STM32F10x mit Atmega8 über i2c funktioniert nicht?

while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); // Here it hangs...

//  STM32 Discovery I2C Sample

#include "stm32f10x.h"

#include "i2c.h"

#define STACK_TOP 0x20002000-4                    // init Stackpointer

void nmi_handler(void);                        

void hardfault_handler(void);

unsigned char temp = 0;

unsigned char temp2 = 0;

int main(void);

/* vector table */

unsigned int * myvectors[4] 

__attribute__ ((section("vectors")))= {

    (unsigned int *)  STACK_TOP,         

    (unsigned int *)   main,              

    (unsigned int *)  nmi_handler,       

    (unsigned int *)  hardfault_handler,

};

int main(void){  

  int SLAVE_ADDR = 0x50;

  /* Enable the GPIOA (bit 2) and GPIOC (bit 8) */

  RCC->APB2ENR |= 0x10 | 0x04;

  /* Set GPIOC Pin 8 and Pin 9 to outputs */

  GPIOC->CRH = 0x11;

  /* Set GPIOA Pin 0 to input floating */

  GPIOA->CRL = 0x04;

  /*

  GPIOC->BSRR = 1<<8;   //Switch on blue

  GPIOC->BSRR = 1<<24;  //Switch off blue

  GPIOC->BSRR = 1<<9 ;  //Switch green on

  GPIOC->BSRR = 1<<25;  //Switch green off

  */

  char buf[20];

  int off = 0;

  int len = 1;

  buf[0] = 'H';

  buf[1] = 'a';

  buf[2] = 'l';

  InitI2C();

  I2C_start(I2C1, SLAVE_ADDR << 1, I2C_Direction_Transmitter);

  I2C_write(I2C1, 0x00);    //Set internal Slave register

  I2C_write(I2C1, buf[0]);

  I2C_write(I2C1, buf[1]);

  I2C_write(I2C1, buf[2]);

  I2C_stop(I2C1);

  buf[0] = 0;

  buf[1] = 0;

  buf[2] = 0;

  I2C_start(I2C1, SLAVE_ADDR << 1 , I2C_Direction_Transmitter);

  I2C_write(I2C1, 0x00);

  I2C_restart(I2C1, SLAVE_ADDR << 1 , I2C_Direction_Receiver);

  buf[0] = I2C_read_ack(I2C1);

  buf[1] = I2C_read_ack(I2C1);

  buf[2] = I2C_read_nack(I2C1);

  I2C_stop(I2C1);

  if (buf[0] == 'H') {

    //Yipieea it works!

    GPIOC->BSRR = 1<<9 ;  //Switch green on

    GPIOC->BSRR = 1<<24;  //Switch off blue

  } else {

    GPIOC->BSRR = 1<<8;   //Switch on blue

    GPIOC->BSRR = 1<<25;  //Switch off green

  }

  while(1) ;

  return 0;

}

void nmi_handler(void)

{

    return ;

}

void hardfault_handler(void)

{

    return ;

}

#include "i2c.h"

void InitI2C()

{

    I2C_InitTypeDef I2C_InitStructure;

    GPIO_InitTypeDef GPIO_InitStructure;

    SystemInit();

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);

    /* Reset I2Cx IP */

    RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, ENABLE);

    /* Release reset signal of I2Cx IP */

    RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, DISABLE);

    GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6 | GPIO_Pin_7;

    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD; // Open Drain, I2C bus pulled high externally

    GPIO_Init(GPIOB, &GPIO_InitStructure);

    I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;

    //I2C_InitStructure.I2C_OwnAddress1 = 0x00;        //Eigene Adresse für Slave oder Multimaster betrieb, ansonsten irrelevant

    I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;

    I2C_InitStructure.I2C_Ack = I2C_Ack_Disable;

    I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;   //Adress-Modus, normalerweise 7-Bit

    I2C_InitStructure.I2C_ClockSpeed = 50000;        //Taktgeschwindigkeit von SCL, hier 50kHz

    I2C_Init(I2C1, &I2C_InitStructure);

    I2C_ITConfig(I2C1, I2C_IT_EVT | I2C_IT_BUF, DISABLE);  //Keine Interrupts

    I2C_Cmd(I2C1, ENABLE);

}

void I2C_start(I2C_TypeDef* I2Cx, uint8_t address, uint8_t direction){

  // wait until I2C1 is not busy any more

  while(I2C_GetFlagStatus(I2Cx, I2C_FLAG_BUSY));

  // Send I2C1 START condition

  I2C_GenerateSTART(I2Cx, ENABLE);

  // wait for I2C1 EV5 --> Slave has acknowledged start condition

  while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_MODE_SELECT));

  // Send slave Address for write

  I2C_Send7bitAddress(I2Cx, address, direction);

  /* wait for I2Cx EV6, check if

   * either Slave has acknowledged Master transmitter or

   * Master receiver mode, depending on the transmission

   * direction

   */

  if(direction == I2C_Direction_Transmitter){

    GPIOC->BSRR = 1<<8;   //Switch on blue

    while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); // Here it hangs...

    GPIOC->BSRR = 1<<9 ;  //Switch green on

  }

  else if(direction == I2C_Direction_Receiver){

    while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));

  }

}

void I2C_restart(I2C_TypeDef * I2Cx, uint8_t address, uint8_t direction)

{

    while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTING));

    I2Cx->CR1 |= I2C_CR1_START;

    while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

    while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_MODE_SELECT));

  // Send slave Address for write

  I2C_Send7bitAddress(I2Cx, address, direction);

  /* wait for I2Cx EV6, check if

   * either Slave has acknowledged Master transmitter or

   * Master receiver mode, depending on the transmission

   * direction

   */

  if(direction == I2C_Direction_Transmitter){

    while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

  }

  else if(direction == I2C_Direction_Receiver){

    while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));

  }

}

void I2C_write(I2C_TypeDef* I2Cx, uint8_t data)

{

  // wait for I2C1 EV8 --> last byte is still being transmitted (last byte in SR, buffer empty), next byte can already be written

  while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTING));

  I2C_SendData(I2Cx, data);

}

uint8_t I2C_read_ack(I2C_TypeDef* I2Cx){

  // enable acknowledge of received data

  I2C_AcknowledgeConfig(I2Cx, ENABLE);

  // wait until one byte has been received

  while( !I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_RECEIVED) );

  // read data from I2C data register and return data byte

  uint8_t data = I2C_ReceiveData(I2Cx);

  return data;

}

uint8_t I2C_read_nack(I2C_TypeDef* I2Cx){

  // disable acknowledge of received data

  // nack also generates stop condition after last byte received

  // see reference manual for more info

  I2C_AcknowledgeConfig(I2Cx, DISABLE);

  I2C_GenerateSTOP(I2Cx, ENABLE);

  // wait until one byte has been received

  while( !I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_RECEIVED) );

  // read data from I2C data register and return data byte

  uint8_t data = I2C_ReceiveData(I2Cx);

  return data;

}

void I2C_stop(I2C_TypeDef* I2Cx){

    while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

  // Send I2C1 STOP Condition after last byte has been transmitted

  I2C_GenerateSTOP(I2Cx, ENABLE);

  // wait for I2C1 EV8_2 --> byte has been transmitted

  while(!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

}