//comment out the following line if not using the bootloader
//#define USING_BOOTLOADER


//set F_CPU if not set already, dependent on use of boot loader
#ifndef F_CPU

#ifdef USING_BOOTLOADER
#define F_CPU 2000000UL
#else
#define F_CPU 8000000UL
#endif

#endif



#include <util/delay.h>
#include <avr/io.h>
#include <avr/interrupt.h>

#include "U0_LCD_Driver.h"


//////////////
//globals   //
//////////////


//////////////
//prototypes//
//////////////
void SetupInterrupts(void);
void BootLoaderFixes(void);
void PlayA(void);



////////
//MAIN//
////////
int main(void)
{

	#ifdef USING_BOOTLOADER
	BootLoaderFixes();
	#endif

	/* Initialize and Clear the LCD */
	LCD_Init();
	LCD_WriteDigit('N',5);

	//Setup All Pushbuttons
	DDRB  &= ~0b11010000;  //set B4,B6,B7 as inputs
	DDRE  &= ~0b00001100;  //set all to inputs

	PORTB |=  0b11010000;  //enable pull up resistors on B4,B6,B7
	PORTE |=  0b00001100;  //enable pull up resistor on pin E2,E3



	//Setup Output for Music
	DDRB |= (1<<5); 	//enable PORTB5 as output
	DDRB |= (1<<0); 	//enable PORTB0 as output for the first LED
	DDRB |= (1<<1); 	//enable PORTB1 as output for the second LED

	SetupInterrupts();	//setup the interrupts
	sei();				//enable global interrupts

	PlayA(); 			//play A when program starts running

	for(;;)				//flash led on pin B1 every second
	{
		PORTB ^= (1<<1);
		_delay_ms(1000);
	}
}

////////////////////////
//Function Definitions//
////////////////////////


void SetupInterrupts(void)
{
	//Setup for Center Button Interrupt
	PCMSK1  |= (1<<PCINT12); //Unmask bit for Center Button on Butterfly, PB4->PCINT12 to allow it to trigger interrupt flag PCIF1
	EIMSK   = (1<<PCIE1);    //Enable interrupt for flag PCIF1
}


//This performs adjustments needed to undo actions of Butterfly boot loader
void BootLoaderFixes(void)
{
	//Boot loader Disables E2 and E3 digital input drivers, which are used for left and right
	//The following code re-enables them by clearing the appropriate disable bits
	DIDR1 &= ~((1<<AIN0D)|(1<<AIN1D));
}


////////////////////
// ISR DEFINITIONS//
////////////////////


ISR(PCINT1_vect) 		//remember this is called on pin change 0->1 and 1->0
{
	static uint8_t pinBPrev=1; //for storing previous value of port to detect

	PlayA(); //play note every time interrupt is called

	//toggle PORTB0 based on center button status being newly pressed, but not when it is released
	if(((PINB     & (1<<4))  == 0) &&
	((pinBPrev & (1<<4))  != 0))
	{
		//if button pressed (bit is zero) and previous it wasn't
		PORTB ^= (1<<0); //toggle led on B0
		LCD_WriteDigit('C',5);
	}
	else
	{
		//do nothing
	}

	pinBPrev = PINB; //save button status
}


void PlayA()
{
	for (uint8_t i = 0 ; i < 110 ; ++i)
	{
		PORTB ^= (1<<5);            //toggle PORTB5
		_delay_us(500);
		_delay_us(500);
		_delay_us(136);
	}
}