/*
LEDcube
Firmware
for use with ATtiny2313
25-December-09

Distributed under Creative Commons 3.0 -- Attib & Share Alike
*/

/*
This test firmware lights up each LED for 1/2 second, starting with the top-front-right corner LED,
   and going to the bottom-back-left corner LED.
The orientation is:  with the serial-port connector facing to your right.
*/

/*
to program the ATtiny2313, execute the following command:
     make program-ledcubetest

If the microcontroller has never been programmed before,
the fuse bytes need to be programmed once:
	 make burn-fuse
*/


#include <avr/io.h>             // this contains all the IO port definitions
#include <avr/interrupt.h>      // definitions for interrupts
#include <avr/sleep.h>          // definitions for power-down modes
#include <avr/pgmspace.h>       // definitions or keeping constants in program memory


/*
The hardware for this project is as follows:
     ATtiny2313 has 20 pins:
Note: the orientation is:  with the serial-port connector facing to your right.
       pin 1   connects to serial port programming circuitry
       pin 2   PD0 - ground for bottom plane of 3x3 LEDs
       pin 3   PD1 - ground for middle plane of 3x3 LEDs
       pin 6   PD2 - ground for top plane of 3x3 LEDs
       pin 7   PD3 - +V for back-left LED of each plane
       pin 10  ground
       pin 12  PB0 - +V for front-right LED of each plane
       pin 13  PB1 - +V for middle-right LED of each plane
       pin 14  PB2 - +V for front-middle LED of each plane
       pin 15  PB3 - +V for middle-middle LED of each plane
       pin 16  PB4 - +V for front-left LED of each plane
       pin 17  PB5 - +V for middle-left LED of each plane -- also connects to serial port programming circuitry
       pin 18  PB6 - +V for back-right LED of each plane -- also connects to serial port programming circuitry
       pin 19  PB7 - +V for back-middle LED of each plane -- also connects to serial port programming circuitry
       pin 20  +3v
    All other pins are unused

    This firmware requires that the clock frequency of the ATtiny
      is the default that it is shipped with:  8.0MHz internal oscillator
*/


/*
The C compiler creates code that will transfer all constants into RAM when the microcontroller
resets.  Since this firmware has a table (imageTab) that is too large to transfer into RAM,
the C compiler needs to be told to keep it in program memory space.  This is accomplished by
the macro PROGMEM (this is used, below, in the definition for the imageTab).  Since the
C compiler assumes that constants are in RAM, rather than in program memory, when accessing
the imageTab, we need to use the pgm_read_byte() and pgm_read_dword() macros, and we need
to use the imageTab as an address, i.e., precede it with "&".  For example, to access
imageTab[3].TopFrontRow, which is a byte, this is how to do it:
     pgm_read_byte( &imageTab[3].TopFrontRow );
And to access imageTab[3].imageDuration, which is a double-word, this is how to do it:
     pgm_read_dword( &imageTab[3].imageDuration );
*/


// table of values for 3x3x3 LEDs
// 0 is off, 1 is on for each LED
// last element must have 0 duration
struct imageElement {
  unsigned char TopFrontRow;  // 3 bits:  top-front-left, top-front-mid, top-front-right
  unsigned char TopMidRow;    // 3 bits:  top-mid-left,   top-mid-mid,   top-mid-right
  unsigned char TopBackRow;   // 3-bits:  top-back-left,  top-back-mid,  top-back-right
  unsigned char MidFrontRow;  // 3-bits:  mid-front-left, mid-front-mid, mid-front-right
  unsigned char MidMidRow;	  // 3 bits:  mid-mid-left,   mid-mid-mid,   mid-mid-right
  unsigned char MidBackRow;	  // 3-bits:  mid-back-left,  mid-back-mid,  mid-back-right
  unsigned char BotFrontRow;  // 3-bits:  bot-front-left, bot-front-mid, bot-front-right
  unsigned char BotMidRow;	  // 3 bits:  bot-mid-left,   bot-mid-mid,   bot-mid-right
  unsigned char BotBackRow;	  // 3-bits:  bot-back-left,  bot-back-mid,  bot-back-right
  unsigned long int imageDuration;  // Duration for this element to be displayed before going to next element (divide by 10,000 to get seconds)
} const imageTab[] PROGMEM = {
  { 0b001, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b010, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b100, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b001, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b010, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b100, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b001, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b010, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b100, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b001, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b010, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b100, 0b000, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b001, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b010, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b100, 0b000, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b001, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b010, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b100, 0b000, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b001, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b010, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b100, 0b000, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b001, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b010, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b100, 0b000, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b001, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b010, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b100, 25000 },
  { 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000, 0b000,     0 },  // this is a dummy element for end of table (duration=0)
};


// This function delays the specified number of 1/10 milliseconds
void delay_one_tenth_ms(unsigned long int ms) {
  unsigned long int timer;
  const unsigned long int DelayCount=87;  // this value was determined by trial and error

  while (ms != 0) {
    // Toggling PD6 is done here to force the compiler to do this loop, rather than optimize it away
    for (timer=0; timer <= DelayCount; timer++) {PIND |= 0b01000000;};
    ms--;
  }
}


