// 3 Button Toggle by Epic Amplification 
// Radio Buttons!
const int rly1 =  3;    // LED pin number
const int btn1 =  PB0;
const int rly2 =  4;
const int btn2 =  PB1;
const int rly3 =  5;
const int btn3 =  PB2;

char bstate1 = 0;
char bstate2 = 0;
char bstate3 = 0;
unsigned long bcount1 = 0; // button debounce timer.  Replicate as necessary.
unsigned long bcount2 = 0;
unsigned long bcount3 = 0;


// Have we completed the specified interval since last confirmed event?
// "marker" chooses which counter to check
// Routines by Paul__B of Arduino Forum
boolean timeout(unsigned long *marker, unsigned long interval) {
  if (millis() - *marker >= interval) {
    *marker += interval;    // move on ready for next interval
    return true;
  }
  else return false;
}

// Deal with a button read; true if button pressed and debounced is a new event
// Uses reading of button input, debounce store, state store and debounce interval.
// Routines by Paul__B of Arduino Forum
boolean butndown(char button, unsigned long *marker, char *butnstate, unsigned long interval) {
  switch (*butnstate) {               // Odd states if was pressed, >= 2 if debounce in progress
    case 0: // Button up so far,
      if (button == HIGH) return false; // Nothing happening!
      else {
        *butnstate = 2;                 // record that is now pressed
        *marker = millis();             // note when was pressed
        return false;                   // and move on
      }

    case 1: // Button down so far,
      if (button == LOW) return false; // Nothing happening!
      else {
        *butnstate = 3;                 // record that is now released
        *marker = millis();             // note when was released
        return false;                   // and move on
      }

    case 2: // Button was up, now down.
      if (button == HIGH) {
        *butnstate = 0;                 // no, not debounced; revert the state
        return false;                   // False alarm!
      }
      else {
        if (millis() - *marker >= interval) {
          *butnstate = 1;               // jackpot!  update the state
          return true;                  // because we have the desired event!
        }
        else
          return false;                 // not done yet; just move on
      }

    case 3: // Button was down, now up.
      if (button == LOW) {
        *butnstate = 1;                 // no, not debounced; revert the state
        return false;                   // False alarm!
      }
      else {
        if (millis() - *marker >= interval) {
          *butnstate = 0;               // Debounced; update the state
          return false;                 // but it is not the event we want
        }
        else
          return false;                 // not done yet; just move on
      }
    default:                            // Error; recover anyway
      {
        *butnstate = 0;
        return false;                   // Definitely false!
      }
  }
}






void setup()
{
  pinMode(rly1, OUTPUT);
  pinMode(btn1, INPUT_PULLUP);
  pinMode(rly2, OUTPUT);
  pinMode(btn2, INPUT_PULLUP);
  pinMode(rly3, OUTPUT);
  pinMode(btn3, INPUT_PULLUP);
  digitalWrite (rly1, HIGH);
  digitalWrite (rly2, LOW);
  digitalWrite (rly3, LOW);
 
 
}


void loop(){


 
 
  // Select LED if button debounced
  if (butndown(digitalRead(btn3), &bcount3, &bstate3, 2UL )) {
    digitalWrite (rly1, LOW);
    digitalWrite (rly2, LOW);
    digitalWrite (rly3, HIGH);
  }
 
  // Select LED if button debounced
  if (butndown(digitalRead(btn2), &bcount2, &bstate2, 2UL )) {
    digitalWrite (rly1, LOW);
    digitalWrite (rly2, HIGH);
    digitalWrite (rly3, LOW);
  }
   // Select LED if button debounced
  if (butndown(digitalRead(btn1), &bcount1, &bstate1, 2UL )) {
    digitalWrite (rly1, HIGH);
    digitalWrite (rly2, LOW);
    digitalWrite (rly3, LOW);
  }

}