//
//
// hello.ftdi.44.echo.c
//
// 115200 baud FTDI character echo, with flash string
//
// set lfuse to 0x7E for 20 MHz xtal
//
// Neil Gershenfeld
// 10/16/10
//
// (c) Massachusetts Institute of Technology 2010
// Permission granted for experimental and personal use;
// license for commercial sale available from MIT.
//

#include <avr/io.h>
#include <util/delay.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>

#define output(directions,pin) (directions |= pin) // set port direction for output
#define set(port,pin) (port |= pin) // set port pin
#define clear(port,pin) (port &= (~pin)) // clear port pin
#define pin_test(pins,pin) (pins & pin) // test for port pin
#define bit_test(byte,bit) (byte & (1 << bit)) // test for bit set
#define bit_delay_time 8.5 // bit delay for 115200 with overhead
#define bit_delay() _delay_us(bit_delay_time) // RS232 bit delay
#define half_bit_delay() _delay_us(bit_delay_time/2) // RS232 half bit delay
#define char_delay() _delay_ms(10) // char 

#define serial_port PORTA
#define serial_direction DDRA
#define serial_pins PINA
#define serial_pin_in (1 << PA0)
#define serial_pin_out (1 << PA1)
#define led_pin (1 << PA7)
#define serial_interrupt (1 << PCIE0)
#define serial_interrupt_pin (1 << PCINT0)

#define button_port PORTB
#define button_direction DDRB
#define button_pin (1 << PB2)

void get_char(volatile unsigned char *pins, unsigned char pin, char *rxbyte) {
   //
   // read character into rxbyte on pins pin
   //    assumes line driver (inverts bits)
   //
   *rxbyte = 0;
   while (pin_test(*pins,pin))
      //
      // wait for start bit
      //
      ;
   //
   // delay to middle of first data bit
   //
   half_bit_delay();
   bit_delay();
   //
   // unrolled loop to read data bits
   //
   if pin_test(*pins,pin)
      *rxbyte |= (1 << 0);
   else
      *rxbyte |= (0 << 0);
   bit_delay();
   if pin_test(*pins,pin)
      *rxbyte |= (1 << 1);
   else
      *rxbyte |= (0 << 1);
   bit_delay();
   if pin_test(*pins,pin)
      *rxbyte |= (1 << 2);
   else
      *rxbyte |= (0 << 2);
   bit_delay();
   if pin_test(*pins,pin)
      *rxbyte |= (1 << 3);
   else
      *rxbyte |= (0 << 3);
   bit_delay();
   if pin_test(*pins,pin)
      *rxbyte |= (1 << 4);
   else
      *rxbyte |= (0 << 4);
   bit_delay();
   if pin_test(*pins,pin)
      *rxbyte |= (1 << 5);
   else
      *rxbyte |= (0 << 5);
   bit_delay();
   if pin_test(*pins,pin)
      *rxbyte |= (1 << 6);
   else
      *rxbyte |= (0 << 6);
   bit_delay();
   if pin_test(*pins,pin)
      *rxbyte |= (1 << 7);
   else
      *rxbyte |= (0 << 7);
   //
   // wait for stop bit
   //
   bit_delay();
   half_bit_delay();
   }

void put_char(volatile unsigned char *port, unsigned char pin, char txchar) {
   //
   // send character in txchar on port pin
   //    assumes line driver (inverts bits)
   //
   // start bit
   //
   clear(*port,pin);
   bit_delay();
   //
   // unrolled loop to write data bits
   //
   if bit_test(txchar,0)
      set(*port,pin);
   else
      clear(*port,pin);
   bit_delay();
   if bit_test(txchar,1)
      set(*port,pin);
   else
      clear(*port,pin);
   bit_delay();
   if bit_test(txchar,2)
      set(*port,pin);
   else
      clear(*port,pin);
   bit_delay();
   if bit_test(txchar,3)
      set(*port,pin);
   else
      clear(*port,pin);
   bit_delay();
   if bit_test(txchar,4)
      set(*port,pin);
   else
      clear(*port,pin);
   bit_delay();
   if bit_test(txchar,5)
      set(*port,pin);
   else
      clear(*port,pin);
   bit_delay();
   if bit_test(txchar,6)
      set(*port,pin);
   else
      clear(*port,pin);
   bit_delay();
   if bit_test(txchar,7)
      set(*port,pin);
   else
      clear(*port,pin);
   bit_delay();
   //
   // stop bit
   //
   set(*port,pin);
   bit_delay();
   }

void put_string(volatile unsigned char *port, unsigned char pin, PGM_P str) {
   //
   // send character in txchar on port pin
   //    assumes line driver (inverts bits)
   //
   static char chr;
   static int index;
   index = 0;
   do {
      chr = pgm_read_byte(&(str[index]));
      put_char(&serial_port, serial_pin_out, chr);
      ++index;
      } while (chr != 0);
   }

