/*
 * This project is a tri digital oscillator using a si5351a break out board.
 * The arduino Uno is used with the LCD Keypad shield unit.
 * 
 * Ideas for this project is for a single or twin or a tri vfo single source for RF measurements.
 * Such measurements are perhaps intermodulation calculations for both RX and TX tests.
 *
 * May perhaps also RX signal I.F. bandwidth measurements and also perhaps AF filtering tests using
 * an RF signal source at the antenna input of the radio.
 * 
 * Code written by Alastair GW0AJU
 * 
 * date :- 8th May 2018
 * updated : 21st May 2019
 * 
 * Note: I have left the "Serial.print" commands within the coding for code fault
 * finding should users experience code faults with the program.
 */

// include the library code:
#include <LiquidCrystal.h>
#include <Wire.h>
#include <EEPROM.h>
#include "si5351.h"
Si5351 si5351;

long sig_gen_freq;

//************ vfo A ************
long start_freq_one;
long carrier_centre_one;
long frequency_one;
int address_vfo_one = 0;
int address_step_one = 6;
long ch_step_one;
long freq_one;
long VFO_freq_set_one;
float freq_math_one;

//************* vfo B ***********
long start_freq_two;
long carrier_centre_two;
long frequency_two;
int address_vfo_two = 10;
int address_step_two = 16;
long ch_step_two;
long freq_two;
long VFO_freq_set_two;
float freq_math_two;

// ******* vfo C *************
long start_freq_three;
long carrier_centre_three;
long frequency_three;
int address_vfo_three = 20;
int address_step_three = 26;
long ch_step_three;
long freq_three;
long VFO_freq_set_three;
float freq_math_three;

// *****  analog port zero sample values for button selection *******
int right_button_low = 0;
int right_button_high = 50;

int up_button_low = 70;
int up_button_high = 170;

int down_button_low = 200;
int down_button_high = 300;

int left_button_low = 350;
int left_button_high = 450;

int select_button_low = 600;
int select_button_high = 700;
//*******************************************************************


int address_step = 30;

int bc_one;
int bc_two;
int bc_three;

int bc_vfo;

int key_delay = 250;

// max limits of the si5351a digitql oscillator
long f_max = 160e6;
long f_min = 8e3;
 
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);


//This function will write a 4 byte (32bit) long to the eeprom at
//the specified address to address + 3.
void EEPROMWritelong(int address, long value)
       {
       //Decomposition from a long to 4 bytes by using bitshift.
       //One = Most significant -> Four = Least significant byte
       byte four = (value & 0xFF);
       byte three = ((value >> 8) & 0xFF);
       byte two = ((value >> 16) & 0xFF);
       byte one = ((value >> 24) & 0xFF);

       //Write the 4 bytes into the eeprom memory.
       EEPROM.write(address, four);
       EEPROM.write(address + 1, three);
       EEPROM.write(address + 2, two);
       EEPROM.write(address + 3, one);
       }

//This function will return a 4 byte (32bit) long from the eeprom
//at the specified address to address + 3.
long EEPROMReadlong(long address)
       {
       //Read the 4 bytes from the eeprom memory.
       long four = EEPROM.read(address);
       long three = EEPROM.read(address + 1);
       long two = EEPROM.read(address + 2);
       long one = EEPROM.read(address + 3);

       //Return the recomposed long by using bitshift.
       return ((four << 0) & 0xFF) + ((three << 8) & 0xFFFF) + ((two << 16) & 0xFFFFFF) + ((one << 24) & 0xFFFFFFFF);
       }
 


void setup()
{
  si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0, 0);
  si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLA);
  si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLB);
  si5351.drive_strength(SI5351_CLK0, SI5351_DRIVE_2MA);
  si5351.drive_strength(SI5351_CLK1, SI5351_DRIVE_2MA);
  si5351.drive_strength(SI5351_CLK2, SI5351_DRIVE_2MA);
  si5351.output_enable(SI5351_CLK0, 1);
  si5351.output_enable(SI5351_CLK1, 1);
  si5351.output_enable(SI5351_CLK2, 1);
  // calibration of vfo with digital frequency counter to test 25MHz crystal
  //si5351.set_freq(50000000,  SI5351_CLK2); 
  si5351.update_status();

