#include <avr/io.h> 
#include <avr/interrupt.h>
#define F_CPU 16000000UL
#include <util/delay.h>
#include <string.h>
#include <stdio.h>
#include "lcd_c.c"

// ------------------ DEFINICE --------------------------

#define SPI_PORT	PORTB
#define SPI_DIR		DDRB
#define SPI_PIN		PINB
#define SPI_DATA	SPDR

#define SPI_CLK		(1<<7) 
#define SPI_MOSI	(1<<5)
#define SPI_MISO	(1<<6)
#define SPI_CS		(1<<4)


#define fdisplay 0x2fff
#define prumerovani	15			//hodnota prumerovaciho filtru na odstarneni sumu

// ------------------ GOBALNI PROMENNE -----------------
int Acc_X, Acc_Y, Acc_Z;	//vysledna hodnota zrychleni
int prum_X, prum_Y, prum_Z; //
uint8_t prum = 0;

char text[15];

// ------------------ FUNKCE ---------------------------
uint8_t SPI_MasterInit(void);
unsigned int SPI_SR (uint8_t DataIn, uint8_t AddressIn);
void SPI_Send (uint8_t datain);
void TimerInit(void);
uint16_t uprava(uint16_t data1, uint16_t data2);
// ------------------ MAIN -----------------------------
int main (void)
{
uint16_t temp =0;


lcd_init ();
lcd_clrscr ();


if (SPI_MasterInit()){
	//chybova hlaska
	lcd_gotoxy(0,0);
	lcd_puts("Chyba komunikace");
	for (;;);	//neklonecna smycka
	}

lcd_gotoxy(0,0);
lcd_puts("ACC  X    Y    Z");

TimerInit();
 


sei ();	//povoleni preruseni

for (;;){
	
	
	temp = ((SPI_SR(0x00,0b00010001))&0x00ff);	
	prum_X = (prum_X + uprava (temp,(SPI_SR(0x00,0b00010000))) )/2;

	temp = ((SPI_SR(0x00,0b00010011))&0x00ff);
	prum_Y = (prum_Y + uprava (temp,(SPI_SR(0x00,0b00010010))) )/2; 

	temp = ((SPI_SR(0x00,0b00010101))&0x00ff);
	prum_Z = (prum_Z + uprava (temp,(SPI_SR(0x00,0b00010100))) )/2; 
	//prubezny vypocet prumeru z nahranych dat
	if (prum == prumerovani)
		{
		Acc_X = prum_X;
		Acc_Y = prum_Y;
		Acc_Z = prum_Z;
		prum = 0;
		}
		else
			prum ++;
	
	_delay_ms (5);//prodleva mezi stahnutim mereni (vzorkovaci frekvence cca 200 Hz)
	
	}


}

//------------------------ SPI nastavení portů a rozhraní------------------------------

uint8_t SPI_MasterInit(void)
{
SPI_DIR |= (SPI_CLK | SPI_MOSI | SPI_CS);		//konfig smeru pinu
SPI_PORT |= SPI_CS;								// deaktivovani slave u SPI

// Enable SPI, Master, set clock rate 
SPCR = (1<<SPE)|(1<<MSTR)|(0<<SPR1)|(1<<SPR0)|(0<<CPOL)|(1<<CPHA)|(1<<DORD);

SPI_SR(0x04,0b00110110);	//nastavi rozliseni 64LSB/G

//zjisti jestli se zapsalo nastaveni = zjednoduseny funkcni test
if ( ((SPI_SR(0,0b00010110))&0x00FF) == 0x04)
	return 0;	
  else
  	return 1;	//chyba komunikace s akceleromertem
}
//---------------------- inicializace casovace pro vypis na displej ------------
void TimerInit(void)

{

// TIMER1 :
	OCR1A = fdisplay;
  	TCCR1B |= (0<<CS12)|(1<<CS11)|(1<<CS10) ;
  	TIMSK |= 1<<OCIE1A;		//povolim preruseni pri porovnani s OCR1A

 
}

//------------------------ odesle a prijme 16 bit. slovo pres SPI --------------------

unsigned int SPI_SR (uint8_t DataIn, uint8_t AddressIn)
{
unsigned int dataout = 1;

//odesle prikaz

PORTB &= ~(1<<PD0);					//aktivuje SS

// odeslani LSB 
SPI_Send (DataIn);

while(!(SPSR & (1<<SPIF)));			// ceka nez jsou data odeslana

// odeslani MSB
SPI_Send (AddressIn) ;

while(!(SPSR & (1<<SPIF)));			// ceka nez jsou data odeslana


PORTB |= (1<<PD0);					//deaktivuje SS

_delay_ms (10);


// odesle prazdne ramece aby prijmul odpoved

PORTB &= ~(1<<PD0);					//aktivuje SS

SPI_Send (0xff);

while(!(SPSR & (1<<SPIF)));			// ceka nez jsou data prijata

dataout = SPI_DATA;						//ulozeni MSB

SPI_Send (0xff);

while(!(SPSR & (1<<SPIF)));			// ceka nez jsou data prijata
dataout = (SPI_DATA |(dataout<<8));		//ulozeni LSB

PORTB |= (1<<PD0);					//deaktivuje SS

return dataout;
}


// ---------------------------- nizkourovnove odeslani dat pres SPI ------------------------
void SPI_Send (uint8_t datain)
{
SPSR |= (1<<SPIF);
SPI_DATA = (datain>>8) & 0x00ff ;
}
//------------------------------ upravi cislo do formatu 16bit 2. doplnku------------------------------
uint16_t uprava(uint16_t data1, uint16_t data2)
{
int16_t pom;
uint16_t pom2;
pom2 = ( (data2<<8) | (data1&0x00ff) );
pom = ((pom2)<<6);	//posun do formy 2.doplnku 16ti bitoveho
return (pom/64); 				// bitovy posuv 6x = 2na6 tzn podelim 64

}
//------------------------------ preruseni od OCR1A ------------------------------

ISR(TIMER1_COMPA_vect)
{

//pravidelne vypsani merenych dat na display	
	lcd_gotoxy(0,1);
	sprintf(text,"  %4d %4d %4d",Acc_X, Acc_Y, Acc_Z);
	lcd_puts(text);


	
	TCNT1 = 0;
}