/*
 * lab5.c
 *
 * Created: 10/23/2019 6:18:50 PM
 * Author : Nick Grant
 */

#include <avr/io.h>
#include "scheduler.h"

#define SET_BIT(p,i) ((p) |= (1 << (i)))
#define CLR_BIT(p,i) ((p) &= ~(1 << (i)))
#define GET_BIT(p,i) ((p) & (1 << (i)))
#define SHIFT_REG PORTA

void transmit_data(unsigned char data){
	unsigned char tmp = data;
	// SER = 0, RCLK = 1, SRCLK = 2, SRCLR = 3
	SET_BIT(SHIFT_REG, 3);			// set SRCLR high
	CLR_BIT(SHIFT_REG, 1);			// set RCLK low
	for(int i = 0; i < 8; i++){
		CLR_BIT(SHIFT_REG, 2);			// set SRCLK low
		tmp = GET_BIT(data, i);
		if(tmp) {
			SET_BIT(SHIFT_REG, 0);	// set SER to data to be transmitted
		}
		else {
			CLR_BIT(SHIFT_REG, 0);
		}
		SET_BIT(SHIFT_REG, 2);			// set SRCLK high
	}

	SET_BIT(SHIFT_REG, 1);				// set RCLK high
	CLR_BIT(SHIFT_REG, 3);				// set SRCLR low
}

unsigned long tasksPeriod_Sequence = 100;
unsigned long tasksPeriodGCD = 100;
unsigned char tasksNum = 1;
task tasks[1];

unsigned char temp, btnAdd, btnSub = 0x00;
enum ADD_SUB {AS_START, AS_WAIT, AS_ADD, AS_SUB, AS_RESET};
int TickFct_AS (int state) {
	btnAdd = ~(PINB & 0x01);
	btnSub = ~(PINB & 0x02);
	switch(state) {
		case AS_START:
			state = AS_WAIT;
			break;
		case AS_WAIT:
			if (btnAdd) {
				if (btnSub) {
					state = AS_RESET;
				}
				state = AS_ADD;
			}
			else if (btnSub) {
				if (btnAdd) {
					state = AS_RESET;
				}
				state = AS_SUB;
			}
			else {
				state = AS_WAIT;
			}
			break;
		case AS_ADD:
			state = AS_WAIT;
			break;
		case AS_SUB:
			state = AS_WAIT;
			break;
		case AS_RESET:
			state = AS_WAIT;
			break;
		default:
			state = AS_START;
			break;
	}
	switch(state) {
		case AS_START:
			temp = 0x00;
			transmit_data(0x55);
			break;
		case AS_WAIT:
			break;
		case AS_ADD:
			if (temp < 0xFF) {
				temp++;
			}
			transmit_data(temp);
			break;
		case AS_SUB:
			if (temp > 0x00) {
				temp--;
			}
			transmit_data(temp);
			break;
		case AS_RESET:
			temp = 0x00;
			transmit_data(temp);
			break;
		default:
			break;
	}

	return state;
};

int main(void)
{
	DDRA = 0xFF; PORTA = 0x00;
	DDRB = 0x00; PORTB = 0xFF;
	DDRC = 0xFF; PORTC = 0x00;

    TimerSet(50);
	TimerOn();
	// transmit_data(0xFA);
	tasks[0].TickFct = &TickFct_AS;
	tasks[0].state = AS_START;
	tasks[0].period = 100;
	tasks[0].elapsedTime = 0;
}