  Serial.begin(9600);
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.setCursor(0,0);
  lcd.print("Sig Gen Shield");
  lcd.setCursor(0,1);
  lcd.print("Alastair GW0AJU");
  delay(2000);
  
    Serial.println("reset start");
      
       //Starting at the first byte on the eeprom.
       start_freq_one = EEPROMReadlong(address_vfo_one);
       if  (start_freq_one >  f_min && start_freq_one < f_max)
       {
        carrier_centre_one = start_freq_one;
        bc_one = EEPROM.read(address_step_one);
       }
       else
       {
         start_freq_one = 3.710e6;
         EEPROMWritelong(address_vfo_one, start_freq_one);
         carrier_centre_one = EEPROMReadlong(address_vfo_one);
         bc_one = 5;
         EEPROM.write(address_step_one, bc_one);
         bc_one = EEPROM.read(address_step_one);
         bc_vfo = 1;
         EEPROM.write(address_step, bc_vfo);
         bc_vfo = 1;
         bc_one = 4;
       }

       //Starting at the first byte on the eeprom.
       start_freq_two = EEPROMReadlong(address_vfo_two);
       if  (start_freq_two >  f_min && start_freq_two < f_max)
       {
        carrier_centre_two = start_freq_two;
        bc_two = EEPROM.read(address_step_two);
       }
       else
       {
         start_freq_two = 7.120e6;
         EEPROMWritelong(address_vfo_two, start_freq_two);
         carrier_centre_two = EEPROMReadlong(address_vfo_two);
         bc_two = 4;  
         EEPROM.write(address_step_two, bc_two);
         bc_two = EEPROM.read(address_step_two);
         bc_vfo = 1;
         bc_one = 4;
       }

       //Starting at the first byte on the eeprom.
       start_freq_three = EEPROMReadlong(address_vfo_three);
       if  (start_freq_three > f_min && start_freq_three < f_max)
       {
        carrier_centre_three = start_freq_three;
        bc_three = EEPROM.read(address_step_three);
       }
       else
       {
         start_freq_three = 14.25e6;
         EEPROMWritelong(address_vfo_three, start_freq_three);
         carrier_centre_three = EEPROMReadlong(address_vfo_three);
         bc_three = 3; 
         EEPROM.write(address_step_three, bc_three);
         bc_three = EEPROM.read(address_step_three);
         bc_vfo = 1;
         bc_one = 4;
       }

   bc_vfo = EEPROM.read(address_step);
   selected_vfo();  // selection of vfo step

   Serial.println("reset start end");

}

void loop()
{
  vfo_selection();
  delay(300);
}


void vfo_selection()
{  
  Serial.println("vfo_selection");
  int xy;
  xy = analogRead (0);
  if (xy > 600 && xy < 660)
   {
    //lcd.print ("Select");
    bc_vfo = bc_vfo + 1;
                if (bc_vfo == 5)  // to detect if the bottom of band, them set to top range for down count
                   {
                        bc_vfo = 1; // reach bottom now starting from the top downwards
                   }
                   Serial.println("");
                   Serial.print("bc_vfo = ");
                   Serial.print(bc_vfo);
                   Serial.println("");
                   Serial.println("");
                   EEPROM.write(address_step, bc_vfo);
                   selected_vfo();  // selection of vfo step
   }
  
