Mechanical Drawings for the ADIS16475-3 Breakout Board

Hi,

I am using the breakout board for the ADIS16475-3 and I want to do a few mechanical tests to the board. However, the mechanical information on pages 32 and 33 of the datasheet do not give all the measurements necessary for what I am trying to accomplish.

To be specific, I am trying to align along the point of percussion. Unfortunately, I could not determine the measurement value for where this lies on the breakout board. I do know that the point of percussion is centered on pin A1 which lies in the bottom right corner of the device when looking from above. While that is helpful, trying to determine where that is in relation to the IMU's placement on the breakout board has proven quite difficult. A more detailed mechanical drawing with measurements or an explanation of how to obtain the location of this point of percussion in reference to the entire board would be much appreciated!

  • Thank you for your post.  I will be glad to help, but would like ask if you can help us understand how this will influence your application.  The breakout board was not intended to support this level of mechanical resolution/precision, but if you can help us understand the level of accuracy that you need (a level more precise than, "as good as possible."), I will be glad to review this and see what I can find for you.

  • I am planning to rotate the board around the z-axis for survivability purposes. To do this, I would like to be as centered as possible around the point of percussion which lies in the bottom right corner. Since the z-axis comes straight up out of A1, I would like to know how far pin A1 is from the edges of the board. In terms of accuracy, the mechanical drawing has values listed to the hundredth and/or thousandth of a millimeter.

    On another note, I am curious as to what happens when you disable the point of percussion calibration setting in register MSC_CTRL, bit 6. When disabled, does the point of percussion move to the center of the device? A more detailed explanation of what is occurring there would also be very helpful.

    Thank you for your timely response!

  • Thank you for this information. I appreciate the information and the effort, but this wasn't exactly what I was hoping for.  Let me rephrase and re-submit my request in the form of three questions:

    1. What are you trying to measure?
    2. What level of accuracy are you trying to achieve?
    3. How does the location of the POP influence this measurement?
    • The number of digits that we offer for the dimensions (in the figure) does not imply tolerance/precision and would not seem to have much to do with how this metric will impact your objectives.
    • I am not trying to be difficult, but it is difficult to know when we have succeed, when we are asked to take responsibility for a subjective goal, like "as close as possible."
    • I am willing to do some work to help you, but I am asking you to help me understand the sensitivity, in return for that effort.  I am already working on this for you, so this is not a demand, but is a hopeful request....
    • When you turn this function off, the point of percussion doesn't move, it ceases to exist.  This is the only available mechanism for understanding the location of the accelerometer origin for all three axes.  I hope that answers this question.
  • Here are the dimensions.  Please keep in mind that the CAD tool automatically offers 3 decimal places; that doesn't imply the level of precision in the measurement.  I hope that this helps.