yeah,
true. but the sd driver power cycles the card, waiting twice as long as
the sd-spec's power down timing. determined empirically, sandisk always
meets the spec (20 ms), and a couple of other brands come close (don't
remember which ones).
but still, usually this problem has to do with host drivers.
-steve
On 02/29/2012 09:08 AM, Benjamin Kuris wrote:
There is power timing variability in sd card brands- try sandisk
You could also try a power cycle (wait 10 seconds in off state) on your
shimmers vs removing cards which is giving a definite power down to reset media
from spi to sd mode
On Feb 29, 2012, at 7:57 AM, steve ayer<[email protected]> wrote:
hi klaus,
this is a host-side issue, with different drivers and operating
systems/environments giving varying results.
"do not adjust your set. the trouble is not in your set."
i wish i had better news,
steve
On 02/29/2012 06:02 AM, Klaus-Hendrik Wolf wrote:
Dear all,
For one of our new settings we would like to use the shimmer as a
recording device only and have the subjects collect the data from the SD
card via an USB connected dock.
During our testing we came across a problem which hopefully you know how
to solve or work around.
Inserting the shimmer into the dock *sometimes* results in it being
discovered by the connected computer as a new medium in the
corresponding block device (monitored with udevadm monitor).
With my latest tests this *sometimes* unfortunately means: not very often.
We first discovered this behavior with our own firmware, but it is
reproducible with the justfatlogging app as well. I have tested at least
four different shimmers (2r), so it should not be a hardware problem.
I tried different combinations of resetting the shimmer (in and out of
the dock), disconnecting and reconnecting the dock (shimmer in and out),
but found no combination that is working in most cases.
A work-around for justfatlogging i have found is to remove the SD card,
reset the shimmer, insert the card and after that put it in the dock.
But disassembling and removing the SD card is not really an option for
our study.
Does anyone of you have an idea how to make docking more reliable?
If it is only one out of three it would still be OK.
Even a workaround would be welcome! (As long as it does not involve
opening the shimmer)
Best regards,
Klaus Hendrik
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