}


void selected_vfo()
{
  Serial.println("selected_vfo");
               if (bc_vfo == 1 )
                  {
                    lcd.home();
                    lcd.clear();
                    lcd.setCursor(0,0);
                    lcd.print("Oscillator o/p's"); 
                    lcd.setCursor(0,1);
                    lcd.print("disabled");
                    si5351.output_enable(SI5351_CLK0, 0);
                    si5351.output_enable(SI5351_CLK1, 0);
                    si5351.output_enable(SI5351_CLK2, 0);                  
                  }  
              else if (bc_vfo == 2 )
                  {
                    lcd.home();
                    lcd.clear();
                    lcd.setCursor(0,0);
                    lcd.print("A");
                    lcd.setCursor(13,0);
                    lcd.print("KHz"); 
                    lcd.setCursor(0,1);
                    lcd.print("inc/dec = ");
                    si5351.output_enable(SI5351_CLK0, 1);
                    si5351.output_enable(SI5351_CLK1, 1);
                    si5351.output_enable(SI5351_CLK2, 1);
                    carrier_centre_one = EEPROMReadlong(address_vfo_one); 
                    vfo_tune_one();
                    bc_one = EEPROM.read(address_step_one);
                    selection_step_one();                               
                    keyboard_access_vfo_one();
                  } 
              else if (bc_vfo == 3 )
                  {
                    lcd.home();
                    lcd.clear();
                    lcd.setCursor(0,0);
                    lcd.print("B");
                    lcd.setCursor(13,0);
                    lcd.print("KHz"); 
                    lcd.setCursor(0,1);
                    lcd.print("inc/dec = ");
                    si5351.output_enable(SI5351_CLK0, 1);
                    si5351.output_enable(SI5351_CLK1, 1);
                    si5351.output_enable(SI5351_CLK2, 1);
                    carrier_centre_two = EEPROMReadlong(address_vfo_two); 
                    vfo_tune_two();
                    bc_two = EEPROM.read(address_step_two); 
                    selection_step_two();
                    keyboard_access_vfo_two();                    
                  }
              else  if (bc_vfo == 4 )
                  {
                    lcd.home();
                    lcd.clear();
                    lcd.setCursor(0,0);
                    lcd.print("C");
                    lcd.setCursor(13,0);
                    lcd.print("KHz"); 
                    lcd.setCursor(0,1);
                    lcd.print("inc/dec = ");
                    si5351.output_enable(SI5351_CLK0, 1);
                    si5351.output_enable(SI5351_CLK1, 1);
                    si5351.output_enable(SI5351_CLK2, 1);
                    carrier_centre_three = EEPROMReadlong(address_vfo_three); 
                    vfo_tune_three();
                    bc_three = EEPROM.read(address_step_three);
                    selection_step_three(); 
                    keyboard_access_vfo_three();                   
                  }  
                 
}

void keyboard_access_vfo_one()
{
  top_one:
  delay(key_delay);
  Serial.println("keyboard_access_vfo_one");
  int x_one;
  x_one = analogRead (0);
  lcd.setCursor(10,1);
  if (x_one < right_button_high) 
  {
    Serial.print ("Right ");
                bc_one = bc_one + 1;
                if (bc_one == 10)  // to detect if the bottom of band, them set to top range for down count
                   {
                        bc_one = 1; // reach bottom now starting from the top downwards
                   }
                   EEPROM.write(address_step_one, bc_one);
                   selection_step_one();  // selection of vfo step
               
  }
  else if (x_one > up_button_low  && x_one < up_button_high )
  {
   Serial.print ("Up    ");
     
                       // up band movement
                       carrier_centre_one = carrier_centre_one + (1 * ch_step_one);  // ch_step increments
                       if ( carrier_centre_one >= f_max )
                       {
                        carrier_centre_one = f_max;
                       }
                       EEPROMWritelong(address_vfo_one, carrier_centre_one); 
                       vfo_tune_one();                                     
  }
  else if (x_one > down_button_low  && x_one < down_button_high )
  {
    Serial.print ("Down  ");
                       // down band movement
                       carrier_centre_one = carrier_centre_one - (1 * ch_step_one);  // ch_step increments
                       if ( carrier_centre_one <= f_min )
                       {
                        carrier_centre_one = f_min;
                       }
                       EEPROMWritelong(address_vfo_one, carrier_centre_one); 
                       vfo_tune_one();
  }
  else if (x_one > left_button_low && x_one < left_button_high )
  {
   Serial.print ("Left  ");
                 bc_one = bc_one - 1;
                 if (bc_one == 0)  // to detect if the bottom of band, them set to top range for down count
                   {
                     bc_one = 9; // reach bottom now starting from the top downwards
                   }
                   EEPROM.write(address_step_one, bc_one);
                   selection_step_one();  // selection of vfo step
                  
