//************************************************************
// I2C_EEPROM Check(CPU: dsPIC30F4013)
//
// Soft I2C
// Used AT24C256
//
// LCD unlook busy : not switch direction (write fixed)
//
// CPU dsPIC30F4013
// 7.37MHz Internal RC oscillator, 16x PLL enabled
// Fcy=7.37MHzx16/4=29.48MHz, Tcy=33.92ns
//
// 2010/9/11: N.Ishii
//*************************************************************

#include <p30f4013.h>

// Divice configuration
_FWDT(WDT_OFF);
_FGS(CODE_PROT_OFF);
_FOSC(CSW_FSCM_OFF & FRC_PLL16);	//OSC, PLL Setting
_FBORPOR(PBOR_OFF & PWRT_64 & MCLR_EN);


// LCD Define: R/W_pin= GND (Fixed Write)
#define LCD_DATA_WR_MODE LATFbits.LATF1 = 1	// RS_pin = 1
#define LCD_INST_WR_MODE LATFbits.LATF1 = 0	// RS_pin = 0

#define LCD_ENABLE_ON LATFbits.LATF0 = 1
#define LCD_ENABLE_OFF LATFbits.LATF0 = 0


#define LCD_DATA_BIT4 LATBbits.LATB9
#define LCD_DATA_BIT5 LATBbits.LATB10
#define LCD_DATA_BIT6 LATBbits.LATB11
#define LCD_DATA_BIT7 LATBbits.LATB12

//---------------------------------------------------------------------------------------------
// LCD Instraction Code
#define FOUR_BIT_FONT5x7dot 0x28	// + TWO_LINE(1/16Duty), SEG1_50_SEG51_100, COM1_COM16
#define DISP_ON_CURSOR_ON_BLINK_OFF 0x0e
#define DISP_CLEAR_CURSOR_HOME 0x01
#define RAM_WR_AFTER_PLUS_1 0x06	// Entory mode set
#define DDRAM_START_ADDRESS_SET 0x80

#define DISP_ON_CURSOR_OFF_BLINK_OFF 0x0c

//---------------------------------------------------------------------------------------------
//  I2C define
#define EEPROM_SLVADRS_WR 0xa0
#define EEPROM_SLVADRS_RD 0xa1

#define SDA_OUT  LATFbits.LATF2
#define SCL_OUT  LATFbits.LATF3

#define SDA_IN  PORTFbits.RF2


//---------------------------------------------------------------------------------------------
// For I2C
unsigned char test_data[] = {0x55,0xaa};	// For TEST Data Table: 0x55-> 085Dec, 0xaa-> 170Dec
unsigned char rec_data[16];

//-------------------------------------------------------------------------
// Delay Subrutin
void Waitx1ms(int x)	// Td = 1mS * x
{
	int i,j;

	for(i = 0 ; i < x ; ++i) {
		for(j = 0 ; j < 5000 ; ++j) asm("clrwdt");	//Td=1mS
	}
}


void Waitx1us(int x)	// Td = 1uS * x
{
	int i,j;

	for(i = 0 ; i < x ; ++i) {
		for(j = 0 ; j < 5 ; ++j) asm("clrwdt");	//Td=1uS
	}
}

//--------------------------------------------------------------------

void one_chr_wr(char chr_code)
{
	LCD_DATA_WR_MODE;	//RS_pin = 1: select data Reg

	// A Higher 4bit data out
	LCD_DATA_BIT7 = (unsigned int)((chr_code & 0x80)>>7);
	LCD_DATA_BIT6 = (unsigned int)((chr_code & 0x40)>>6);
 	LCD_DATA_BIT5 = (unsigned int)((chr_code & 0x20)>>5);
 	LCD_DATA_BIT4 = (unsigned int)((chr_code & 0x10)>>4);

	Waitx1us(1);
	LCD_ENABLE_ON;
	Waitx1us(1);
	LCD_ENABLE_OFF;

	// A Lower 4bit data out
	LCD_DATA_BIT7 = (unsigned int)((chr_code & 0x08)>>3);
   	LCD_DATA_BIT6 = (unsigned int)((chr_code & 0x04)>>2);
   	LCD_DATA_BIT5 = (unsigned int)((chr_code & 0x02)>>1);
   	LCD_DATA_BIT4 = (unsigned int)(chr_code & 0x01);

