/*
 * Digital I/O (dual 7-segment LED) lab program that demonstrates
 * driving all segments of a dual 7-segment display directly, that
 * is, without the use of a decoder like the 7447.
 *
 * This program demonstrates counting down from 20 to 0, in real-time
 * (delaying one second per count).
 *
 * PORTB is used to display the left digit, and PORTC is used for the
 * right.
 *
 * The dual 7-segment LED board that we are using in this lab has the
 * segments for a..g on bits 0..6, respectively, and the decimal point
 * on bit 7.  One digit occupies one eight-bit (10pin, incl. VTG & GND)
 * STK500-style connector.
 *
 * Last Modified 2010/09/28 17:10 (ebw)
 */

#include <avr/io.h>       // for PORTx, DDRx, AD*, etc.
#include <util/delay.h>   // for _delay_ms()

/*
 * Bit patterns for the digits 0..9 that can be written directly to the port
 * connected to one digit of our common-anode 7-segment LED display board.
 */
//                     pgfedcba
#define PATTERN_0    0b11000000
#define PATTERN_1    0b11111001
#define PATTERN_2    0b10100100
#define PATTERN_3    0b10110000
#define PATTERN_4    0b10011001
#define PATTERN_5    0b10010010
#define PATTERN_6    0b10000011
#define PATTERN_7    0b11111000
#define PATTERN_8    0b10000000
#define PATTERN_9    0b10011000

#define PATTERN_DP   0b01111111

/*
 * Array indexed 0..9 containing bit patterns for digits 0..9.
 * HINT: this can make displaying digits much easier than using "if" or
 *       "switch/case" statements.s
 */
int digitPatterns[10] = { PATTERN_0,
                          PATTERN_1,
                          PATTERN_2,
                          PATTERN_3,
                          PATTERN_4,
                          PATTERN_5,
                          PATTERN_6,
                          PATTERN_7,
                          PATTERN_8,
                          PATTERN_9 };
                     
void init(void)
{
    DDRB = 0xFF;  // all of PORTB is outputs
    DDRC = 0xFF;  // all of PORTC is outputs
}


int main(void)
{
    init();

    PORTB = PATTERN_2;  // display an initial value for testing
    PORTC = PATTERN_7;

    while (1) {

/*
      for ( FIXME ) {
        PORTB = FIXME;
        PORTC = FIXME;

        _delay_ms(100);
      }
*/
    }

    return 0;        // never executed...
}