//
//
// hello.ftdi.44.echomorse.c 
//
// 115200 baud FTDI character echo, with flash string, and morse replay
//
// set lfuse to 0x5E for 20 MHz xtal
//
// Addapted from Neil Gershenfeld's hello.ftdi.44.echo.c and Julia Eberts' hello.ftdi.44.blink.c
// 12/8/10
//


#include <avr/io.h>
#include <util/delay.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 delay
#define led_dot() _delay_ms(300) // LED dot on
#define led_dash() _delay_ms(900) // LED dash on
#define led_char() _delay_ms(300) // LED delay between dot or dash
#define led_word() _delay_ms(1200) // LED delay between word

#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_port PORTA
#define led_direction DDRA
#define led1_pin (1 << PA6)
#define led1_pin (1 << PA10)

#define max_buffer 25

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();
   //
   // char delay
   //
   bit_delay();
   }

void put_string(volatile unsigned char *port, unsigned char pin, char *str) {
   //
   // print a null-terminated string
   //
   static int index;
   index = 0;
   do {
      put_char(port, pin, str[index]);
      ++index;
      } while (str[index] != 0);
   }

void dot() {
   //
   //  Play a dot on the left light
   //
   set(led_port, led1_pin)
   led_dot()
   clear(led_port, led1_pin)
   led_char()
   }

void dash() {
   //
   //  Play a dash on the right light
   //
   set(led_port, led2_pin)
   led_dash()
   clear(led_port, led2_pin)
   led_char()
   }

void morse_code(char txchar) {
   //
   //  Translate char to morse - my C here is probably not right
   //
   if (txchar == 'a' or txchar == 'A') {dot(); dash();}
   if (txchar == 'b' or txchar == 'B') {dash(); dot(); dot(); dot();}
   if (txchar == 'c' or txchar == 'C') {dash(); dot(); dash(); dot();}
   if (txchar == 'd' or txchar == 'D') {dash(); dot(); dot();}
   if (txchar == 'e' or txchar == 'E') {dot();}
   if (txchar == 'f' or txchar == 'F') {dot(); dot(); dash(); dot();}
   if (txchar == 'g' or txchar == 'G') {dash(); dash(); dot();}
   if (txchar == 'h' or txchar == 'H') {dot(); dot(); dot(); dot();}
   if (txchar == 'i' or txchar == 'I') {dot(); dot();}
   if (txchar == 'j' or txchar == 'J') {dot(); dash(); dash(); dash();}
   if (txchar == 'k' or txchar == 'K') {dash(); dot(); dash();}
   if (txchar == 'l' or txchar == 'L') {dot(); dash(); dot(); dot();}
   if (txchar == 'm' or txchar == 'M') {dash(); dash();}
   if (txchar == 'n' or txchar == 'N') {dash(); dot();}
   if (txchar == 'o' or txchar == 'O') {dash(); dash(); dash();}
   if (txchar == 'p' or txchar == 'P') {dot(); dash(); dash(); dot();}
   if (txchar == 'q' or txchar == 'Q') {dash(); dash(); dot(); dash();}
   if (txchar == 'r' or txchar == 'R') {dot(); dash(); dot();}
   if (txchar == 's' or txchar == 'S') {dot(); dot(); dot();}
   if (txchar == 't' or txchar == 'T') {dash();}
   if (txchar == 'u' or txchar == 'U') {dot(); dot(); dash();}
   if (txchar == 'v' or txchar == 'V') {dot(); dot(); dot(); dash();}
   if (txchar == 'w' or txchar == 'W') {dot(); dash(); dash();}
   if (txchar == 'x' or txchar == 'X') {dash(); dot(); dot(); dash();}
   if (txchar == 'y' or txchar == 'Y') {dash(); dot(); dash(); dash();}
   if (txchar == 'z' or txchar == 'Z') {dash(); dash(); dot(); dot();}
   if (txchar == '1') {dot(); dash(); dash(); dash(); dash();}
   if (txchar == '2') {dot(); dot(); dash(); dash(); dash();}
   if (txchar == '3') {dot(); dot(); dot(); dash(); dash();}
   if (txchar == '4') {dot(); dot(); dot(); dot(); dash();}
   if (txchar == '5') {dot(); dot(); dot(); dot(); dot();}
   if (txchar == '6') {dash(); dot(); dot(); dot(); dot();}
   if (txchar == '7') {dash(); dash(); dot(); dot(); dot();}
   if (txchar == '8') {dash(); dash(); dash(); dot(); dot();}
   if (txchar == '9') {dash(); dash(); dash(); dash(); dot();}
   if (txchar == '0') {dash(); dash(); dash(); dash(); dash();}
   if (txchar == ' ') {led_word();}          
   }             

int main(void) {
   //
   // main
   //
   static char chr;
   static char buffer[max_buffer] = {0};
   static int index;
   //
   // 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);
   //
   // initialize LED pin
   //
   clear(led_port, led1_pin);
   output(led_direction, led1_pin);
   clear(led_port, led2_pin);
   output(led_direction, led2_pin);
   clear(led_port, led3_pin);
   output(led_direction, led3_pin);
   //
   // main loop
   //
   index = 0;
   while (1) {
      get_char(&serial_pins, serial_pin_in, &chr);
      put_string(&serial_port, serial_pin_out, "hello.ftdi.44.echo.c: you typed \"");
      buffer[index++] = chr;
      if (index == (max_buffer-1))
         index = 0;
      put_string(&serial_port, serial_pin_out, buffer);
      put_char(&serial_port, serial_pin_out, '\"');
      put_char(&serial_port, serial_pin_out, 10); // new line
      morse_code(chr)
      }
   }