	Waitx1us(1);
	LCD_ENABLE_ON;
	Waitx1us(1);
	LCD_ENABLE_OFF;

	Waitx1us(50);
}

void lcd_chr_wr(char *buffer)
{
    while(*buffer != '\0')
    {
        one_chr_wr(*buffer); /* calling another function */
                                /* to write each char to the lcd module */
        buffer++;
    }
}

void lcd_inst_wr(char inst_code)
{
	LCD_INST_WR_MODE;	//RS_pin = 0: select Instruction Reg
	
	// A Higher 4bit data out
	LCD_DATA_BIT7 = (unsigned int)((inst_code & 0x80)>>7);
  	LCD_DATA_BIT6 = (unsigned int)((inst_code & 0x40)>>6);
  	LCD_DATA_BIT5 = (unsigned int)((inst_code & 0x20)>>5);
   	LCD_DATA_BIT4 = (unsigned int)((inst_code & 0x10)>>4);

	Waitx1us(1);
	LCD_ENABLE_ON;
	Waitx1us(1);
	LCD_ENABLE_OFF;

	// A Lower 4bit data out
	LCD_DATA_BIT7 = (unsigned int)((inst_code & 0x08)>>3);
   	LCD_DATA_BIT6 = (unsigned int)((inst_code & 0x04)>>2);
  	LCD_DATA_BIT5 = (unsigned int)((inst_code & 0x02)>>1);
  	LCD_DATA_BIT4 = (unsigned int)(inst_code & 0x01);

	Waitx1us(1);
	LCD_ENABLE_ON;
	Waitx1us(1);
	LCD_ENABLE_OFF;
	
	if ((inst_code & 0x03) != 0) Waitx1ms(20);	// inst_code is Clear(0x01) or Cursor Home(0x02) Then Wait 20mS
		else Waitx1us(50);			// other code Then Wait 50uS  
}

void lcd_init(void)
{
	// Allow a delay(minimum of 15ms)
	Waitx1ms(20);

//------ 1st step: port_output regster set --------------

	// Initialize the data port/control pins to zero
 	LCD_DATA_BIT7 = 0;
 	LCD_DATA_BIT6 = 0;
 	LCD_DATA_BIT5 = 0;
 	LCD_DATA_BIT4 = 0;

	LCD_INST_WR_MODE;	//RS_pin = 0
	LCD_ENABLE_OFF;		//E_pin  = 0
	
//--------------------------------------------------------

// dsPIC30F4013

//------- 2nd step: port_mode regster set ---------------

	// Configure the data pins as output

	TRISBbits.TRISB9 =0;  // RB9  is LCD DB4 OUTPUT
	TRISBbits.TRISB10 =0;  // RB10 is LCD DB5 OUTPUT
	TRISBbits.TRISB11 =0;  // RB11  is LCD DB6 OUTPUT
	TRISBbits.TRISB12 =0;  // RB12  is LCD DB7 OUTPUT

	// Make all control pins as outputs
	TRISFbits.TRISF0 =0;  // RF0 is LCD Enable OUTPUT
	TRISFbits.TRISF1 =0;  // RF1  is LCD RS OUTPUT

//-------------------------------------------------------


 	// Initialize stage 1: Set stage 1 only 8-bit Interface

	// Set Upper 4 Bit Data on RB9 - RB12
 	LCD_DATA_BIT7 = 0;
 	LCD_DATA_BIT6 = 0;
 	LCD_DATA_BIT5 = 1;
 	LCD_DATA_BIT4 = 1;

	Waitx1us(1);
	LCD_ENABLE_ON;
	Waitx1us(1);
	LCD_ENABLE_OFF;

	Waitx1ms(5);	

 	// Initialize stage 2: Set stage 2 only 8-bit Interface
 	LCD_DATA_BIT7 = 0;
 	LCD_DATA_BIT6 = 0;
 	LCD_DATA_BIT5 = 1;
 	LCD_DATA_BIT4 = 1;

	Waitx1us(1);
	LCD_ENABLE_ON;
	Waitx1us(1);
	LCD_ENABLE_OFF;

	Waitx1ms(1);	

 	// Initialize stage 3: Set stage 3 only 8-bit Interface
 	LCD_DATA_BIT7 = 0;
 	LCD_DATA_BIT6 = 0;
 	LCD_DATA_BIT5 = 1;
 	LCD_DATA_BIT4 = 1;

