#include <p18f4550.h>
#include <delays.h>

#pragma config WDT = OFF, FOSC = INTOSC_HS, LVP=OFF

unsigned char val=0;

void picdelay (unsigned char n);
void ledonoff ();
unsigned char spi_r(unsigned char reg);
void spi_w(unsigned char regaddr, unsigned char regdata);

void main (void)
{

 // Make all bits on the Port D (LEDs) output bits.
 TRISD = 0;

//initializing SPI operation
SSPSTAT=0xC0; //11xxxxxx  (x = don't care)
SSPCON1=0x30; //0011xxxx  (x = don't care)

//Enable I/O
//SDO must have TRISC<7> bit cleared
TRISCbits.TRISC7=0;
//SCK must have TRISB<1> bit cleared.
TRISBbits.TRISB1=0;

//Set up MMA7455L operation mode by writing to hex addr 16, hex value 05 (2g, 4 wires)
spi_w(22,5); // 22 = 0x16, 5 = 0x05
 
 
while (1) {
	val = spi_r(22); // read value back from register and if expected value flash the LED
	if(val==5){ledonoff();}
			};

}// End of the main program


//SPI write command function reg - 1rrrrrrx (bit 7 is 1, next 6 bits reg address and a don't care)
void spi_w(unsigned char regaddr, unsigned char regdata)
{
	unsigned char tmp;
	PORTDbits.RD6 = 0; // pull the CS low to start SPI transmission
	SSPBUF=(((regaddr&0x3F)<<1)|0x80); // send register address to the accelerometer with write command
	while(!SSPSTATbits.BF);// wait for transfer
	tmp=SSPBUF; // reading SSPBUF clears the BF bit
	SSPBUF=regdata; // send data into the accelerometer register
	while(!SSPSTATbits.BF);
	tmp=SSPBUF; // reading SSPBUF clears the BF bit
	PORTDbits.RD6 = 1; // pull the CS high to stop SPI transmission
}


//SPI read function (send read register commands to the accelerometer and output resultant read byte)
unsigned char spi_r(unsigned char reg)
{
	unsigned char temp;
	PORTDbits.RD6 = 0; // pull the CS low to start transmission
	SSPBUF=((reg&0x3F)<<1); // // send register affress to the accelerometer with read command
	while(!SSPSTATbits.BF);// wait for transmit to finish
	temp=SSPBUF; // reading SSPBUF clears the BF bit
	while(!SSPSTATbits.BF); // wait for receive to finish
	temp=SSPBUF; // reading SSPBUF clears the BF bit
	PORTDbits.RD6 = 1; // pull the CS high to stop transmission
	return temp;

}

//SPI write command function
void spi_w(unsigned char reg, unsigned char data)
{ unsigned char x;
  CS=0;
  SSPBUF=(((reg &0x3F)<<1)|0x80);
  while (!SSPIF);  //wait for transmission complete
  x=SSPBUF;  //dummy read
  SSPBUF=data;
  while (!SSPIF);  //wait for transmission complete
  x=SSPBUF;
  CS=1;
}

//SPI read function

unsigned char spi_r(unsigned char reg)
{ unsigned char x;
  CS=0;
  SSPBUF = 0x00;                  // initiate bus cycle
  while ( !SSPIF );      // wait until cycle complete
  CS=1;
  return ( SSPBUF );              // return with byte read 
}

char Xdata
while (1) {
  Xdata=spi_r(0x06); //Read X output from Sensor
  DelayUs(10);
if(Xdata<=0x00)LED=1;
else LED=0;
			}
}

while (1) {
	val=0;// reset value
	PORTDbits.RD7 = 0;// turn LED ON
	val = spi_r(22); // read value from register
	if(val==5){PORTDbits.RD7 = 1;}// turn LED OFF
	else if(val!=5) {PORTDbits.RD7 = 0;}// turn LED ON
			};

void initialise_SPI()
{
   SSPEN = 0;            //Enable bit must be cleared to configure SPI
   
   TRISC = TRISC | 0b00010000;   //Setup the TRIS register
   
   CKP = 0;            //IDLE state for clock is a low level
   CKE = 1;            //Output data changes on clock transition from active to idle
   SMP = 0;            //Input data sampled at the middle of data output time
   