  }
 
 else if (x_one > select_button_low && x_one <select_button_high )
   {
     Serial.print ("jump out of keyboard one");
   vfo_selection();
   
   }
    goto top_one;
}



void vfo_tune_one()
{ 
  Serial.println("vfo_tune_one");
            frequency_one = carrier_centre_one;
            VFO_freq_set_one = frequency_one * 100ULL;
            si5351.set_freq(VFO_freq_set_one, SI5351_CLK0);
            si5351.update_status();
            lcd.setCursor(2,0);
            lcd.print("           ");
            lcd.setCursor(2,0);
            freq_math_one = frequency_one/1e3;
            lcd.print(freq_math_one,3);
}

void selection_step_one()   // to change the hf band of operation
{ Serial.println("selection_step_one");
              if (bc_one == 1 )
                  {
                    ch_step_one = 5e6;  // 5KHz vfo increment
                    lcd.setCursor(10,1);
                    lcd.print("       ");
                    lcd.setCursor(10,1);
                    lcd.print("5MHz");
                    EEPROM.write(address_step_one, bc_one);
                    
                  } 
            if (bc_one == 2 )
                  {
                    ch_step_one = 1e6;  // 5KHz vfo increment
                    lcd.setCursor(10,1);
                    lcd.print("       ");
                    lcd.setCursor(10,1);
                    lcd.print("1MHz");
                    EEPROM.write(address_step_one, bc_one);
                    
                  } 
               if (bc_one == 3 )
                  {
                   ch_step_one = 100e3;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("100KHz");
                   EEPROM.write(address_step_one, bc_one); 
                    
                  } 
                if (bc_one == 4 )
                  {
                   ch_step_one = 10e3;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("10KHz"); 
                   EEPROM.write(address_step_one, bc_one);
                    
                  } 
                  if (bc_one == 5 )
                  {
                   ch_step_one = 1e3;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("1KHz"); 
                   EEPROM.write(address_step_one, bc_one);
                  
                  } 
                   if (bc_one == 6 )
                  {
                   ch_step_one = 500;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("500Hz"); 
                   EEPROM.write(address_step_one, bc_one);
                    
                  } 
                  if (bc_one == 7 )
                  {
                   ch_step_one = 100;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("100Hz"); 
                   EEPROM.write(address_step_one, bc_one); 
                    
                  } 
                   if (bc_one == 8 )
                  {
                   ch_step_one = 10;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("10Hz"); 
                   EEPROM.write(address_step_one, bc_one); 
                     
                  } 
                   if (bc_one == 9 )
                  {
                   ch_step_one = 1;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("1Hz"); 
                   EEPROM.write(address_step_one, bc_one); 
                     
                  } 
}


void keyboard_access_vfo_two()
{
  top_two:
  delay(key_delay);
  Serial.println("keyboard_access_vfo_two");
  int x_two;
  x_two = analogRead (0);
  lcd.setCursor(10,1);
  if (x_two < right_button_high) 
  {
    //lcd.print ("Right ");
                bc_two = bc_two + 1;
                if (bc_two == 10)  // to detect if the bottom of band, them set to top range for down count
                   {
                        bc_two = 1; // reach bottom now starting from the top downwards
                   }
                   EEPROM.write(address_step_two, bc_two);
                   selection_step_two();  // selection of vfo step
                 
  }
  else if (x_two > up_button_low && x_two < up_button_high)
  {
   // lcd.print ("Up    ");
     
                       // up band movement
                       carrier_centre_two = carrier_centre_two + (1 * ch_step_two);  // ch_step increments
                       if ( carrier_centre_two >= f_max )
                       {
                        carrier_centre_two = f_max;
                       }
                       EEPROMWritelong(address_vfo_two, carrier_centre_two); 
                       vfo_tune_two();
                                                             