// This function displays a 3x3x3 image by multiplexing through the images for the 3 planes.
//   The multiplex rate is about 111Hz.
// This function also acts as a delay for the Duration specified.
void displayImage(int index) {
  unsigned long int duration = pgm_read_dword( &imageTab[index].imageDuration );
  unsigned char tempA, tempB, tempC, tempD;
  for (int i=0; i<(duration/(90*3*2)); i++) {
	// first we will turn on all of the LEDs that imageTab says to turn on for the top plane (but only for 30msec)
	tempA = pgm_read_byte( &imageTab[index].TopFrontRow );  // we now have 3 bits: top-front-left, top-front-mid, top-front-right -- these go to PB4, PB2, PB0, respectively
	tempB = tempA;
    tempC = tempA;
	tempA = tempA & 0b001; // this is top-front-right, which goes to PB0
	tempB = tempB & 0b010; // this is top-front-mid, which goes to PB2
	tempB = tempB << 1;    // the bit is now in bit 2 (ready for PB2)
	tempC = tempC & 0b100; // this is top-front-left, which goes to PB4
	tempC = tempC << 2;    // the bit is now in bit 4 (ready for PB4)
	tempD = tempA | tempB | tempC;
	tempA = pgm_read_byte( &imageTab[index].TopMidRow );    // we now have 3 bits: top-mid-left, top-mid-mid, top-mid-right -- these go to PB5, PB3, PB1, respectively
	tempB = tempA;
    tempC = tempA;
	tempA = tempA & 0b001; // this is top-mid-right, which goes to PB1
	tempA = tempA << 1;    // the bit is now in bit 1 (ready for PB1)
	tempB = tempB & 0b010; // this is top-mid-mid, which goes to PB3
	tempB = tempB << 2;    // the bit is now in bit 3 (ready for PB3)
	tempC = tempC & 0b100; // this is top-mid-left, which goes to PB5
	tempC = tempC << 3;    // the bit is now in bit 5 (ready for PB5)
	tempD = tempD | tempA | tempB | tempC;
	tempA = pgm_read_byte( &imageTab[index].TopBackRow );   // we now have 3 bits: top-back-left, top-back-mid, top-back-right -- these go to PD3, PB7, PB6, respectively
	tempB = tempA;
    tempC = tempA;
	tempA = tempA & 0b001; // this is top-back-right, which goes to PB6
	tempA = tempA << 6;    // the bit is now in bit 6 (ready for PB6)
	tempB = tempB & 0b010; // this is top-back-mid, which goes to PB7
	tempB = tempB << 6;    // the bit is now in bit 7 (ready for PB7)
	tempC = tempC & 0b100; // this is top-back-left, which goes to PD3
	tempC = tempC << 1;    // the bit is now in bit 3 (ready for PD3)
	tempD = tempD | tempA | tempB;
    PORTB |= tempD;
    PORTD |= tempC;
    PORTD &= ~(1<<PD2);  // turn on top plane by making bit 2 of PORTD Low
    delay_one_tenth_ms(30);
    PORTD |= (1<<PD2);   // turn off top plane by making bit 2 of PORTD High
    PORTB &= ~tempD;
    PORTD &= ~tempC;

	// now we will turn on all of the LEDs that imageTab says to turn on for the middle plane (but only for 30msec)
	tempA = pgm_read_byte( &imageTab[index].MidFrontRow );  // we now have 3 bits: mid-front-left, mid-front-mid, mid-front-right -- these go to PB4, PB2, PB0, respectively
	tempB = tempA;
    tempC = tempA;
	tempA = tempA & 0b001; // this is mid-front-right, which goes to PB0
	tempB = tempB & 0b010; // this is mid-front-mid, which goes to PB2
	tempB = tempB << 1;    // the bit is now in bit 2 (ready for PB2)
	tempC = tempC & 0b100; // this is mid-front-left, which goes to PB4
	tempC = tempC << 2;    // the bit is now in bit 4 (ready for PB4)
	tempD = tempA | tempB | tempC;
	tempA = pgm_read_byte( &imageTab[index].MidMidRow );    // we now have 3 bits: mid-mid-left, mid-mid-mid, mid-mid-right -- these go to PB5, PB3, PB1, respectively
	tempB = tempA;
    tempC = tempA;
	tempA = tempA & 0b001; // this is mid-mid-right, which goes to PB1
	tempA = tempA << 1;    // the bit is now in bit 1 (ready for PB1)
	tempB = tempB & 0b010; // this is mid-mid-mid, which goes to PB3
	tempB = tempB << 2;    // the bit is now in bit 3 (ready for PB3)
	tempC = tempC & 0b100; // this is mid-mid-left, which goes to PB5
	tempC = tempC << 3;    // the bit is now in bit 5 (ready for PB5)
	tempD = tempD | tempA | tempB | tempC;
	tempA = pgm_read_byte( &imageTab[index].MidBackRow );   // we now have 3 bits: mid-back-left, mid-back-mid, mid-back-right -- these go to PD3, PB7, PB6, respectively
	tempB = tempA;
    tempC = tempA;
	tempA = tempA & 0b001; // this is mid-back-right, which goes to PB6
	tempA = tempA << 6;    // the bit is now in bit 6 (ready for PB6)
	tempB = tempB & 0b010; // this is mid-back-mid, which goes to PB7
	tempB = tempB << 6;    // the bit is now in bit 7 (ready for PB7)
	tempC = tempC & 0b100; // this is mid-back-left, which goes to PD3
	tempC = tempC << 1;    // the bit is now in bit 3 (ready for PD3)
	tempD = tempD | tempA | tempB;
    PORTB |= tempD;
    PORTD |= tempC;
    PORTD &= ~(1<<PD1);  // turn on middle plane by making bit 1 of PORTD Low
    delay_one_tenth_ms(30);
    PORTD |= (1<<PD1);   // turn off middle plane by making bit 1 of PORTD High
    PORTB &= ~tempD;
    PORTD &= ~tempC;

