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Thanks for giving me an example from STM32. Reading the implementation for 'HAL_I2C_Master_Transmit' and 'HAL_I2C_Master_Receive' answered my question. For all those who are going to read this subject the answer is: Yes, after leaving BMA2x2_BUS_READ_FUNC the complete data has to be in "data_u8" buffer. So the whole API relies on a synchronous interface. No matter if you get data form I2C using pooling or interrupts the BMA2x2_BUS_READ_FUNC function must not return until all data is read. ... View more

Thanks for your reply BSTRobin, I would like to be more precise in my question. I would like to confirm that after leaving function "p_bma2x2->BMA2x2_BUS_READ_FUNC" which I've marked with "(A) read from a bus"  the "data_u8" has to be filled with all 6 bytes of accelerometer data in order to whole operation of reading  accelerometer data from X,Y,Z be successful. That is what I meant when I was asking if the whole API is designed to be used in a synchronous way. Am I correct or am I missing something obvious?   BMA2x2_RETURN_FUNCTION_TYPE bma2x2_read_accel_xyz( struct bma2x2_accel_data *accel) { /* Variable used to return value of communication routine*/ BMA2x2_RETURN_FUNCTION_TYPE com_rslt = ERROR; /* Array holding the accel xyz value data_u8[0] - x->LSB data_u8[1] - x->MSB data_u8[2] - y->MSB data_u8[3] - y->MSB data_u8[4] - z->MSB data_u8[5] - z->MSB */ u8 data_u8[BMA2x2_ACCEL_XYZ_DATA_SIZE] = { BMA2x2_INIT_VALUE, BMA2x2_INIT_VALUE, BMA2x2_INIT_VALUE, BMA2x2_INIT_VALUE, BMA2x2_INIT_VALUE, BMA2x2_INIT_VALUE }; if (p_bma2x2 == BMA2x2_NULL) { /* Check the struct p_bma2x2 is empty */ return E_BMA2x2_NULL_PTR; } else { switch (V_BMA2x2RESOLUTION_U8) { (...) /* This case used for the resolution bit 14*/ case BMA2x2_14_RESOLUTION: com_rslt = p_bma2x2->BMA2x2_BUS_READ_FUNC( // <--------------------------------------------- (A) read from a bus p_bma2x2->dev_addr, BMA2x2_ACCEL_X12_LSB_REG, data_u8, BMA2x2_SHIFT_SIX_BITS ); /* read the x data_u8*/ accel->x = (s16) ((((s32) ((s8) data_u8[BMA2x2_SENSOR_DATA_XYZ_X_MSB])) << BMA2x2_SHIFT_EIGHT_BITS) | (data_u8[BMA2x2_SENSOR_DATA_XYZ_X_LSB] & BMA2x2_14_BIT_SHIFT)); accel->x = accel->x >> BMA2x2_SHIFT_TWO_BITS; /* read the y data_u8*/ accel->y = (s16) ((((s32) ((s8) data_u8[BMA2x2_SENSOR_DATA_XYZ_Y_MSB])) << BMA2x2_SHIFT_EIGHT_BITS) | (data_u8[BMA2x2_SENSOR_DATA_XYZ_Y_LSB] & BMA2x2_14_BIT_SHIFT)); accel->y = accel->y >> BMA2x2_SHIFT_TWO_BITS; /* read the z data_u8*/ accel->z = (s16) ((((s32) ((s8) data_u8[BMA2x2_SENSOR_DATA_XYZ_Z_MSB])) << BMA2x2_SHIFT_EIGHT_BITS) | (data_u8[BMA2x2_SENSOR_DATA_XYZ_Z_LSB] & BMA2x2_14_BIT_SHIFT)); accel->z = accel->z >> BMA2x2_SHIFT_TWO_BITS; break; default: break; } } return com_rslt; }     ... View more

The IC was broken. After replacing corrupted sensor with the new one I do not have to do any additional configuration or clearing FIFO buffer first in order to read data from FIFO buffer. FIFO reading works by default after power up. The only thing that needs to be changed (in order to read data from gyro in a FIFO  way) is to set FIFO register address as the one that you want to read from. ... View more

Thanks Yanchao, I was not replying so long because in spite of trying to read the data as you instructed me I still receive wrong values. I bought BMX055 shuttle board and will see if the problem will be solved. Maybe my current IC is broken. ... View more