STM32F3 I2C read data - embedded

Question

I'm using the STM32F373 microcontroller and wrote a simple function to read data from a MPU6050 gyro+accel on i2c 1 (PB7 PB6).
The problem is that when I try to read sensor register data - flag I2C_ISR_TXIS is always equal to RESET (not set).
Why might this happen?
Here is some source code that demonstrates the problem.
void i2c1_init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
I2C_InitTypeDef I2C_InitStructure;
RCC_I2CCLKConfig(RCC_I2C1CLK_SYSCLK);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_4);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_4);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_Init(GPIOB, &GPIO_InitStructure);
I2C_DeInit(I2C1);
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Enable;
I2C_InitStructure.I2C_DigitalFilter = 0x00;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStructure.I2C_Timing = 0xC062121F;
I2C_Init(I2C1, &I2C_InitStructure);
I2C_Cmd(I2C1, ENABLE);
}
uint8_t i2c_read(uint8_t DeviceAddr, uint8_t RegAddr, uint8_t* pBuffer, uint16_t len)
{
/* Test on BUSY Flag */
uint32_t timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_ISR_BUSY) != RESET)
{
if((timeout--) == 0) return 0;
}
I2C_TransferHandling(I2C1, DeviceAddr, 1, I2C_SoftEnd_Mode, I2C_Generate_Start_Write);
/* !!! Wait until TXIS flag is set !!! */
timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_ISR_TXIS) == RESET) // PROBLEM HERE!!!!!!!!!!!!!!!
{
if((timeout--) == 0) return 0;
}
....
....
}

Answer 1

OK,I found the problem. Flag I2C_ISR_TXIS did not get because the device on the i2c did not respond to the sent address. Need to convert the device address to 7 bits.
(DeviceAddr & 0x7f) << 1