/*
 * CTHN.de MiniLEDCube
 *
 *  By Kai Lauterbach (klaute at web dot de) 11/2011
 *
 *  Based on http://mosfetkiller.de/?s=miniledcube
 *
 *  License: General Public License (GPL v3)
 *
 */

#include "main.h"

/*! \brief Initialize the AVR.
 */
static inline void init(void)
{
  // Init ports
  DDRB  = 0xFF;    // PB0-PB7: LED 1-8 (Kathode)
  PORTB = 0xFF;    // HIGH
  DDRD  = 0x78;    // PD6: LED 9 (Kathode); PD5-PD3: A-C (Anode)
  PORTD = 0x40;
  // Setup Timer-Interrupt "TIMER1" compare match
  // Refresh-rate is 100Hz of the whole LEDCube.
  // The timer fires at 300Hz.
  // Set the compare value to
  // 625d = 0x271
  OCR1A = 0x271;
  // Set prescaler to 64 and CTC mode
  TCCR1B = (1 << CS11) | (1 << CS10) | (1 << WGM12);
  sei(); // Enable interrupts global
}


/*! \brief Main loop
 */
int __attribute__((OS_main)) main()
{
  uint8_t level = 0x00;
  uint8_t frmnum = 0x00;
  uint8_t delay = 0x00;
  // Initialize the AVR and the USB connection.
  init();
  init_usb();

  // main loop
  for (;;) {
    usbPoll(); // keep connected

    if (TIFR & (1 << OCF1A)) {
      TIFR = (1 << OCF1A);
      cli();

      if (!(--delay)) { // decrease the counter and check if we are done with waiting
        if (frmnum == MAX_EEPROM_FRAMES) {
          if (mode == MODE_ANIMATION_SINGLE) {
            mode = MODE_ANIMATION_STOP;  // stop the animation after we have reached the 31th frame
          }

          frmnum = 0; // always start at the first frame
        } else {
          if (mode) {
            // if we are in an animation mode we have to load a frame out of the eeprom
            // and increase the counter
            frame.all = eeprom_read_dword(&eep_anim[frmnum]);
            frmnum++;
          }
        }

        // Just shift right by 24 instead of 27 to multiply the delay by 8.
        // Possible delays are 8 16 24 32 and so on. A zero delay isn't possible.
        // Zero means that a delay of 255 happens because the delay variable was decreased first before testing
        // it's zero value.
        delay = frame.bytes[3] & 0xf8;
      }

      // PORTD = __, 9, C, B, A, D+, D-, __
      PORTD &= ~((1 << PORTD5) | (1 << PORTD4) | (1 << PORTD3) | (1 << PORTD2)); // delete bit 3 to 6 (bit 3 to 5 = layer 0 to 2
      // PORTB = 1..8
      uint32_t tmp_frame = (frame.all >> (uint8_t)(level * 9));
      // 0 = led is on, 1 = led is off
      PORTB = ~((uint8_t)tmp_frame);

      if (!(tmp_frame & 0x100)) {
        PORTD |= (1 << PORTD6);  // turn the 9th LED off
      } else {
        PORTD &= ~(1 << PORTD6);  // turn the 9th LED on
      }

      // set the current level to high
      // at this point the LED pins are up to date so it's
      // safe to re-enable the level wire (A/B/C)
      // this prevents weird LED flashing which is not defined
      // in the animation frame
      PORTD |= ((1 << level) << 3); // set the current level
      // rotate through the 3 level
      level++;

      if (level > 2) {
        level = 0;
      }

      sei();
    }
  }
}