RE: [avr-gcc-list] AVR eeprom

[Ron Kreymborg]

> Hi all,
>
> Is it possible to write to the eeprom with the avr-gcc tools?  Is
> this done
> automatically for static variables in the code?  Any on chip eeprom
> write/read routines floating around in hyperspace are welcome in this
> quadrant! :)
>
> best regards,
> Jamie Morken

Here are some functions I use. You can see what the additional functions
would be for ints, chars, etc.

Regards, Ron

============================================================================
========
#include <eeprom.h>

// An example eeprom variable definition. Use type specifiers to define
// various other types (int, char, etc).
//
float eSomeVariableName __attribute__((section(".eeprom"))) = 10.0; //
initial value

//--------------------------------------------------------------------------
---
// Write a 4-byte float to the specified eeprom address.
//
void eWriteFloat(float *numPtr, void *addr)
{
    BYTE *ptr, *num;

    ptr = (BYTE*)addr;
    num = (BYTE*)numPtr;
    eeprom_wb((int)ptr++, *num++);        // use gcc AVR extension
    eeprom_wb((int)ptr++, *num++);
    eeprom_wb((int)ptr++, *num++);
    eeprom_wb((int)ptr++, *num++);
}

//--------------------------------------------------------------------------
---
// Read a 4-byte float from the specified address.
//
float eFloat(float *ptr)
{
    float a;

    eeprom_read_block(&a, (int)ptr, 4);   // use gcc AVR extension
    return a;
}


    // An example of accessing an eeprom variable:
    float localFloat;

    localFloat = 23.4 + eFloat(&eSomeVariableName);

============================================================================
========