/*

Cross-fading Cylon Eyes
A PWM demo

*/

// ------- Preamble -------- //
#include <avr/io.h>                        /* Defines pins, ports, etc */
#include <util/delay.h>                     /* Functions to waste time */
#include "pinDefines.h"


int main(void) {

  uint8_t thisEye = 0;
  uint8_t nextEye = 1;
  uint8_t brightness = 0;
  int8_t direction = 1;
  uint8_t i;

  // -------- Inits --------- //

  // Init all LEDs
  LED_DDR = 0xff;
  SPEAKER_DDR |= (1 << SPEAKER);
  // ------ Event loop ------ //
  while (1) {

    // PWM
    for (brightness = 0; brightness < 255; brightness++) {
      for (i = 0; i < 255; i++) {
        if (i < brightness) {
          LED_PORT &= ~(1 << thisEye);                     /* dimming */
          LED_PORT |= (1 << nextEye);              /* getting brighter */
        }
        else {
          LED_PORT |= (1 << thisEye);
          LED_PORT &= ~(1 << nextEye);
        }
        LED_PORT &= ~(1 << thisEye);            /* make sure it's off */
      }
    }

    // Cylon Scan
    thisEye += direction;                       /* move on to next eye */

    if (thisEye == 0) {
      direction = 1;
    }
    if (thisEye == 7) {
      direction = -1;
    }

    nextEye = thisEye + direction;


  }                                                  /* End event loop */
  return 0;                            /* This line is never reached */
}