {
      backlightcountdown=1000;
      menulevel1=menulevel1-- ;
      if (menulevel1<0) {
        menulevel1=3;
      }

      lcd.setCursor( 4, 1 );
      lcd.print( "LEFT" );
      delay(200);
      break;
    }
  case BUTTON_SELECT:
    {
      backlightcountdown=1000;
      switch(menulevel1) 
      {
      case 0:
        {
          auto1();
          break;
        }
      case 1:
        {
          manual();
          break;
        }
      case 2:
        {
          configure();
          break;
        }
      case 3:
        {
          reset();
          break;
        }
      }
      lcd.setCursor( 4, 1 );
      lcd.print( "SELECT-FLASH" );    

      //      delay( 150 );
      //       LCD_BACKLIGHT_OFF();
      //       delay( 150 );
      //       LCD_BACKLIGHT_ON();   //leave the backlight on at exit
      //       delay( 150 );
      break;
    }
  default:
    {
      break;
    }
  }
  menulevel();
  // print the number of seconds since reset (two digits only)
  timestamp = ( (millis() / 1000) % 100 );   //"% 100" is the remainder of a divide-by-100, which keeps the value as 0-99 even as the result goes over 100
  //       lcd.setCursor( 14, 1 );
  //       if( timestamp <= 9 )
  //          lcd.print( " " );   //quick trick to right-justify this 2 digit value when it's a single digit
  //       lcd.print( timestamp, DEC );

  /*   //debug/test display of the adc reading for the button input voltage pin.
   lcd.setCursor(12, 0);
   lcd.print( "    " );          //quick hack to blank over default left-justification from lcd.print()
   lcd.setCursor(12, 0);         //note the value will be flickering/faint on the LCD
   lcd.print( analogRead( BUTTON_ADC_PIN ) );
   */
  //clear the buttonJustPressed or buttonJustReleased flags, they've already done their job now.
  if( buttonJustPressed )
    buttonJustPressed = false;
  if( buttonJustReleased )
    buttonJustReleased = false;

  ledSetAll();

}
/* R E A D  B U T T O N S |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||*/

byte ReadButtons()
{
  unsigned int buttonVoltage;
  byte button = BUTTON_NONE;   // return no button pressed if the below checks don't write to btn

  //read the button ADC pin voltage
  buttonVoltage = analogRead( BUTTON_ADC_PIN );
  //sense if the voltage falls within valid voltage windows
  if( buttonVoltage < ( RIGHT_10BIT_ADC + BUTTONHYSTERESIS ) )
  {
    button = BUTTON_RIGHT;
  }
  else if(   buttonVoltage >= ( UP_10BIT_ADC - BUTTONHYSTERESIS )
    && buttonVoltage <= ( UP_10BIT_ADC + BUTTONHYSTERESIS ) )
  {
    button = BUTTON_UP;
  }
  else if(   buttonVoltage >= ( DOWN_10BIT_ADC - BUTTONHYSTERESIS )
    && buttonVoltage <= ( DOWN_10BIT_ADC + BUTTONHYSTERESIS ) )
  {
    button = BUTTON_DOWN;
  }
  else if(   buttonVoltage >= ( LEFT_10BIT_ADC - BUTTONHYSTERESIS )
    && buttonVoltage <= ( LEFT_10BIT_ADC + BUTTONHYSTERESIS ) )
  {
    button = BUTTON_LEFT;
  }
  else if(   buttonVoltage >= ( SELECT_10BIT_ADC - BUTTONHYSTERESIS )
    && buttonVoltage <= ( SELECT_10BIT_ADC + BUTTONHYSTERESIS ) )
  {
    button = BUTTON_SELECT;
  }
  //handle button flags for just pressed and just released events
  if( ( buttonWas == BUTTON_NONE ) && ( button != BUTTON_NONE ) )
  {
    //the button was just pressed, set buttonJustPressed, this can optionally be used to trigger a once-off action for a button press eve
    //it's the duty of the receiver to clear these flags if it wants to detect a new button change event
    buttonJustPressed  = true;
    buttonJustReleased = false;
  }
  if( ( buttonWas != BUTTON_NONE ) && ( button == BUTTON_NONE ) )
  {
    buttonJustPressed  = false;
    buttonJustReleased = true;
  }

  //save the latest button value, for change event detection next time round
  buttonWas = button;

  return( button );
}