void turnLedOn(){
	clear(serial_port,led_pin);
}

void turnLedOff(){
	set(serial_port,led_pin);
}

void longPause(){
	_delay_ms(1000);
}

void shortPause(){
	_delay_ms(300);
}

void dot(){
	turnLedOn();
	shortPause();
	turnLedOff();
	shortPause();
}

void dash(){
	turnLedOn();
	longPause();
	turnLedOff();
	shortPause();
}


void morseIt(char Mchar){
	if(Mchar == 'a'){
		longPause();
		dot();
		dash();
		longPause();
	}
	else if(Mchar == 'b'){
		longPause();
		dash();
		dot();
		dot();
		dot();
		longPause();		
	}
	else if(Mchar == 'c'){
		longPause();
		dash();
		dot();
		dash();
		dot();
		longPause();
	}
	else if(Mchar == 'd'){
		longPause();
		dash();
		dot();
		dot();
		longPause();
	}
	else if(Mchar == 'e'){
		longPause();
		dot();
		longPause();
	}
	else if(Mchar == 'f'){
		longPause();
		dot();
		dot();
		dash();
		dot();
		longPause();
	}
	else if(Mchar == 'g'){
		longPause();
		dash();
		dash();
		dot();
		longPause();		
	}
	else if(Mchar == 'h'){
		longPause();
		dot();
		dot();
		dot();
		dot();
		longPause();		
	}
	else if(Mchar == 'i'){
		longPause();
		dot();
		dot();
		longPause();		
	}
	else if(Mchar == 'j'){
		longPause();
		dot();
		dash();
		dash();
		dash();
		longPause();	
	}
	else if(Mchar == 'k'){
		longPause();
		dash();
		dot();
		dash();
		longPause();		
	}
	else if(Mchar == 'l'){
		longPause();
		dot();
		dash();
		dot();
		dot();
		longPause();		
	}
	else if(Mchar == 'm'){
		longPause();
		dash();
		dash();
		longPause();		
	}
	else if(Mchar == 'n'){
		longPause();
		dash();
		dot();
		longPause();		
	}
	else if(Mchar == 'o'){
		longPause();
		dash();
		dash();
		dash();
		longPause();		
	}
	else if(Mchar == 'p'){
		longPause();
		dot();
		dash();
		dash();
		dot();
		longPause();		
	}
	else if(Mchar == 'q'){
		longPause();
		dash();
		dash();
		dot();
		dash();
		longPause();		
	}
	else if(Mchar == 'r'){
		longPause();
		dot();
		dash();
		dot();
		longPause();		
	}
	else if(Mchar == 's'){
		longPause();
		dot();
		dot();
		dot();
		longPause();		
	}
	else if(Mchar == 't'){
		longPause();
		dash();
		longPause();		
	}
	else if(Mchar == 'u'){
		longPause();
		dot();
		dot();
		dash();
		longPause();		
	}
	else if(Mchar == 'v'){
		longPause();
		dot();
		dot();
		dot();
		dash();
		longPause();		
	}
	else if(Mchar == 'w'){
		longPause();
		dot();
		dash();
		dash();
		longPause();		
	}
	else if(Mchar == 'x'){
		longPause();
		dash();
		dot();
		dot();
		dash();
		longPause();		
	}
	else if(Mchar == 'y'){
		longPause();
		dash();
		dot();
		dash();
		dash();
		longPause();		
	}
	else if(Mchar == 'z'){
		longPause();
		dash();
		dash();
		dot();
		dot();
		longPause();		
	}
	
}

void flash(){
	_delay_ms(30);
	turnLedOn();
	_delay_ms(30);
	turnLedOff();
	_delay_ms(30);
	turnLedOn();
	_delay_ms(30);
	turnLedOff();
	_delay_ms(30);
	turnLedOn();
	_delay_ms(30);
	turnLedOff();
}

ISR(PCINT0_vect) {
   //
   // pin change interrupt handler
   //
   static char chr;
   get_char(&serial_pins, serial_pin_in, &chr);

   morseIt(chr);

   static char message[] PROGMEM = "hello.ftdi.44.echo.interrupt.c: you typed ";
   put_string(&serial_port, serial_pin_out, (PGM_P) message);
   put_char(&serial_port, serial_pin_out, chr);
   put_char(&serial_port, serial_pin_out, 10); // new line
}

int main(void) {
   //
   // main
   //
   static char chr;
   //
   // set clock divider to /1
   //
   CLKPR = (1 << CLKPCE);
   CLKPR = (0 << CLKPS3) | (0 << CLKPS2) | (0 << CLKPS1) | (0 << CLKPS0);
   //
   // initialize output pins
   //
   set(serial_port, serial_pin_out);
   output(serial_direction, serial_pin_out);

   //
   // set up pin change interrupt on input pin
   //
   set(GIMSK, serial_interrupt);
   set (PCMSK0, serial_interrupt_pin);
   sei();

   //button input
   DDRB&=~_BV(2);
   //Enable pull up resistor
   PORTB|=_BV(2);

   //set ledpin as output
   output(serial_direction, led_pin);
   turnLedOff();

   //
   // main loop
   //
   while (1) {	
	  if(bit_is_clear(PINB, 2)){
		flash();
	  }

      put_char(&serial_port, serial_pin_out, chr);
      put_char(&serial_port, serial_pin_out, 10); // new line
	  }
}