// Nicole Wang [MAS.863.12]
// 10.23.12
// From Jeremy Scott + Neil Gershenfeld
// LED Button Blink Program

#include <avr/io.h>
// #define F_CPU 1e6
// Defined in Makefile.
#include <util/delay.h>
#include <avr/interrupt.h>

#define TRUE 1
#define FALSE 0

int main() {
  // Set clock divider to /1.
  // Lines 15-16 are from Neil's hello.ftdi.44.echo.c code.
  //
  CLKPR = (1 << CLKPCE);
  CLKPR = (0 << CLKPS3) | (0 << CLKPS2) | (0 << CLKPS1) | (0 << CLKPS0);
  
  // Button = PA7.
  // Green LED = PA2; red LED = PA3.

  PORTA |= _BV(PA7); // Turn button pull-up resistor on.
  DDRA |= _BV(PA2);  // Enables output on the green LED pin.
  PORTA |= _BV(PA2); // Turns green LED on.
  DDRA |= _BV(PA3);  // Enables output on the red LED pin.
  PORTA |= _BV(PA3); // Turns red LED on.
  
  
  int count = 0;
  
  // LOOP
  while (TRUE) {
    // If the button is not pushed:
    if ((PINA & _BV(PA7))) {
      PORTA &= ~_BV(PA2); // Turns green LED off.
      PORTA &= ~_BV(PA3); // Turns red LED off.
    // Else turn the LED on:
    } else {
      PORTA |= _BV(PA2);
      _delay_ms(500);
      PORTA &= ~_BV(PA2);
      _delay_ms(1000);
      count++;
      int i;
      for (i = 1; i <= count; i++) {
        if (i%2 == 0) {
          PORTA |= _BV(PA2);
          _delay_ms(250);
          PORTA &= ~_BV(PA2);
          _delay_ms(250);
        } else {
          PORTA |= _BV(PA3);
          _delay_ms(250);
          PORTA &= ~_BV(PA3);
          _delay_ms(250);
        }
      }
      if (count>=4) {
        count = 0;
      }
    }
  }

}