STM32 I2C Problem

[Jan Dijkstra (Gast)]

Hallo,

ich versuche mit einem STM32F103RCT6 ein Register von MPU6050 über I2C 
unter Verwendung std-cmsis-lib auszulesen. Es lässt sich problemlos 
beschreiben, nur das auslesen zum zweiten geht nicht mehr.

Hier ist mein Code:

#define MPU6050   ((uint8_t) 0x68)

void RCC_Configuration(void) {
    /* GPIOB clock enable */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
    /* I2C clock enable */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
}


void GPIO_Configuration(void) {
    GPIO_InitTypeDef GPIO_InitStructure;

    /* I2C1 PB6 = SCL, PB7 = SDA Pin Configuration */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
}

void I2C_Configuration(void) {
    I2C_InitTypeDef I2C_InitStructure;

    I2C_DeInit(I2C1);

    I2C_InitStructure.I2C_ClockSpeed = 400000; // 400kHz
    I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStructure.I2C_OwnAddress1 = 0x00;
    I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_Init(I2C1, &I2C_InitStructure);

    I2C_Cmd(I2C1, ENABLE);
}


void I2C_start(I2C_TypeDef* I2Cx, uint8_t address, uint8_t direction) {
  trace_puts("i2c start\n");
  while (I2C_GetFlagStatus(I2Cx, I2C_FLAG_BUSY));

    I2C_GenerateSTART(I2Cx, ENABLE);
    while (!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_MODE_SELECT));
    I2C_Send7bitAddress(I2Cx, address, 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) {
    trace_puts("i2c write\n");
  I2C_SendData(I2Cx, data);
    while (!I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
}

uint8_t I2C_read_nack(I2C_TypeDef* I2Cx) {
  trace_puts("i2c read nack\n");

    I2C_AcknowledgeConfig(I2Cx, DISABLE);
    while ( !I2C_CheckEvent(I2Cx, I2C_EVENT_MASTER_BYTE_RECEIVED) ) {
        trace_printf("i2c read nack stuck\n");
    }
    uint8_t data = I2C_ReceiveData(I2Cx);

    return data;
}

void I2C_stop(I2C_TypeDef* I2Cx) {
    trace_puts("i2c stop\n");

    I2C_GenerateSTOP(I2Cx, ENABLE);

    // Wait until I2C stop condition is finished
    while (I2C_GetFlagStatus(I2Cx, I2C_FLAG_STOPF));
}

/* Single-Byte Read Sequence*/
uint8_t Read_Reg(uint8_t reg_adr) {
    I2C_start(I2C1, MPU6050 << 1, I2C_Direction_Transmitter);
    I2C_write(I2C1, reg_adr);
    I2C_stop(I2C1);

    I2C_start(I2C1, MPU6050 << 1, I2C_Direction_Receiver);
    uint8_t received_data = I2C_read_nack(I2C1);
    I2C_stop(I2C1);
    return received_data;
}

int main(void) {
  System_Clock_Setup();

  RCC_Configuration();
  GPIO_Configuration();
  I2C_Configuration();

  trace_puts("Hello\n");
  Delay(1e5);
  while (1) {
    trace_puts("loop begin\n");

    uint8_t addr = Read_Reg(0x75);
    trace_printf("addr: %i\n", addr);
                Delay(1e4);
  }
}

Debug Ausgabe:

Hello
loop begin
i2c start
i2c write
i2c stop
i2c start
i2c read nack
i2c stop
addr: 104
loop begin
i2c start
i2c write
i2c stop
i2c start
i2c read nack

i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck
i2c read nack stuck

Weiss jemand zufällig woran es liegt?
Vielen Dank im Voraus.

[Jan Dijkstra (Gast)]

übrigens lässt sich der MPU6050 problemlos von einem STM32F4 uC mit dem 
selben Code im Wesentlichen auslesen.

[Uwe B. (Firma: TU Darmstadt) (uwebonnes)]

I2C bei F1 und F4 unterscheiden sich deutlich.

[Stm M. (stmfresser)]

Pull-Up Widerstände evtl. zu gross?

[Jan Dijkstra (Gast)]

Stm M. schrieb:
> Pull-Up Widerstände evtl. zu gross?

Ne die sind 4k7