  }
  else if (x_two > down_button_low && x_two < down_button_high)
  {
    //lcd.print ("Down  ");
                       // down band movement
                       carrier_centre_two = carrier_centre_two - (1 * ch_step_two);  // ch_step increments
                       if ( carrier_centre_two <= f_min )
                       {
                        carrier_centre_two = f_min;
                       }
                       EEPROMWritelong(address_vfo_two, carrier_centre_two); 
                       vfo_tune_two();
                      
  }
  else if (x_two > left_button_low && x_two < left_button_high)
  {
   // lcd.print ("Left  ");
                 bc_two = bc_two - 1;
                 if (bc_two == 0)  // to detect if the bottom of band, them set to top range for down count
                   {
                     bc_two = 9; // reach bottom now starting from the top downwards
                   }
                   EEPROM.write(address_step_two, bc_two);
                   selection_step_two();  // selection of vfo step
                 
  }
  
else if (x_two > select_button_low && x_two < select_button_high)
   {
   vfo_selection();
   
   }
    goto top_two;
}



void vfo_tune_two()
{ Serial.println(" vfo_tune_two");
            frequency_two = carrier_centre_two;
            VFO_freq_set_two = frequency_two * 100ULL;
            si5351.set_freq(VFO_freq_set_two, SI5351_CLK1);
            si5351.update_status();
            lcd.setCursor(2,0);
            lcd.print("           ");
            lcd.setCursor(2,0);
            freq_math_two = frequency_two/1e3;
            lcd.print(freq_math_two,3);
}

void selection_step_two()   // to change the hf band of operation
{ Serial.println("selection_step_two");
              if (bc_two == 1 )
                  {
                    ch_step_two = 5e6;  // 5KHz vfo increment
                    lcd.setCursor(10,1);
                    lcd.print("       ");
                    lcd.setCursor(10,1);
                    lcd.print("5MHz");
                    EEPROM.write(address_step_two, bc_two);
                  } 
            if (bc_two == 2 )
                  {
                    ch_step_two = 1e6;  // 5KHz vfo increment
                    lcd.setCursor(10,1);
                    lcd.print("       ");
                    lcd.setCursor(10,1);
                    lcd.print("1MHz");
                    EEPROM.write(address_step_two, bc_two);
                  } 
               if (bc_two == 3 )
                  {
                   ch_step_two = 100e3;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("100KHz");
                   EEPROM.write(address_step_two, bc_two);   
                  } 
                if (bc_two == 4 )
                  {
                   ch_step_two = 10e3;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("10KHz"); 
                   EEPROM.write(address_step_two, bc_two);     
                  } 
                  if (bc_two == 5 )
                  {
                   ch_step_two = 1e3;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("1KHz"); 
                   EEPROM.write(address_step_two, bc_two);     
                  } 
                   if (bc_two == 6 )
                  {
                   ch_step_two = 500;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("500Hz"); 
                   EEPROM.write(address_step_two, bc_two);     
                  } 
                  if (bc_two == 7 )
                  {
                   ch_step_two = 100;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("100Hz"); 
                   EEPROM.write(address_step_two, bc_two);     
                  } 
                   if (bc_two == 8 )
                  {
                   ch_step_two = 10;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("10Hz"); 
                   EEPROM.write(address_step_two, bc_two);     
                  } 
                    if (bc_two == 9 )
                  {
                   ch_step_two = 1;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("1Hz"); 
                   EEPROM.write(address_step_two, bc_two);     
                  } 
}



void keyboard_access_vfo_three()
{
  
  top_three:
  delay(key_delay);
  Serial.println("keyboard_access_vfo_three");
  int x_three;
  x_three = analogRead (0);
  lcd.setCursor(10,1);
  if (x_three < right_button_high ) 
  {
    //lcd.print ("Right ");
                bc_three = bc_three + 1;
                if (bc_three == 10)  // to detect if the bottom of band, them set to top range for down count
                   {
                        bc_three = 1; // reach bottom now starting from the top downwards
                   }
                   EEPROM.write(address_step_three, bc_three);
                   selection_step_three();  // selection of vfo step
                 
