#include <avr/io.h>
#include <util/delay.h>
#include <cpu_speed.h>
#include <macros.h>
#include <graphics.h>
#include <lcd.h>
#include "lcd_model.h"

void setup( void ) {
	set_clock_speed(CPU_8MHz);

	//	(a) Enable input from the joystick-up switch and joystick-down switch.
	CLEAR_BIT(DDRD, 1); //up
	CLEAR_BIT(DDRB, 7); //down


	//	(b) Initialise the LCD display using the default contrast setting.
	lcd_init(LCD_DEFAULT_CONTRAST);
	//	(c) Use one of the functions declared in "graphics.h" to display
	//	your student number, "n9829369", using the foreground colour,
	//	positioning the left edge of the text at 12 and the nominal top
	//	of the text at 18.
	draw_string(12, 18, "n9829369", FG_COLOUR);
	//	(d) Use one of the functions declared in "graphics.h" to copy the contents
	//	of the screen buffer to the LCD.
	show_screen();
}

//	(e) Declare a global variable of type int named Contrast and
//	initialise it to the default LCD contrast.
//int Contrast = uint8_t contrast;
//static uint8_t
int Contrast = LCD_DEFAULT_CONTRAST;

void process(void) {
	//	(f) Test pin corresponding to joystick-down switch. If closed,
	//	decrement Contrast by 9. If the result is less than zero,
	//	set Contrast to the maximum permitted LCD contrast value.
	if ( BIT_IS_SET(DDRB, 7) ) {
		Contrast = Contrast - 9;
		if ( Contrast < 128 ) Contrast = 255;
	}
	//	(g) Test pin corresponding to joystick-up switch. If closed,
	//	increment Contrast by 9. If the result is greater
	//	then the maximum permitted LCD contrast value, set Contrast
	//	to zero.
	if ( BIT_IS_SET(DDRD, 1) ) {
		Contrast = Contrast + 9;
		if ( Contrast > 255 ) Contrast = 128;
	}
	//	(h) Send a sequence of commands to the LCD to enable extended
	//	instructions, set contrast to the current value of Contrast,
	//	and finally retore the LCD to basic instruction mode.
	LCD_CMD( lcd_set_function, lcd_instr_extended );
	LCD_CMD( lcd_set_contrast, Contrast );
	LCD_CMD( lcd_set_function, lcd_instr_basic );



}


int main(void) {
	setup();

	for ( ;; ) {
		process();
		_delay_ms(100);
	}

	return 0;
}