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    BMA-4xx acc issue

    BMA-4xx acc issue

    New Poster

    Hello, BOSCH

    No other than that, I have an inquiry about the acc value of each of the three axes of the BMA4XX model.

    Both BMA422 and 455 read the chip ID well, and the acc and temperature values of each axis are also read.

    However, with no movement at all, the acc upper byte value fluctuates greatly, while the lower byte remains almost unchanged.
    It's like the upper and lower bytes are switched

    - Please advise if there are any points to modify.

    For example, if you put the board on the floor and didn't move,
    - The acc_x low byte (0x12 register) value remains unchanged
    - The acc_x high byte (0x13 register) value is highly variable.
    - The y and z axes are the same.

    For your information, after resetting, initialization proceeded as below.
    0x41 Register - 0x00 write (+-2g used)
    0x40 register - 0xAC write (Performance, Normal mode, 1600Hz sampling)
    0x7D register - 0x04 write (accessable, aux disable)

    If you use it as it is, the movement will be detected continuously, so if there's anything that can help you find the cause, Please answer that.

    7 REPLIES 7

    Community Moderator
    Community Moderator

    Hi mgchoi,

    1. Did you have shuttle board and application board? If you have them, you could test sensor on development desktop software. And compare the test data with your hardware.
    2. You could run sensor API example code, and see the test result.

    Hello, BSTRobin

    After conducting the test with Shuttle and Application Board, there is no problem
    So what kind of problem can we look at?

    Community Moderator
    Community Moderator

    Hi mgchoi,

    You could run official example code on shuttle board and application board first. As it works well, then you can run the same code on your hardware. If it doesn't work, you can check your hardware.

    Hi, BSTRobin

    I checked and found that Dummy Byte was the problem. Thank you!