   SSPCON1 = SSPCON1 | 0b00000010;   //Speed: Fosc/64
   
   SSPEN = 1;            //Enable the serial port 
}

//SPI write command function
void spi_w(unsigned char reg, unsigned char data){
  unsigned char x;
  CS=lo;
  SSPBUF=(((reg &0x3F)<<1)|0x80); 
  while (!SSPIF);  //wait for transmission complete
  x=SSPBUF;  //dummy read
  SSPBUF=data;
  while (!SSPIF);  //wait for transmission complete
  x=SSPBUF;
  CS=hi;
}

//SPI read function

unsigned char spi_r(unsigned char reg){
  CS=lo;
  SSPBUF = 0x00;                  // initiate bus cycle
  while ( !BF );      // wait until cycle complete
  CS=hi;
  return ( SSPBUF );              // return with byte read 
}

unsigned char spi_r(unsigned char reg){
  CS=lo;
  SSPBUF = 0x00;                  // initiate bus cycle
  while ( !BF );      // wait until cycle complete
  CS=hi;
  return ( SSPBUF );              // return with byte read 
}

unsigned char spi_r(unsigned char reg)
{
    unsigned char temp;
    CS=lo;
    SSPBUF=((reg&0x3F)<<1); // send register affress to the accelerometer with read command
    while(!SSPSTATbits.BF); // wait for transmit to finish
    temp=SSPBUF;            // reading SSPBUF clears the BF bit
    while(!SSPSTATbits.BF); // wait for receive to finish
    temp=SSPBUF;            // reading SSPBUF clears the BF bit
    CS=hi;                  // pull the CS high to stop transmission
    return temp;
}

//SPI read function (send read register commands to the accelerometer and output resultant read byte)
unsigned char spi_r(unsigned char reg)
{
	unsigned char temp;
	CS = lo; // pull the CS low to start transmission
	SSPBUF=((reg&0x3F)<<1); // // send register address to the accelerometer with read command
	while(!SSPIF);// wait for transmit to finish
	temp=SSPBUF; // reading SSPBUF clears the BF bit
	while(!SSPIF); // wait for receive to finish
	temp=SSPBUF; // reading SSPBUF clears the BF bit
	CS = hi; // pull the CS high to stop transmission
	return temp;

}

void init_ports()
{	ANSEL=0;
	ANSELH=0;
	//Ports Direction:	 "1" inputs and "0" outputs
	TRISA=0b11111000;  //config portA   
	TRISB=0b11110111;  //config portB  RB3=0 (CS SPI)
	TRISC=0b00010000;  //config portC  SCK(RC3)=0, SDI(RC4)=1, SDO(RC5)=0
}

void init_SPI()
{
OpenSPI(FOSC_4,MODE_00,SMPEND); //Mode 00 & SMPEND: CKE=1, CKP=0 & SMP=1
}

//SPI write command function reg
void spi_w(unsigned char regaddr, unsigned char regdata)
{
unsigned char tmp;
CS = lo;	// pull the CS low to start SPI transmission
SSPBUF=(((regaddr&0x3F)<<1)|0x80);	// send register address to the accelerometer with write command
while(!BF);	// wait for transfer
tmp=SSPBUF;	// reading SSPBUF clears the BF bit
SSPBUF=regdata;	// send data into the accelerometer register
while(!BF);
tmp=SSPBUF;	// reading SSPBUF clears the BF bit
CS = hi;	// pull the CS high to stop SPI transmission
}


//SPI read function
unsigned char spi_r(unsigned char reg)
{
unsigned char temp;
CS=lo;
SSPBUF=((reg&0x3F)<<1);	// send register address to the accelerometer with read command
while(!BF);		// wait for transmit to finish
SSPBUF = 0x00;		// reading SSPBUF clears the BF bit
while(!BF);		// wait for receive to finish
temp=SSPBUF;		// reading SSPBUF clears the BF bit
CS=hi;			// pull the CS high to stop transmission
return temp;
}

