/* This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <stdint.h> // Standard Integer Types
#include <stdio.h> // Standard IO facilities
#include <stdlib.h> // General utilities
#include <stdbool.h> // Boolean
#include <string.h> // Strings

#include <avr/io.h> // AVR device-specific IO definitions
#include <util/delay.h> // Convenience functions for busy-wait delay loops
#include <avr/interrupt.h> // Interrupts
#include <avr/wdt.h> // Watchdog timer handling
#include <avr/pgmspace.h> // Program Space Utilities
#include <avr/sleep.h> // Power Management and Sleep Modes

#include "uart.h" // basic UART functions
#include "main.h" // main definitions

/* switch off LED */
void led_off(void)
{
	LED_PORT &= ~(1<<LED_IO); // remove power to LED
}

/* switch on LED */
void led_on(void)
{
	LED_PORT |= (1<<LED_IO); // provide power to LED
}

/* toggle LED */
void led_toggle(void)
{
	LED_PIN |= (1<<LED_IO);
}

/* disable watchdog when booting */
void wdt_init(void) __attribute__((naked)) __attribute__((section(".init3")));
void wdt_init(void)
{
	MCUSR = 0;
	wdt_disable();

	return;
}

/* initialize GPIO */
void io_init(void)
{
	/* use UART as terminal */
	uart_init();
	stdout = &uart_output;
	stdin  = &uart_input;

	/* gpio */
	/* LED */
	LED_DDR |= (1<<LED_IO); // LED is driven by pin (set as output)
	led_off();

	sei(); /* enable interrupts */
}

int main(void)
{
	io_init(); // initialize IOs

	while (true) { // endless loop for micro-controller
		/* blinking LED example */
		led_toggle();
		_delay_ms(500);
	}
	return 0;
}