#AP NEW I2C EEPROM Interfacing with LPC2148 (Two Files)

// Save this file as main.c

#include "LPC214x.h"
//#include "UART.h"
#include "stdio.h"

#define EEPROM_Addr 0xA0   //device address
#define I2Cwrite 0x00 //LSB bit 0 (write)
#define I2Cread 0x01 //LSB bit 1 (read)

#define I2C_ENABLE 1 << 6    //I2C Enable bit
#define I2C_START 1 << 5    //Start Bit
#define I2C_STOP 1 << 4    //Stop Bit
#define I2C_SI 1 << 3    //I2C interrupt flag
#define I2C_AACK  1 << 2    //assert ACK flag

unsigned char write_array[10] = {0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0xC5};
unsigned char read_array[10];


void I2CInit(void)
{
PINSEL0 &= 0xFFFFFF0F; //set the pins for i2c functions
PINSEL0 |= 0x00000050; //P0.2 -> SCL0 P0.3 -> SDA0

I2C0CONCLR  = I2C_ENABLE | I2C_START | I2C_STOP | I2C_SI | I2C_AACK; //clear all the bits in CONTROL register

//set I2C clock to work at 100Khz
I2C0SCLH = 0x4B ; //set the high time of i2c clock; (15mhz / 100khz / 2)
I2C0SCLL = 0x4B ; //set the low time of i2c clock;

I2C0CONSET = I2C_ENABLE ; //enable the I2C Interface
}


void I2CStart(void)   //Function to initiate a start condition on the I2C bus
{
unsigned int status;
I2C0CONCLR = (I2C_START | I2C_STOP | I2C_SI | I2C_AACK); // clear all the bits in CONCLR register
I2C0CONSET = (I2C_ENABLE );   //Enable the I2C interface
I2C0CONSET = (I2C_START);   //set the STA bit
while(!((status=I2C0CONSET)& I2C_SI)); //wait till interrupt flag becomes set
}


void I2CStop(void)
{
unsigned int status;
I2C0CONCLR = I2C_START | I2C_SI | I2C_AACK; //clear all bits
I2C0CONSET = I2C_STOP; //set STOP bit
}


void I2Csend(unsigned char data)
{  
unsigned int status;
I2C0DAT = data;
I2C0CONCLR = I2C_START | I2C_STOP ; // clear start bit for next operation
I2C0CONCLR = I2C_SI; // clear interrupt flag
while(!((status=I2C0CONSET)& I2C_SI));     //wait till interrupt flag becomes set
}

unsigned char I2Cget(void)
{
unsigned char data;
unsigned int status;

I2C0CONCLR = I2C_START | I2C_STOP;
I2C0CONCLR = I2C_SI; // clear interrupt flag
I2C0CONSET = I2C_AACK;     // send ack to continue further data transfer
while(!((status=I2C0CONSET)& I2C_SI)); //wait till interrupt flag becomes set
data = I2C0DAT;
return data;
}


int main()
{
unsigned int i;
UartInit(9600);   //initialize UART with 9600 baudrate
printf("\nI2C EEPROM\n\n");
I2CInit();   //initialize I2C


  /* Write Sequence */
printf("Writing Data.....\n");
I2CStart(); //Assert START
I2Csend(EEPROM_Addr | I2Cwrite); //Device address with LSB bit 0
I2Csend(0x13);     //Address higher byte
I2Csend(0x49); //Address lower byte
for(i=0;i<10;i++)
I2Csend(write_array[i]); //write the array to EEPROM
I2CStop(); //Assert STOP


/* Read Sequence */
printf("\nReading.....\n\n");
I2CStart(); //Assert START
I2Csend(EEPROM_Addr | I2Cwrite); //Device address with LSB bit 0 (Dummy Write)
I2Csend(0x13); //Address higher byte
I2Csend(0x49); //Address lower byte
I2CStart(); //Assert Restart
I2Csend(EEPROM_Addr | I2Cread); //Device address with LSB bit 1
for(i=0;i<10;i++)
read_array[i] = I2Cget(); //Read EEPROM
I2CStop(); //Assert STOP


/*Display Write and Read Data*/
for(i=0;i<10;i++)
printf("write_array[%d] = 0x%02X\tread_array[%d] = 0x%02X\n", i, write_array[i], i, read_array[i]);   //display write and read data


while(1); //stop here forever
return 0;
}





/********************************************************************
// Save this file as UART.c

#include "stdio.h"
#include "LPC214x.h"

void UartInit(unsigned int);
int UART_GetChar(void);
int UART_PutChar(unsigned char);

void UartInit(unsigned int baudrate)
{
unsigned int FDiv;
PINSEL0 &= 0xFFFFFFF0; //configure RX0 and TX0 pins
PINSEL0 |= 0x00000005;
U0LCR = 0x83;
U0FDR = 0x10; // Line control register :DLAB=1 ; 8 bits ; 1 stop bit ; no parity
FDiv = (15000000 / 16 ) / baudrate ; //
U0DLM = FDiv /256; //0x00;
U0DLL = FDiv %256; //0x97;
U0LCR = 0x03; // Line control register :DLAB=0 ; 8 bits ; 1 stop bit ; no parity
U0TER = 0x80;
}


int UART_GetChar(void)
{
while(!(U0LSR & 0x1));
return(U0RBR);
}

int UART_PutChar(unsigned char Ch)
{
 if (Ch == '\n')  {
    while (!(U0LSR & 0x20));
    U0THR = 0x0D;                          /* output CR */
}

  while(!(U0LSR & 0x20));
return( U0THR = Ch);
}


int fputc(int ch, FILE *f) {
  return (UART_PutChar(ch));
}

struct __FILE { int handle; /* Add whatever you need here */ };
FILE __stdout;