okaay, da sich hier scheinbar alle kategorisch weigern mir mit GCC weiterzuhelfen probier ichs nochmal:

Code:
#include <avr/io.h>

#include "i2cmaster.h"

#define POWER_PORTS_I2C  0x72

int main(void) {
	i2c_init();                                	
	uint8_t ret;
	ret = i2c_start(POWER_PORTS_I2C + I2C_WRITE);
	if ( ret ) {

        	i2c_stop();
	} else {
		uint8_t value;
		value = 1;
		while(1) {
			i2c_start_wait(POWER_PORTS_I2C + I2C_WRITE); 
			i2c_write(value);
			i2c_stop();
			value = value * 2;
			if(value > 16) {
				value = 1;
			}
		}
	}
}
Warum kann der Code nicht compilieren?

mathias@mathias-laptop:~/Desktop/avr.programing/avr-gcc/mytest$ make

-------- begin --------
avr-gcc (GCC) 4.1.0
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


Linking: LED_Test.elf
avr-gcc -mmcu=atmega32 -I. -gstabs -DF_CPU=8000000UL -Os -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall -Wstrict-prototypes -Wa,-adhlns=LED_Test.o -std=gnu99 -Wundef -MMD -MP -MF .dep/LED_Test.elf.d LED_Test.o --output LED_Test.elf -Wl,-Map=LED_Test.map,--cref -lm
LED_Test.o: In function `main':
LED_Test.c:15: undefined reference to `i2c_init'
LED_Test.c:17: undefined reference to `i2c_start'
LED_Test.c:25: undefined reference to `i2c_start_wait'
LED_Test.c:26: undefined reference to `i2c_write'
LED_Test.c:27: undefined reference to `i2c_stop'
LED_Test.c:25: undefined reference to `i2c_start_wait'
LED_Test.c:26: undefined reference to `i2c_write'
LED_Test.c:27: undefined reference to `i2c_stop'
LED_Test.c:25: undefined reference to `i2c_start_wait'
LED_Test.c:26: undefined reference to `i2c_write'
LED_Test.c:27: undefined reference to `i2c_stop'
LED_Test.c:25: undefined reference to `i2c_start_wait'
LED_Test.c:26: undefined reference to `i2c_write'
LED_Test.c:27: undefined reference to `i2c_stop'
LED_Test.c:19: undefined reference to `i2c_stop'
make: *** [LED_Test.elf] Fehler 1
Woran liegt das? Die Methoden liegen in i2cmaster.h, was ja auch included ist.