STM32 und I2C - Fehler im Code

#include "stm32f10x_conf.h"

//#include "stm32f10x.h"

void Init(void){

// Hardware initialiser

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);                // enable I2C;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);                // enable alternate functions (why?);

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);               // GPIO C enable

    GPIO_InitTypeDef gpioInit;

    gpioInit.GPIO_Mode = GPIO_Mode_Out_OD;

    gpioInit.GPIO_Speed = GPIO_Speed_2MHz;

    gpioInit.GPIO_Pin = GPIO_Pin_13;

    GPIO_Init(GPIOC, &gpioInit);

    GPIO_WriteBit(GPIOC, ((uint16_t)0x2000), Bit_SET);

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);               // GPIO B enable

    GPIO_InitTypeDef gpioInit1;

    gpioInit1.GPIO_Mode = GPIO_Mode_AF_OD;

    gpioInit1.GPIO_Speed = GPIO_Speed_50MHz;

    gpioInit1.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;                       // route I2C pins

    GPIO_Init(GPIOB, &gpioInit1);

    NVIC_InitTypeDef NVICinit;                                          // configure NVIC

    NVICinit.NVIC_IRQChannel = I2C1_EV_IRQn;                            // add I2C_event interrupt

    NVICinit.NVIC_IRQChannelPreemptionPriority = 0;

    NVICinit.NVIC_IRQChannelSubPriority = 0;

    NVICinit.NVIC_IRQChannelCmd = ENABLE;

    NVIC_Init(&NVICinit);

    NVICinit.NVIC_IRQChannel = I2C1_ER_IRQn;                            // add I2C_error interrupt

    NVICinit.NVIC_IRQChannelPreemptionPriority = 0;

    NVICinit.NVIC_IRQChannelSubPriority = 0;

    NVICinit.NVIC_IRQChannelCmd = ENABLE;

    NVIC_Init(&NVICinit);

    I2C_DeInit(I2C1);                                                   // init I2C module

    I2C_InitTypeDef I2Cinit;

    I2Cinit.I2C_Ack = I2C_Ack_Enable;

    I2Cinit.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

    I2Cinit.I2C_ClockSpeed = 100000;

    I2Cinit.I2C_DutyCycle = I2C_DutyCycle_2;

    I2Cinit.I2C_Mode = I2C_Mode_I2C;

    I2Cinit.I2C_OwnAddress1 = 0;

    I2C_Init(I2C1, &I2Cinit);

    I2C_ITConfig(I2C1, I2C_IT_EVT, ENABLE);                             // enable event, error and buffer interrupts

    I2C_ITConfig(I2C1, I2C_IT_ERR, ENABLE);

    I2C_ITConfig(I2C1, I2C_IT_BUF, ENABLE);

    I2C_Cmd(I2C1, ENABLE);

}

volatile uint8_t I2C_errorcode = 0, I2C_addr = 0, I2C_num_bytes = 0;

volatile uint8_t* I2C_reading_pointer;

static uint8_t OLED_init[29]= {                                          // Initialization Sequence

0x00,                                                                   // Commands will be sent

0xAE,                                                              // Display OFF (sleep mode)

0x20, 0b00,                                                            // Set Memory Addressing Mode

                                                                        // 00=Horizontal Addressing Mode; 01=Vertical Addressing Mode;

                                                                        // 10=Page Addressing Mode (RESET); 11=Invalid

0xB0,                                                              // Set Page Start Address for Page Addressing Mode, 0-7

0xC8,                                                              // Set COM Output Scan Direction

0x00,                                                                // --set low column address

0x10,                                                              // --set high column address

0x40,                                                              // --set start line address

0x81, 0x3F,                                                            // Set contrast control register

0xA1,                                                              // Set Segment Re-map. A0=address mapped; A1=address 127 mapped.

0xA6,                                                              // Set display mode. A6=Normal; A7=Inverse

0xA8, 63,                                                            // Set multiplex ratio(1 to 64)

0xA4,                                                              // Output RAM to Display

                                                                        // 0xA4=Output follows RAM content; 0xA5,Output ignores RAM content

0xD3, 0x00,                                                            // Set display offset. 00 = no offset

0xD5,                                                              // --set display clock divide ratio/oscillator frequency

0xF0,                                                              // --set divide ratio

0xD9, 0x22,                                                            // Set pre-charge period

0xDA, 0x12,                                                            // Set com pins hardware configuration

0xDB,                                                              // --set vcomh

0x20,                                                              // 0x20,0.77xVcc

0x8D, 0x14,                                                            // Set DC-DC enable

0xAF                                                                    //?

};

    void I2C1_EV_IRQHandler(){                                              // Self-containing I2C interrupt

        if(I2C1->SR1 & I2C_SR1_SB){                                         // triggered by start condition ->

            I2C1->DR = I2C_addr;                                            // send I2C adress

        }else if((I2C1->SR1 & I2C_SR1_ADDR)||(I2C1->SR1 & I2C_SR1_TXE)){    // if not, then send data

           if(I2C_num_bytes){                                               // in case its available

                I2C1->DR = *I2C_reading_pointer;

                I2C_reading_pointer++;

                I2C_num_bytes--;

            }

        }                                                                   // if not - send stop condition

        else if((I2C1->SR1 & I2C_SR1_BTF)){

            I2C1->CR1 |= ((uint16_t)0x0200);                                // EmBitz does not recognize CR1_STOP_Set

            I2C_errorcode = 0;

        }

    }

    void I2C1_ER_IRQHandler(){

        if(I2C1->SR1 & I2C_SR1_AF)

            I2C_errorcode = 1;                                              // No devise with that adress

        else{

            I2C_errorcode = 2;                                              // Something strange occured, inspect SR1

        }

    }

    void I2C_initiate_transmission(){                                       // it`s fire and forget

        while(I2C1->SR2 & I2C_SR2_BUSY){}                                   // wait for the bus to become free (maybe not required)

        I2C1->CR1 |= ((uint16_t)0x0100);                                    // send start condition; EmBitz doesnt recognize it also

        I2C_errorcode = -1;                                                 // lock the I2C variables

    }

int main(void)

{

    Init();

    I2C_reading_pointer = OLED_init;

    I2C_num_bytes = 29;

    I2C_addr = 0x78;

    I2C_initiate_transmission();

    while(I2C_errorcode != 0){}

    uint8_t foo[2] = {0x40,0xff};

    I2C_reading_pointer = foo;

    I2C_num_bytes = 2;

    I2C_initiate_transmission();

  while(1)

  {

  }

}