Colony

/**

 * @file eeprom.c

 * @brief handles eeprom storage for persistent data

 *

 * Contains functions and definitions for reading and writing to eeprom

 *

 * @author Colony Project, Brad Neuman

 */

#include <avr/io.h>

#include "eeprom.h"

/** @brief store a byte to eeproem

 *  @return 0 if success, nonzero on failure

 */

int eeprom_put_byte(unsigned int uiAddress, unsigned char ucData) {

    /* Wait for completion of previous write */

    while(EECR & (1<<EEWE));

    /* Set up address and data registers */

    EEAR = uiAddress;

    EEDR = ucData;

    /* Write logical one to EEMWE */

    EECR |= (1<<EEMWE);

    /* Start eeprom write by setting EEWE */

    EECR |= (1<<EEWE);

    return 0;

}

/** @brief reads a byte from eeprom

 *

 *  Pass it thge address and a pointer to a byte where the byte at the

 *  address will be stored

 *

 *  @return 0 if successful (byte is set to the eeprom value at addr), 

 *  nonzero if there was a problem

 */

int eeprom_get_byte(unsigned int uiAddress, unsigned char *byte) {

    /* Wait for completion of previous write */

    while(EECR & (1<<EEWE));

    /* Set up address register */

    EEAR = uiAddress;

    /* Start eeprom read by writing EERE */

    EECR |= (1<<EERE);

    /* get data from data register */

    *byte=EEDR;

    return 0;

}

/** @brief get stored robot ID

 *

 *  checks that EEPROM has been programed with an ID and returns it

 *

 *  @return the robot id, if it is stored. If it returns 0xFF it is probably invalid

 */

unsigned char get_robotid(void) {

    unsigned char c0, c1, c2;

    eeprom_get_byte(EEPROM_ROBOT_ID_ADDR, &c0);

    eeprom_get_byte(EEPROM_ROBOT_ID_ADDR+1, &c1);

    eeprom_get_byte(EEPROM_ROBOT_ID_ADDR+2, &c2);

    if(c0 == 'I' && c1 == 'D')

        return c2;

    else

        return 0xFF;

}

/** @brief get stored robot ID

 *

 * checks that EEPROM has been programed with an BOM type and returns it

 *

 *  @return the robot bom type as defined in bom.h, if it is stored. If it returns 0xFF it is probably invalid

 */

unsigned char get_bom_type(void) {

    unsigned char c0, c1, c2, c3;

    eeprom_get_byte(EEPROM_BOM_TYPE_ADDR, &c0);

    eeprom_get_byte(EEPROM_BOM_TYPE_ADDR+1, &c1);

    eeprom_get_byte(EEPROM_BOM_TYPE_ADDR+2, &c2);

    eeprom_get_byte(EEPROM_BOM_TYPE_ADDR+3, &c3);

    if(c0 == 'B' && c1 == 'O' && c2 == 'M')

        return c3;

    else

        return 0xFF;

}