/** \file main.c
 * \brief Program Template
 * 
 * $Id: avr_auto.c 40 2006-10-28 17:27:51Z robocon2006 $
 */
/**
 * Hong Kong Univerisity Of Science and Technology, Copyright (c) 2005-2007
 * Code for Robocon Electronics Quickstart Course
 */

// These are two very basic definition
// F_CPU specify the CPU Frequency, which is used in <util/delay.h>
#define F_CPU 14745600
// This one will give you access to the SFR
#include <avr/io.h>
#include <util/delay.h>

int main( void )
{
    // Output
    //    High
    //    Low
    // Input
    //    Pull Up
    //    Floating

    // PROG: C3
    // Mode: Pull up high
    DDRC &= ~_BV(3);
    PORTC |= _BV(3);

    // LED : E3 
    // Turn on
    // Mode: Output Low
    // Turn off
    // Mode: Output High
    DDRE |= _BV(3); // Make E3 into output mode 

    // Variable Type:
    // +unsigned
    // +signed
    // char,    int, short, long, long long, float, double, void*
    // char   8, 
    // int 32 on PC, but 16 here
    // short 16 in PC
    // long 32 bits
    // long long 64 bits
    // 8 bits for each register

    uint8_t state = 1;
    while (1) {
        switch (state) {
        case 1:
        // Button Down: Pin -> 0V
        // Button Up: Pin -> 5V
            if (~PINC & _BV(3)) {
                state = 2;
                PORTE |= _BV(3);
            }
        break;
        case 2:
            if (PINC & _BV(3)) {
                state = 3;
            }
        break;
        case 3:
            if (~PINC & _BV(3)) {
                state = 4;
                PORTE &= ~_BV(3);
            }
        break;
        case 4:
            if (PINC & _BV(3)) {
                state = 1;
            }
        break;
        }
    }
}