Thanks steve,
after some tests it seemed to be the reason. power-off and clean helped.
Another problem I had was the following. Suppose you have three gyros
(500 deg/s) and one gyro (2000 deg/s). After about 30 minutes you see a
shifted signal in the 2000 deg/s one compared to the other three
(assumption: same movement pattern was done).
Has anyone also have expericences with that?
Best regards,
Dominik
Am 26.01.2012 14:05, schrieb steve ayer:
hi dominik,
it's not the sd, it's the start-up behavior of the gyro.
this is a guess, albeit an educated one, but does the gyro act up
mainly after you re-program the shimmer? does it clear up after a
number of hard power cycles?
what's happening: during programming, in order to enter the bsl
sequence, and sequence of resets is sent to the msp430. these can
leave the gyroscope in a confused state, and the only way to clear it
is a complete power-down and a clean (uninterrupted by resets)
power-on. that's why the gyro driver does this, with a (iirc)
six-second pause. occasionally the six seconds isn't enough, but it
does suffice in light of the fact that (most) people don't re-program
the shimmer every time they use it!
i hope that this helps,
steve
On 01/26/2012 04:43 AM, Dominik Schuldhaus wrote:
Hi,
I have the following problem.
The shimmer-firmware I use is able to write accel & gyro on SD card. The
accelerometer values seem to be fine for every
trial/record. But the behaviour of the gyroscope is strange. Sometimes
one/two axes fail, sometimes all.
There are also other strange artefacts.
Does anyone have experience with gyroscope on SD?
Best regards,
Dominik
--
Dipl.-Ing. Dominik Schuldhaus
Digital Sports Group
Pattern Recognition Lab
Friedrich-Alexander-University Erlangen-Nuremberg
Haberstr. 2, 91058 Erlangen, Germany
Phone: +49 (0)9131 / 85-27890
E-Mail: [email protected]
Web: www5.informatik.uni-erlangen.de/~schuldhaus
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