/*
 * Digital I/O (dual 7-segment LED) lab program.
 *
 * This program demonstrates the use of a (dual) 7-segment LED display.
 * Initially it displays just one number, but provides a template for making
 * it count up from 00 to 99, pausing 0.1 second between numbers.
 *
 * When using an LED decoder chip like the 7447, only four data pins are
 * needed to represent the values 0-9 on one display digit, as opposed to one
 * pin for each digit (so, 7 total).  Because there are two digits and each
 * requires four bits, all eight pins can share one port, and we're using PORTB
 * for this in the template below.
 *
 * Last Modified 2010/09/29 15:25 (ebw)
 */

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

void init(void)
{
    DDRB = 0xFF;       // all eight bits are outputs
}


/*
 * Count from 00 to 99, delaying 0.1sec in between.
 */
int main(void)
{
    init();				// call init to set up PORTB pins

    PORTB = 0x55;      // drive test value onto display

    while (1)
    {
/******
        uint8_t counter;
	
        for ( counter ... FIXME )
        {
            // FIXME: do something here with counter to generate inputs
            // to decoders on PORTB

            PORTB = FIXME...

            _delay_ms(100);
        }
*******/
    }

    return 0;        // never executed...
}