/*
  This entire program is taken from Jason Mildrum, NT7S and Przemek Sadowski, SQ9NJE.
  There is not enough original code written by me to make it worth mentioning.
  http://nt7s.com/
  http://sq9nje.pl/
  http://ak2b.blogspot.com/
  */
  
  #include <Rotary.h>
  #include <si5351.h>
  #include <Wire.h>
  #include <LiquidCrystal.h>
  
  
  #define F_MIN        6900000L               // Lower frequency limit
  #define F_MAX        7400000L 


  #define ENCODER_A    3                      // Encoder pin A
  #define ENCODER_B    2                      // Encoder pin B
  #define ENCODER_BTN  11  
  #define LCD_RS		5
  #define LCD_E		        6
  #define LCD_D4		7
  #define LCD_D5		8
  #define LCD_D6		9
  #define LCD_D7		10
  
  LiquidCrystal lcd(LCD_RS, LCD_E, LCD_D4, LCD_D5, LCD_D6, LCD_D7);       // LCD - pin assignement in 
  Si5351 si5351;
  Rotary r = Rotary(ENCODER_A, ENCODER_B);
  
  volatile uint32_t vfo = 4000000L; //start freq - change to suit
  volatile uint32_t LSB = 4970000L;  //change these to suit your needs
  volatile uint32_t USB = 5000500L;
  volatile uint32_t bfo = 11970000L;	 //start bfo freq
  volatile uint32_t radix = 1000;	//start step size
  boolean changed_f = 0;
  String tbfo = "LSB";
  /***/
  /* Interrupt service routine for      */
  /* encoder frequency change           */
  /***/
  ISR(PCINT2_vect) {
    unsigned char result = r.process();
    if (result == DIR_CW)
      set_frequency(1);
    else if (result == DIR_CCW) 
      set_frequency(-1);
      //display_frequency();
  }
  /***/
  /* Change the frequency               */
  /* dir = 1    Increment               */
  /* dir = -1   Decrement               */
  /***/
  void set_frequency(short dir)
  {
    if(dir == 1)
      vfo += radix;
    if(dir == -1)
      vfo -= radix;
      
      display_frequency();
   
    if(vfo > F_MAX)
      vfo = F_MAX;
    if(vfo < F_MIN)
      vfo = F_MIN;

    //display_frequency();
    changed_f = 1;  
  }
  /***/
  /* Read the button with debouncing    */
  /***/
  boolean get_button()
  {
    if(!digitalRead(ENCODER_BTN))
    {
      delay(20);
      if(!digitalRead(ENCODER_BTN))
      {
        while(!digitalRead(ENCODER_BTN));
        return 1;
      }
    }
    return 0;
  }
  
  /***/
  /* Displays the frequency             */
  /***/
    void display_frequency()
  {
    uint16_t f, g;
    
    lcd.setCursor(4, 0);
    f = vfo / 1000000; 	//variable is now vfo instead of 'frequency'
    if(f<10)
      lcd.print(' ');
    lcd.print(f);
    lcd.print('.');
    f = (vfo % 1000000)/1000;
    if(f<100)
      lcd.print('0');
    if(f<10)
      lcd.print('0');
    lcd.print(f);
    lcd.print('.');
    f = vfo % 1000;
    if(f<100)
      lcd.print('0');
    if(f<10)
      lcd.print('0');
    lcd.print(f);
    lcd.print("Hz");
    lcd.setCursor(0, 1);
    lcd.print(tbfo);
    //Serial.println(vfo + bfo);
    //Serial.println(tbfo);
    
  }
  
  /***/
  /* Displays the frequency change step */
  /***/
  void display_radix()
  {
    lcd.setCursor(10, 1);
    switch(radix)
    {
      case 10:
        lcd.print("  10");
        break;
      case 100:
        lcd.print(" 100");
        break;
      case 1000:
        lcd.print("  1k");
        break;
      case 10000:
        lcd.print(" 10k");
        break;
      case 100000:
        lcd.print("100k");
        break;
    }
    lcd.print("Hz");
  }

  
  void setup()
  {
  	Serial.begin(19200);
    lcd.begin(16, 2);                                                    // Initialize and clear the LCD
    lcd.clear();
    Wire.begin();
    // Start serial and initialize the Si5351
    si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0, 0);
    
    // Set CLK0 to output 14 MHz with a fixed PLL frequency 
    si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLA);
    si5351.set_freq(vfo, SI5351_CLK0);
    // Set CLK1 to output 20 MHz  
    //si5351.set_freq(frequency1, 0, SI5351_CLK1);
    // Set CLK2 to output 15 MHz
    si5351.set_freq( bfo, SI5351_CLK2);
    si5351.drive_strength(SI5351_CLK0,SI5351_DRIVE_8MA);
    //si5351.drive_strength(SI5351_CLK1,SI5351_DRIVE_2MA);
    //si5351.drive_strength(SI5351_CLK2,SI5351_DRIVE_6MA);
    
     pinMode(ENCODER_BTN, INPUT_PULLUP);
     PCICR |= (1 << PCIE2);           // Enable pin change interrupt for the encoder
     PCMSK2 |= (1 << PCINT18) | (1 << PCINT19);
     sei();  
     display_frequency();  // Update the display
     display_radix();
  }
  
  
  void loop()
  {
    // Update the display if the frequency has been changed
    if(changed_f)
    {
      display_frequency();
      
      si5351.set_freq(vfo + bfo, SI5351_CLK0);
    if(vfo >= 10000000L & tbfo != "USB")
    {
      bfo = USB;
      tbfo = "USB";
     // si5351.set_freq( bfo, SI5351_CLK2);
      Serial.println("We've switched from LSB to USB");
    }
    else if(vfo < 10000000L & tbfo != "LSB")
    {
      bfo = LSB;
      tbfo = "LSB";
    //  si5351.set_freq( bfo, SI5351_CLK2);
      Serial.println("We've switched from USB to LSB");
    }
      changed_f = 0;
    }
    
    // Button press changes the frequency change step
    if(get_button())
    {
      switch(radix)
      {
        case 10:
          radix = 100;
          break;
        case 100:
          radix = 1000;
          break;
        case 1000:
          radix = 10000;
          break;
          case 10000:
          radix = 100000;
          break;
        case 100000:
          radix = 10;
          break;
      }
      display_radix();
    }   
  }