Morse "bug" keyer

//Morse "bug" keyer

//buttons
#define button_1 2
#define button_2 3

//speed selector pins
//take one to ground to select speed 
//default is 5 words per minute
#define selector_1 A0
#define selector_2 A1
#define selector_3 A2

//the buzzer
const int sounder_pin=5;// the pin we attach our sounder to
const int duty_cycle=128;//50% duty cycle for analogWrite()


//required to debounce switches
#define MAX_CHECKS 10
volatile uint8_t Debounced_State=0;//accessed by isr and main loop code
uint8_t State[MAX_CHECKS]={0};
uint8_t Index=0;


void setup() {
  // put your setup code here, to run once:
  
          pinMode(button_1,INPUT_PULLUP);
          pinMode(button_2,INPUT_PULLUP);
          
          pinMode(selector_1,INPUT_PULLUP);
          pinMode(selector_2,INPUT_PULLUP);
          pinMode(selector_3,INPUT_PULLUP);
          
          pinMode(sounder_pin, OUTPUT);

              // initialize timer1 
  noInterrupts();           // disable all interrupts
  TCCR1A = 0;
  TCCR1B = 0;
  TCNT1  = 0;

  OCR1A = 625;              // compare match register  16MHX/256/100HZ 
  TCCR1B |= (1 << WGM12);   // CTC mode
  TCCR1B |= (1 << CS12);    // 256 prescaler 
  TIMSK1 |= (1 << OCIE1A);  // enable timer compare interrupt
  interrupts();             // enable all interrupts
  
}

void loop() {
  // put your main code here, to run repeatedly:

static int transferred_value=0;
static bool do_character=false;
static bool do_dot=false;
static bool wait_up=false;

    noInterrupts();           // disable all interrupts 
    transferred_value=Debounced_State;      
    interrupts();             // enable all interrupts

    
if (!transferred_value){wait_up=false;}//if all buttons released
if (transferred_value){
                      
                      if(transferred_value==2){do_dot=true;do_character=true;wait_up=true;}//dot                                           
                      if(transferred_value==1){if(!wait_up){do_dot=false;do_character=true;wait_up=true;}}//dash
                      
                    }   


//morse speed
//all timing is based around the length of the dot
//source for timing -> http://www.kent-engineers.com/codespeed.htm

static unsigned long unit_length=240;//default 5 words per minute
if(!digitalRead(A0)){unit_length=240;}//dot time calculated for 5 words per minute
if(!digitalRead(A1)){unit_length=92;}//dot time calculated for 13 words per minute
if(!digitalRead(A2)){unit_length=60;}//dot time calculated for 20 words per minute
  

const unsigned long dot=unit_length;
const unsigned long dash=unit_length*3;
const unsigned long intra_letter_space=unit_length;//space between dot's and dashes within letter


if (do_character) 
{
  do_character=false;


              if (!do_dot){ //dash
                        analogWrite(sounder_pin, duty_cycle); 
                        delay(dash);                       // wait for a while
                        analogWrite(sounder_pin,0);
                        delay(intra_letter_space);         // space between letter parts
                         }
                      else{ //dot
                            analogWrite(sounder_pin, duty_cycle);
                            delay(dot);                    // wait for a while
                            analogWrite(sounder_pin,0);
                            delay(intra_letter_space);     // space between letter parts
                            }

}


}
/*-----------------*/
//my_functions
ISR(TIMER1_COMPA_vect)          // timer compare interrupt service routine
{
//code source - A Guide to Debouncing by Jack G. Ganssle 
//read buttons
  uint8_t temp=0x00;
  
  temp|=!digitalRead(button_1)<<1;
  temp|=!digitalRead(button_2)<<0;
            
//debounce   
  uint8_t i,j;

  State[Index]= temp;
  ++Index;
  j=0xFF;
  for (i=0;i<MAX_CHECKS;i++){j=j&State[i];}
  Debounced_State=j;
  if(Index>=MAX_CHECKS){Index=0;} 

}
//-----------end------------