#include <p18f4550.h>
#include <delays.h>

#pragma config FOSC = HS // use High Speed crystal (20MHz) - not using PLL right now
#pragma config CPUDIV = OSC4_PLL6 // Set speed for 5MHz (divide crystal speed by 4, PLL by 6)
#pragma config PWRT = ON //Power up timer is ON
#pragma config WDT = OFF // Watchdog timer is OFF
#pragma config LVP = ON // Low Voltage Programming ON
#pragma config BOR = OFF //Brown out reset is OFF
#pragma config DEBUG = ON //Debug is ON
#pragma config VREGEN = OFF //Internal voltage regulator is off (not using USB yet)

#define CS LATDbits.LATD0 //Chip Select Latch
#define SCL LATCbits.LATC0 //Clock Latch
#define SDO LATCbits.LATC1 //Data Out Latch
#define SDI PORTCbits.RC2 //Data In Port

#define CST TRISDbits.TRISD0 //Chip Select TRIS
#define SCLT TRISCbits.TRISC0 //Clock TRIS
#define SDOT TRISCbits.TRISC1 //Data Out TRIS
#define SDIT TRISCbits.TRISC2 //Data In TRIS


unsigned char val=0;

void main(void);
void initSPI(void);
unsigned char ReadSPI(unsigned char address);
void WriteSPI(unsigned char address, unsigned char data);
unsigned char SPI_RByte(void);
void SPI_WByte(unsigned char data);


void main (void)
{

 // Make bit 7 the Port D (LED) output bit.
 TRISDbits.TRISD7 = 0;

 //SPI init
 initSPI();

while (1) {
	val=0;// reset value
	LATDbits.LATD7 = 0;// turn LED OFF
	//Set up MMA7455L operation mode by writing to hex addr 16, hex value 05 (2g, 4 wires)
	WriteSPI(0x16,0x05);
	val = ReadSPI(0x16); // read value back from register and if expected value turn ON the LED
	if(val==0x05){LATDbits.LATD7 = 1;Delay10KTCYx(200);}// turn LED ON
	else if(val!=0x05) {LATDbits.LATD7 = 0;}// turn LED ON
			};


}// End of the main program


void initSPI(void){
	SCLT = 0; //Set the SCL (CLOCK) pin to output
	SDOT = 0; //Set the SDO (DATA OUT) pin to output
	SDIT = 1; //Set the SDI (DATA IN) pin to input
	CST = 0; //Set the CS (Chip Select) pin to output
	CS = 0; //Set Chip Select Low
	SDO = 0; //Set Serial Data Out Low
	SCL = 0; //Set Serial Clock Low
}

void SPI_WByte(unsigned char data){
char x;
	for(x=0;x<8;x++){ //Loop 8 bits
		SCL = 0; //Clock Low
		SDO = 0; //Data Low
		if((data & 0x80) != 0) //Clear entire byte except bit 7 and check if byte is greater than 0
			SDO = 1; //Set the Data Out to HIGH
			Delay10TCY(); //Delay 5uS
			SCL = 1; //Clock High
			Delay10TCY(); //Delay 5uS
			data <<= 1; //Shift data bit out to the right
	}
}

unsigned char SPI_RByte(void){
char x,data;
	for(x=0;x<8;x++){ //Loop 8 bits
		SCL = 0; //Clock Low
		Delay10TCY(); //5uS delay
		data <<= 1; //Shift 1 bit to the left
		data &= 0xFE; //Clear BIT 0 from byte without touching the rest
		if(SDI) //if the Serial Data In is HIGH do below if not then leave it 0
			data |= 1; //OR in a 1 into out byte
			Delay10TCY(); //delay 5uS
			SCL = 1; //Clock High
	}
	return data; //return our data
}

void WriteSPI(unsigned char address, unsigned char data){
	SCL = 1; //Clock High
	CS = 0; //Chip Select Low
	address=(((address&0x3F)<<1)|0x80);
	SPI_WByte(address); //Write our address
	SPI_WByte(data); //Write our data
	CS = 1; //Chip Select High
}

unsigned char ReadSPI(unsigned char address){
unsigned char tmp;
	SCL = 1; //Clock High
	CS = 0; //Chip Select Low
	address=((address<<1)&0x7f);// Send read command together with reg address
	SPI_WByte(address); //Write our address to read from
	tmp = SPI_RByte(); //Get the byte from the device
	CS = 1; //Chip Select High
	return tmp; //Return tmp
}