/*,-----------------------------------------------------------------------------------------.| io/eeprom|-----------------------------------------------------------------------------------------| this file implements functions for reading & writing an 24LCxx I2C EEprom| - BLOCKING !!! BE CAREFULL! || Author   : {{removed according to contest rules}}|            -> circuitcellar.com avr design contest 2006|            -> Entry #AT2616||-----------------------------------------------------------------------------------------| License:| This program is free software; you can redistribute it and/or modify it under| the terms of the GNU General Public License as published by the Free Software| Foundation; either version 2 of the License, or (at your option) any later| version.| This program is distributed in the hope that it will be useful, but|| WITHOUT ANY WARRANTY;|| without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR| PURPOSE. See the GNU General Public License for more details.|| You should have received a copy of the GNU General Public License along with| this program; if not, write to the Free Software Foundation, Inc., 51| Franklin St, Fifth Floor, Boston, MA 02110, USA|| http://www.gnu.de/gpl-ger.html`-----------------------------------------------------------------------------------------*/#include "eeprom.h"#include "main.h"#include <avr/delay.h>#define EEPROM_DEVICE_ID 0xA0#define EEPROM_READ  1#define EEPROM_WRITE 0void eeprom_init(void) {	//initialize TWI clock: 100 kHz clock, TWPS = 0 => prescaler = 1 	#if defined(TWPS0)		//has prescaler (mega128 & newer)		TWSR = 0;	#endif	TWBR = 6;}void eeprom_send_start(){	//start cond.	TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN);	while (!(TWCR & (1 << TWINT)));}void eeprom_send_stop(){	//stop condition	TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);}void eeprom_send_device_address(unsigned char addr){	//send device address (including pge offset + write/read flag)	TWDR = addr;	TWCR = (1 << TWINT) | (1 << TWEN);	while (!(TWCR & (1 << TWINT)));}void eeprom_send_byte(unsigned char byte){	TWDR = byte;	TWCR = (1 << TWINT) | (1 << TWEN);	while (!(TWCR & (1 << TWINT)));}unsigned char eeprom_read(){	//start read transmission	TWCR = (1 << TWINT) | (1 << TWEN);	while (!(TWCR & (1 << TWINT)));	return TWDR;}void eeprom_write(unsigned char data){	//load byte to data reg and start transmission	TWDR = data;	TWCR = (1 << TWINT) | (1 << TWEN);	while (!(TWCR & (1 << TWINT)));}unsigned char eeprom_read_byte(unsigned int addr){	unsigned char res;	unsigned char eeprom_addr;	eeprom_addr = (EEPROM_DEVICE_ID&0xF0) | ((addr>>7)&0x0E);	//send start	eeprom_send_start();	//send device address & page info: (write cmd !)	eeprom_send_device_address(eeprom_addr | EEPROM_WRITE);		//send eeprom word address:	eeprom_send_byte(addr&0xFF);	//send start	eeprom_send_start();	//send device address & page info: (read cmd !)	eeprom_send_device_address(eeprom_addr | EEPROM_READ);		//read data:	res = eeprom_read();	//stop	eeprom_send_stop();	return res;}	void eeprom_wait_for_write_finished(unsigned int addr){	unsigned char eeprom_addr;	eeprom_addr = (EEPROM_DEVICE_ID&0xF0) | ((addr>>7)&0x0E);	//pull write completion flag:	while(1){		eeprom_send_start();		//eeprom_send_device_address(eeprom_addr | EEPROM_WRITE);		TWDR = eeprom_addr | EEPROM_WRITE;		TWCR = (1 << TWINT) | (1 << TWEN);		while (!(TWCR & (1 << TWINT)));				//if we have an ack -> write is finished !		if ((TWSR & 0xF8) == 0x18){			eeprom_send_stop();			return;		}		eeprom_send_stop();	}}void eeprom_write_byte(unsigned int addr, unsigned char buf) {	unsigned char eeprom_addr;	eeprom_addr = (EEPROM_DEVICE_ID&0xF0) | ((addr>>7)&0x0E);		eeprom_wait_for_write_finished(addr);	//send start	eeprom_send_start();	//send device address & page info: (write cmd !)	eeprom_send_device_address(eeprom_addr | EEPROM_WRITE);		//send eeprom word address:	eeprom_send_byte(addr&0xFF);	//write data:	eeprom_write(buf);	//stop	eeprom_send_stop();	}void eeprom_dump(){	unsigned int i;	for(i=0; i<8*255; i++)		uart_putc(eeprom_read_byte(i));	}//erases all data !!!!void eeprom_clear(){	unsigned int i;	for(i=0; i<8*255; i++)		eeprom_write_byte(i, 0x00);	}