root / trunk / code / projects / libdragonfly / eeprom.c @ 1461
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| 1 | 1461 | bneuman | /**
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| 2 | * @file eeprom.c
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| 3 | * @brief handles eeprom storage for persistent data
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| 4 | *
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| 5 | * Contains functions and definitions for reading and writing to eeprom
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| 6 | *
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| 7 | * @author Colony Project, Brad Neuman
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| 8 | */
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| 9 | |||
| 10 | 853 | bneuman | #include <avr/io.h> |
| 11 | #include "eeprom.h" |
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| 12 | |||
| 13 | 1461 | bneuman | /** @brief store a byte to eeproem
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| 14 | * @return 0 if success, nonzero on failure
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| 15 | */
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| 16 | 853 | bneuman | int eeprom_put_byte(unsigned int uiAddress, unsigned char ucData) { |
| 17 | /* Wait for completion of previous write */
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| 18 | while(EECR & (1<<EEWE)); |
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| 19 | /* Set up address and data registers */
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| 20 | EEAR = uiAddress; |
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| 21 | EEDR = ucData; |
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| 22 | /* Write logical one to EEMWE */
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| 23 | EECR |= (1<<EEMWE);
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| 24 | /* Start eeprom write by setting EEWE */
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| 25 | EECR |= (1<<EEWE);
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| 26 | |||
| 27 | return 0; |
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| 28 | } |
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| 29 | |||
| 30 | 1461 | bneuman | /** @brief reads a byte from eeprom
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| 31 | *
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| 32 | * Pass it thge address and a pointer to a byte where the byte at the
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| 33 | * address will be stored
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| 34 | *
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| 35 | * @return 0 if successful (byte is set to the eeprom value at addr),
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| 36 | * nonzero if there was a problem
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| 37 | */
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| 38 | 853 | bneuman | int eeprom_get_byte(unsigned int uiAddress, unsigned char *byte) { |
| 39 | /* Wait for completion of previous write */
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| 40 | while(EECR & (1<<EEWE)); |
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| 41 | /* Set up address register */
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| 42 | EEAR = uiAddress; |
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| 43 | /* Start eeprom read by writing EERE */
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| 44 | EECR |= (1<<EERE);
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| 45 | /* get data from data register */
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| 46 | *byte=EEDR; |
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| 47 | |||
| 48 | return 0; |
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| 49 | } |
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| 50 | |||
| 51 | 1461 | bneuman | /** @brief get stored robot ID
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| 52 | *
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| 53 | * checks that EEPROM has been programed with an ID and returns it
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| 54 | *
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| 55 | * @return the robot id, if it is stored. If it returns 0xFF it is probably invalid
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| 56 | */
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| 57 | 853 | bneuman | unsigned char get_robotid(void) { |
| 58 | 945 | abuchan | unsigned char c0, c1, c2; |
| 59 | 853 | bneuman | |
| 60 | 945 | abuchan | eeprom_get_byte(EEPROM_ROBOT_ID_ADDR, &c0); |
| 61 | eeprom_get_byte(EEPROM_ROBOT_ID_ADDR+1, &c1);
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| 62 | eeprom_get_byte(EEPROM_ROBOT_ID_ADDR+2, &c2);
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| 63 | if(c0 == 'I' && c1 == 'D') |
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| 64 | return c2;
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| 65 | else
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| 66 | return 0xFF; |
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| 67 | } |
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| 68 | |||
| 69 | 1461 | bneuman | /** @brief get stored robot ID
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| 70 | *
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| 71 | * checks that EEPROM has been programed with an BOM type and returns it
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| 72 | *
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| 73 | * @return the robot bom type as defined in bom.h, if it is stored. If it returns 0xFF it is probably invalid
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| 74 | */
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| 75 | 945 | abuchan | unsigned char get_bom_type(void) { |
| 76 | unsigned char c0, c1, c2, c3; |
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| 77 | 853 | bneuman | |
| 78 | 945 | abuchan | eeprom_get_byte(EEPROM_BOM_TYPE_ADDR, &c0); |
| 79 | eeprom_get_byte(EEPROM_BOM_TYPE_ADDR+1, &c1);
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| 80 | eeprom_get_byte(EEPROM_BOM_TYPE_ADDR+2, &c2);
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| 81 | eeprom_get_byte(EEPROM_BOM_TYPE_ADDR+3, &c3);
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| 82 | if(c0 == 'B' && c1 == 'O' && c2 == 'M') |
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| 83 | return c3;
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| 84 | else
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| 85 | return 0xFF; |
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| 86 | } |