	Waitx1us(1);
	LCD_ENABLE_ON;
	Waitx1us(1);
	LCD_ENABLE_OFF;

	Waitx1ms(1);	

	// Initialize stage 4: 4-bit Interface
 	LCD_DATA_BIT7 = 0;
 	LCD_DATA_BIT6 = 0;
 	LCD_DATA_BIT5 = 1;
 	LCD_DATA_BIT4 = 0;
	
	Waitx1us(1);
	LCD_ENABLE_ON;
	Waitx1us(1);
	LCD_ENABLE_OFF;

	Waitx1ms(1);	

	//----- Fixed LCD Setting------------

	lcd_inst_wr(FOUR_BIT_FONT5x7dot);	// Function Set
	lcd_inst_wr(DISP_ON_CURSOR_ON_BLINK_OFF);
	lcd_inst_wr(DISP_CLEAR_CURSOR_HOME);	// Set DDRAM Address = 0
	lcd_inst_wr(RAM_WR_AFTER_PLUS_1);	// Entry mode Set
}

//-------------------------------------------------------------------------

void variable_disp(unsigned char Vol, unsigned char loc)
{
	// Vol: 0x00-0xff( 000-255 Disp)

	unsigned char i;
	unsigned char digit[3];
	unsigned char ascii[3];

	// Bin_to_pacdec
	digit[0] = Vol%10;
	digit[1] = (Vol/10)%10;
	digit[2] = (Vol/100)%10;
/*
	digit[3] = (Vol/100)/10;
*/

	// Decimal_to_ascii
	for (i = 0; i <= 2; ++i) {ascii[i] = digit[i] | 0x30;}

	// LCD Disp
	lcd_inst_wr(loc);
	one_chr_wr(ascii[2]);
	one_chr_wr(ascii[1]);
	one_chr_wr(ascii[0]);
}


//------------------------------------------------------------------------------
// Soft I2C Sub routine

void i2c_write(unsigned char send_data)
{

	unsigned char i;

	for (i = 0; i <= 7; ++i) {
		if  (( send_data & 0x80) == 0)  SDA_OUT = 0;
			else SDA_OUT = 1;

		Waitx1us(5);
		SCL_OUT = 1;
		Waitx1us(5);
		SCL_OUT = 0;

		send_data <<= 1;
	}
}

unsigned char i2c_read(void)
{
	unsigned char i;
	unsigned char read_data;

	TRISFbits.TRISF2=1; // RF2 is SDA Input

	for (i = 0; i <= 7; ++i) {
		read_data <<= 1;
		read_data |= SDA_IN;

		Waitx1us(5);
		SCL_OUT = 1;
		Waitx1us(5);
		SCL_OUT = 0;

	}

	return(read_data);
}

void receive_ack(void)
{
	TRISFbits.TRISF2=1; // RF2 is SDA Hi-Z(input)

	Waitx1us(5);
	SCL_OUT = 1;

	while(SDA_IN != 0);  // Wait ACK

	Waitx1us(5);
	SCL_OUT = 0;
 
	TRISFbits.TRISF2=0; // RF2 is SDA output
}

//------------------------------------------------------------------------------------
void i2c_write_sr(unsigned int start_adrs, unsigned char len)
{
	// start_adrs: 0x0000min - 0x7fffmax (EEPROM: 32768Bytes)

	unsigned char low_temp;
	unsigned char high_temp;

	low_temp = (char)(start_adrs & 0x00ff);
	high_temp = (char)((start_adrs >> 8) & 0x00ff);

	unsigned char i;


	// START Bus Event
	TRISFbits.TRISF3=0; // RF3 is SCL output
	TRISFbits.TRISF2=0; // RF2 is SDA output

	SCL_OUT = 1;
	SDA_OUT = 1;
	Waitx1us(5);
	SDA_OUT = 0;
	Waitx1us(5);
	SCL_OUT = 0;		

	// Send Slave Address + Writebit
	i2c_write(EEPROM_SLVADRS_WR);

	// Receive ACK From EEPROM
	receive_ack();

	
	// Send Write Top High Address
	Waitx1us(40);
	i2c_write(high_temp);

	// Receive ACK From EEPROM
	receive_ack();

	// Send Write Top Low Address
	Waitx1us(40);
	i2c_write(low_temp);