  }
  else if (x_three > up_button_low && x_three < up_button_high)
  {
   // lcd.print ("Up    ");
     
                       // up band movement
                       carrier_centre_three = carrier_centre_three + (1 * ch_step_three);  // ch_step increments
                       if ( carrier_centre_three >= f_max )
                       {
                        carrier_centre_three = f_max;
                       }
                       EEPROMWritelong(address_vfo_three, carrier_centre_three); 
                       vfo_tune_three();
                                                             
  }
  else if (x_three > down_button_low && x_three < down_button_high)
  {
    //lcd.print ("Down  ");
                       // down band movement
                       carrier_centre_three = carrier_centre_three - (1 * ch_step_three);  // ch_step increments
                       if ( carrier_centre_three <= f_min )
                       {
                        carrier_centre_three = f_min;
                       }
                       EEPROMWritelong(address_vfo_three, carrier_centre_three); 
                       vfo_tune_three();
                       
  }
  else if (x_three > left_button_low && x_three < left_button_high)
  {
   // lcd.print ("Left  ");
                 bc_three = bc_three - 1;
                 if (bc_three == 0)  // to detect if the bottom of band, them set to top range for down count
                   {
                     bc_three = 9; // reach bottom now starting from the top downwards
                   }
                   EEPROM.write(address_step_three, bc_three);
                   selection_step_three();  // selection of vfo step
                    
  }
  
else if (x_three > select_button_low && x_three < select_button_high)
   {
   vfo_selection();
   
   }

    goto top_three;

}



void vfo_tune_three()
{ Serial.println("vfo_tune_three");
            frequency_three = carrier_centre_three;
            VFO_freq_set_three = frequency_three * 100ULL;
            si5351.set_freq(VFO_freq_set_three, SI5351_CLK2);
            si5351.update_status();
            lcd.setCursor(2,0);
            lcd.print("           ");
            lcd.setCursor(2,0);
            freq_math_three = frequency_three/1e3;
            lcd.print(freq_math_three,3);
}

void selection_step_three()   // to change the hf band of operation
{ Serial.println("selection_step_three");
              if (bc_three == 1 )
                  {
                    ch_step_three = 5e6;  // 5KHz vfo increment
                    lcd.setCursor(10,1);
                    lcd.print("       ");
                    lcd.setCursor(10,1);
                    lcd.print("5MHz");
                    EEPROM.write(address_step_three, bc_three);
                  } 
            if (bc_three == 2 )
                  {
                    ch_step_three = 1e6;  // 5KHz vfo increment
                    lcd.setCursor(10,1);
                    lcd.print("       ");
                    lcd.setCursor(10,1);
                    lcd.print("1MHz");
                    EEPROM.write(address_step_three, bc_three);
                  } 
               if (bc_three == 3 )
                  {
                   ch_step_three = 100e3;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("100KHz");
                   EEPROM.write(address_step_three, bc_three);   
                  } 
                if (bc_three == 4 )
                  {
                   ch_step_three = 10e3;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("10KHz"); 
                   EEPROM.write(address_step_three, bc_three);     
                  } 
                  if (bc_three == 5 )
                  {
                   ch_step_three = 1e3;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("1KHz"); 
                   EEPROM.write(address_step_three, bc_three);     
                  } 
                   if (bc_three == 6 )
                  {
                   ch_step_three = 500;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("500Hz"); 
                   EEPROM.write(address_step_three, bc_three);     
                  } 
                  if (bc_three == 7 )
                  {
                   ch_step_three = 100;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("100Hz"); 
                   EEPROM.write(address_step_three, bc_three);     
                  } 
                   if (bc_three == 8 )
                  {
                   ch_step_three = 10;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("10Hz"); 
                   EEPROM.write(address_step_three, bc_three);     
                  } 
                    if (bc_three == 9 )
                  {
                   ch_step_three = 1;
                   lcd.setCursor(10,1);
                   lcd.print("       ");
                   lcd.setCursor(10,1);
                   lcd.print("1Hz"); 
                   EEPROM.write(address_step_three, bc_three);     
                  } 
}