Can't write to eeprom on avr

Development Boards MicroMod
1

Hi can anybody tell me why it doesn’t write to the eeprom.

I know the firmware is executing since the led is turned off if change the following to a 1

PORTC = (0 << BOOTLED_BIT);

I’m using the avr gcc library functions to write to the eeprom

The reason why I think it isn’t working is the led should be switched off when I written a 0 to the eeprom.

In C programming 0 is false and 1 is true. Therefore if I write a 0 and switch isn’t pressed he bootloader shouldn’t execute

and led should be off. I’ve initialise the output to be a high and so the current going to led isn’t being directed to gnd.

I’m using an atmega 328p

/* initialize hardware */

bootLoaderInit();

odDebugInit();

DBG1(0x00, 0, 0);

/* jump to application if jumper is set */

unsigned char do_boot_load;

unsigned char do_boot_load_via_eeprom;

uint8_t addr;

do_boot_load = ~PIND & (1 << JUMPER_BIT); // see if jumper is set (= 0)

do_boot_load_via_eeprom = eeprom_read_byte(addr); // bootloader bit in eeprom address 0

if(do_boot_load || do_boot_load_via_eeprom){

addr=5;

eeprom_write_byte( (uint8_t *)addr, 6) ;

PORTC = (0 << BOOTLED_BIT); // turn bootloader led on

uchar i = 0, j = 0;

#ifndef TEST_MODE

GICR = (1 << IVCE); /* enable change of interrupt vectors */

GICR = (1 << IVSEL); /* move interrupts to boot flash section */

#endif

initForUsbConnectivity();

do{ /* main event loop */

wdt_reset();

usbPoll();

#if BOOTLOADER_CAN_EXIT

if(exitMainloop){

#if F_CPU == 12800000

break; /* memory is tight at 12.8 MHz, save exit delay below */

#endif

if(–i == 0){

if(–j == 0)

break;

}

}

#endif

}while(1);

}

leaveBootloader()

2

amateur_24:
uint8_t addr;

do_boot_load = ~PIND & (1 << JUMPER_BIT); // see if jumper is set (= 0)

do_boot_load_via_eeprom = eeprom_read_byte(addr); // bootloader bit in eeprom address 0

addr is uninitialized here. What address do you actually mean to read?

3

The reason its not writing is because you casted the value of addr to a pointer on this line:

eeprom_write_byte( (uint8_t *)addr, 6) ;

so your giving the function garbage address information.

Change the line to this:

eeprom_write_byte( &addr, 6) ;

and initialize your addr variable as theatrus mentioned.