	// Receive ACK From EEPROM
	receive_ack();


	// Send EEPROM Write Data (Write Address Auto Incriment)
	for (i = 0; i != len; ++i) {
		Waitx1us(40);
		i2c_write(test_data[i]);

		// Receive ACK From RTC8564
		receive_ack();
	}

	// Stop Bus Event
	SDA_OUT = 0;
	Waitx1us(5);
	SCL_OUT = 1;
	Waitx1us(5);
	SDA_OUT = 1;

	TRISFbits.TRISF3=1; // RF3 is SCL Hi-Z
	TRISFbits.TRISF2=1; // RF2 is SDA Hi-Z

	Waitx1ms(10);

}

void i2c_read_sr(unsigned int start_adrs, unsigned char len)
{
	unsigned char low_temp;
	unsigned char high_temp;

	low_temp = (char)(start_adrs & 0x00ff);
	high_temp = (char)((start_adrs >> 8) & 0x00ff);

	unsigned char i;

	// START Bus Event
	TRISFbits.TRISF3=0; // RF3 is SCL output
	TRISFbits.TRISF2=0; // RF2 is SDA output

	SCL_OUT = 1;
	SDA_OUT = 1;
	Waitx1us(5);
	SDA_OUT = 0;
	Waitx1us(5);
	SCL_OUT = 0;

	// Send Slave Address + Writebit
	i2c_write(EEPROM_SLVADRS_WR);

	// Receive ACK From EEPROM
	receive_ack();

	// Send Read Start High Address
	Waitx1us(40);
	i2c_write(high_temp);

	// Receive ACK From EEPROM
	receive_ack();

	// Send Read Start Low Address
	Waitx1us(40);
	i2c_write(low_temp);

	// Receive ACK From EEPROM
	receive_ack();

	// RESTART Bus Event
	Waitx1us(40);

	SDA_OUT = 1;
	Waitx1us(5);
	SCL_OUT = 1;
 
	Waitx1us(5);
	SDA_OUT = 0;
	Waitx1us(5);
	SCL_OUT = 0;

	// Send Slave Address + Readbit
	i2c_write(EEPROM_SLVADRS_RD);

	// Receive ACK From EEPROM
	receive_ack();

	// Receive EEPROM Read Data (Read Address Auto Incriment)
	for (i = 0; i != len; ++i) {
		Waitx1us(40);
		rec_data[i] = i2c_read();

		// Send ACK From PIC
		if (i != len - 1) {
			TRISFbits.TRISF2=0; // RF2 is SDA output

			SDA_OUT = 0;
			Waitx1us(5);
			SCL_OUT = 1;
			Waitx1us(5);
			SCL_OUT = 0;
		}
 	} 

	// Send NACK From PIC: End of Rx
	TRISFbits.TRISF2=0; // RF2 is SDA output

	SDA_OUT = 1;
	Waitx1us(5);
	SCL_OUT = 1;
	Waitx1us(5);
	SCL_OUT = 0;

	// Stop Bus Event
	SDA_OUT = 0;
	Waitx1us(5);
	SCL_OUT = 1;
	Waitx1us(5);
	SDA_OUT = 1;

	TRISFbits.TRISF3=1; // RF3 is SCL Hi-Z
	TRISFbits.TRISF2=1; // RF2 is SDA Hi-Z

}

//---------------------------------------------------------------------------------------------

// Main routine
int main(void)
{
	// Set ADPCFG: RB1 Port is All Digital Pin
	ADPCFG = 0xFFFF;

	TRISDbits.TRISD0=0;	// RD0 is LED output used debug
	PORTDbits.RD0 = 1;	// Red LED OFF

 	// Initialize I2C Port
 	TRISFbits.TRISF3=1; // RF3 is SCL Hi-Z
 	TRISFbits.TRISF2=1; // RF2 is SDA Hi-Z

	// Initialize LCD
	lcd_init();
	lcd_inst_wr(DISP_ON_CURSOR_OFF_BLINK_OFF);

	Waitx1ms(10);

	i2c_write_sr(0x1234,2);

	i2c_read_sr(0x1234,2);

	variable_disp(rec_data[0],0x80);
	variable_disp(rec_data[1],0xc0);

	PORTDbits.RD0 = 0;	// Red LED ON


	while(1)
	{
		;	
	}
}