	// now we will turn on all of the LEDs that imageTab says to turn on for the bottom plane (but only for 30msec)
	tempA = pgm_read_byte( &imageTab[index].BotFrontRow );  // we now have 3 bits: bot-front-left, bot-front-mid, bot-front-right -- these go to PB4, PB2, PB0, respectively
	tempB = tempA;
    tempC = tempA;
	tempA = tempA & 0b001; // this is bot-front-right, which goes to PB0
	tempB = tempB & 0b010; // this is bot-front-mid, which goes to PB2
	tempB = tempB << 1;    // the bit is now in bit 2 (ready for PB2)
	tempC = tempC & 0b100; // this is bot-front-left, which goes to PB4
	tempC = tempC << 2;    // the bit is now in bit 4 (ready for PB4)
	tempD = tempA | tempB | tempC;
	tempA = pgm_read_byte( &imageTab[index].BotMidRow );    // we now have 3 bits: bot-mid-left, bot-mid-mid, bot-mid-right -- these go to PB5, PB3, PB1, respectively
	tempB = tempA;
    tempC = tempA;
	tempA = tempA & 0b001; // this is bot-mid-right, which goes to PB1
	tempA = tempA << 1;    // the bit is now in bit 1 (ready for PB1)
	tempB = tempB & 0b010; // this is bot-mid-mid, which goes to PB3
	tempB = tempB << 2;    // the bit is now in bit 3 (ready for PB3)
	tempC = tempC & 0b100; // this is bot-mid-left, which goes to PB5
	tempC = tempC << 3;    // the bit is now in bit 5 (ready for PB5)
	tempD = tempD | tempA | tempB | tempC;
	tempA = pgm_read_byte( &imageTab[index].BotBackRow );   // we now have 3 bits: bot-back-left, bot-back-mid, bot-back-right -- these go to PD3, PB7, PB6, respectively
	tempB = tempA;
    tempC = tempA;
	tempA = tempA & 0b001; // this is bot-back-right, which goes to PB6
	tempA = tempA << 6;    // the bit is now in bit 6 (ready for PB6)
	tempB = tempB & 0b010; // this is bot-back-mid, which goes to PB7
	tempB = tempB << 6;    // the bit is now in bit 7 (ready for PB7)
	tempC = tempC & 0b100; // this is bot-back-left, which goes to PD3
	tempC = tempC << 1;    // the bit is now in bit 3 (ready for PD3)
	tempD = tempD | tempA | tempB;
    PORTB |= tempD;
    PORTD |= tempC;
    PORTD &= ~(1<<PD0);  // turn on bottom plane by making bit 0 of PORTD Low
    delay_one_tenth_ms(30);
    PORTD |= (1<<PD0);   // turn off bottom plane by making bit 0 of PORTD High
    PORTB &= ~tempD;
    PORTD &= ~tempC;
  }
}


int main(void) {
  DDRB = 0xFF;   // set all PortB pins as outputs
  DDRD = 0x7F;   // set all PortD pins as outputs
  PORTB = 0x00;  // all PORTB output pins Off
  PORTD = 0b00000111;  // PORTD3 output pin Off, PORTD2 and PORTD1 and PORTD0 on (grounds)


  for (int count=0; count<3; count++) {
    // loop through entire Image Table of Image Elements
    //   each Image Element consists of a 3 planes of 3x3 LED (each LED on or off) data and a Duration
    int i = 0;
    do {
      displayImage(i);
      i++;
    } while (pgm_read_byte(&imageTab[i].imageDuration) != 0);  // 0 signifies end of table
  }


  // Shut down everything and put the CPU to sleep
  MCUCR |= 0b00100000;   // SE=1 (bit 5)
  MCUCR |= 0b00010000;   // SM1:0=01 to enable Power Down Sleep Mode (bits 6, 4)
  delay_one_tenth_ms(10000);  // wait 1 second
  PORTB = 0x00;          // turn off all PORTB outputs
  PORTD = 0x00;          // turn off all PORTD outputs
  DDRB = 0x00;           // make PORTB all inputs
  DDRD = 0x00;           // make PORTD all inputs
  sleep_cpu();           // put CPU into Power Down Sleep Mode
}