STMF4xx MPU6050

Tengo problemas con la lectura de datos de MPU6050 a la placa del núcleo STM32F4. La conexión es con I2C. El problema es que en la primera función IsDeviceReady, el dispositivo se reconoce y el LED se enciende, pero cuando configuro los datos en i2cBuf [1] = 0x08 y los envío, después de recibir esos datos, i2cBuf [1] se configura en 0x00 - así como se establece antes de recibir los datos. ¿Tal vez sabes cuál podría ser el problema? Gracias.

Código:

#include "stm32f4xx_hal.h"
#include <string.h>


void GPIO_Config(void);
void I2C_Config(void);
void UART_Config(void);
void DMA_Config(void);

#define mpu6050Address 0xD0

I2C_HandleTypeDef MBI2Chandle;
UART_HandleTypeDef MBUARThandle;
DMA_HandleTypeDef MBDMA_Uart2Handle;

//UART Test
char txData[40] = "Hello from STM\r\n";
char rxData[40];

//I2C variables
uint8_t i2cBuf[8];
int16_t ax,ay,az;
float Xaccel, Yaccel, Zaccel; 


int main(void)
{
//HAL Initialise
HAL_Init();

//Config functions
GPIO_Config();
I2C_Config();
UART_Config();
DMA_Config();


//1. Scan the I2C adresses
for(uint8_t i=0; i<255; i++)
{
    if(HAL_I2C_IsDeviceReady(&MBI2Chandle, i, 1, 10) == HAL_OK)          //test for the slave address
    {
        HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_7);
        break;
    }
}



//2. I2C Write example
//a) Set accelerometer range (reg28)
i2cBuf[0] = 28;         //Register address: Accelerometer config 1 
i2cBuf[1] = 0x08;       //Data to write, +-4g range
HAL_I2C_Master_Transmit(&MBI2Chandle, mpu6050Address, i2cBuf, 2, 10);


//3. I2C Read example
//Request to read from a register (reg 28)
i2cBuf[0] = 28;     //Register address: Accelerometer config 1
HAL_I2C_Master_Transmit(&MBI2Chandle, mpu6050Address, i2cBuf, 1, 10);
//Read data
i2cBuf[1] = 0x00;
HAL_I2C_Master_Receive(&MBI2Chandle, mpu6050Address|0x01, &i2cBuf[1], 1, 10);



while(1)
{
    /*

    //4.Read accelerometer data
    //Request to read from a register
    i2cBuf[0] = 0x3B;       //Register address: X_axis H
    HAL_I2C_Master_Transmit(&MBI2Chandle, mpu6050Address, i2cBuf, 1, 10);
    //Read data
    i2cBuf[1] = 0x00;
    HAL_I2C_Master_Receive(&MBI2Chandle, mpu6050Address|0x01, &i2cBuf[1], 6, 10);

    ax= -(i2cBuf[1]<<8 | i2cBuf[2]);
    ay= -(i2cBuf[3]<<8 | i2cBuf[4]);
    az= -(i2cBuf[5]<<8 | i2cBuf[6]);

    Xaccel = ax/8192.0;
    Yaccel = ay/8192.0;
    Zaccel = az/8192.0;
    HAL_Delay(50);

    */

    //UART Test
    HAL_UART_Transmit(&MBUARThandle, (uint8_t *)txData, strlen(txData), 10);
    HAL_Delay(500);

}


  }

   void GPIO_Config(void)
  {
   //Enable Ports clocks
__HAL_RCC_GPIOD_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();

//Init typeDef
GPIO_InitTypeDef MBPinInit;

//LED pins config
    //PB7 BLUE LED
MBPinInit.Pin = GPIO_PIN_7;
MBPinInit.Mode = GPIO_MODE_OUTPUT_PP;
MBPinInit.Pull = GPIO_NOPULL;
MBPinInit.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOB, &MBPinInit);

