Atmega8 TWI Initialisierungsproblem

#ifndef F_CPU

#define F_CPU 16000000UL

#endif

/* I2C clock in Hz */

#define SCL_CLOCK  100000L

/*************************************************************************

 Initialization of the I2C bus interface. Need to be called only once

*************************************************************************/

void i2c_init(void)

{

  /* initialize TWI clock: 100 kHz clock, TWPS = 0 => prescaler = 1 */

  TWSR = 0;                         /* no prescaler */

  TWBR = ((F_CPU/SCL_CLOCK)-16)/8;  /* must be > 10 for stable operation */