Accelerometer Data

Iain B. Findleton ifindleton at
Sun Mar 22 18:41:55 CET 2009

I have been playing a bit with the accelerometers on the FR appear to
observe the following:

   1) The time stamp on events appears to be unreliable, in the sense
that the time difference
       between sequential events is frequently negative, and appears
also to be have erratically
       by jumping an order of magnitude or 2 between sequentially
available events.

   2) It also appears to be relatively common that a SYN arrives before
all 3 axis values are available,
       making it hard to figure out the meaning of the data

   3) There is a significant difference between the readings of the 2
accelerometers when the FR
        is just sitting there on the desk doing nothing.

    4) When you move the FR about, the rate of reports being available
appears to become very erratic,
         in the sense that there are relatively long periods between

My questions are:

    1) Is this a common situation with the FR (OM2008.12)
    2) Is the device driver just buggy?

Of course, I realize that my own code might be just buggy, but these
features of the accelerometers
appear in both my C++ and TCL code, and in the example programs from the
wiki references with
print statements inserted.

Tks for any advice.

Iain B. Findleton
Tel: 514-457-0744

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