//I2C pins config
    //I2C1_SCL PB8, I2C1_SDA PB9
MBPinInit.Pin = GPIO_PIN_8 | GPIO_PIN_9;
MBPinInit.Mode = GPIO_MODE_AF_OD;
MBPinInit.Pull = GPIO_PULLUP;
MBPinInit.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
MBPinInit.Alternate = GPIO_AF4_I2C1;
HAL_GPIO_Init(GPIOB, &MBPinInit);

//Systick interrupt enable for HAL_Delay function
HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);
HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);


}


void UART_Config(void)
{
__HAL_RCC_GPIOD_CLK_ENABLE();
__HAL_RCC_USART2_CLK_ENABLE();

GPIO_InitTypeDef MBUartDef;
MBUartDef.Pin = GPIO_PIN_5 | GPIO_PIN_6;
MBUartDef.Mode = GPIO_MODE_AF_PP;
MBUartDef.Pull = GPIO_PULLUP;
MBUartDef.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
MBUartDef.Alternate = GPIO_AF7_USART2;
HAL_GPIO_Init(GPIOD, &MBUartDef);

//UART Configuration
MBUARThandle.Instance = USART2;
MBUARThandle.Init.BaudRate = 115200;
MBUARThandle.Init.Mode = UART_MODE_TX_RX;
MBUARThandle.Init.WordLength = UART_WORDLENGTH_8B;
MBUARThandle.Init.StopBits = UART_STOPBITS_1;
MBUARThandle.Init.OverSampling = UART_OVERSAMPLING_16;
HAL_UART_Init(&MBUARThandle);

//System interrupt enable
HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);
HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);

}


void I2C_Config(void)
{
//Enable I2C peripheral clock
__HAL_RCC_I2C1_CLK_ENABLE();

MBI2Chandle.Instance = I2C1;
MBI2Chandle.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
MBI2Chandle.Init.ClockSpeed = 100000;
MBI2Chandle.Init.DualAddressMode = I2C_DUALADDRESS_DISABLED;
MBI2Chandle.Init.DutyCycle = I2C_DUTYCYCLE_2;
MBI2Chandle.Init.GeneralCallMode = I2C_GENERALCALL_DISABLED;
MBI2Chandle.Init.GeneralCallMode = I2C_NOSTRETCH_DISABLED;
MBI2Chandle.Init.OwnAddress1 = 0;
MBI2Chandle.Init.OwnAddress2 = 0;
HAL_I2C_Init(&MBI2Chandle);

}

void SysTick_Handler(void)
 {
HAL_IncTick();
HAL_SYSTICK_IRQHandler();
}


void DMA_Config(void)
{
__HAL_RCC_DMA1_CLK_ENABLE();
MBDMA_Uart2Handle.Instance = DMA1_Stream5;      //pdf str 196
MBDMA_Uart2Handle.Init.Channel = DMA_CHANNEL_4;
MBDMA_Uart2Handle.Init.Direction = DMA_PERIPH_TO_MEMORY;
MBDMA_Uart2Handle.Init.PeriphInc = DMA_PINC_DISABLE;
MBDMA_Uart2Handle.Init.MemInc = DMA_MINC_ENABLE;
MBDMA_Uart2Handle.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
MBDMA_Uart2Handle.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
MBDMA_Uart2Handle.Init.Mode = DMA_CIRCULAR;
MBDMA_Uart2Handle.Init.Priority = DMA_PRIORITY_LOW;
MBDMA_Uart2Handle.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
HAL_DMA_Init(&MBDMA_Uart2Handle);

__HAL_LINKDMA(&MBUARThandle, hdmarx, MBDMA_Uart2Handle);

//Enable DMA1 Stream 5 interrupt
HAL_NVIC_SetPriority(DMA1_Stream5_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn);

}

 void DMA2_Stream5_IRQHandler(void)
{
HAL_DMA_IRQHandler(&MBDMA_Uart2Handle);
}