Re: Re : Re: accelerometer calibration

W. B. Kranendonk wankelwankel at
Sat Dec 25 23:00:55 CET 2010

--- On Sat, 12/25/10, Iain B. Findleton <ifindleton at> wrote:
> The output from
> the chip is quite noisy. 
The problem is not that the signal is not reliable: it is. It is just that it is off by a few degrees. 

> There is a script I wrote in TCL
> on the
> SourceForge web site under the fltkwish project page. It
> may give you
> some ideas about that can be done. In my experience, the
> results vary
> depending on which of the chips you use.
I have used the (a?) waterpas before, when there was such a program in the SHR repositories. I just had a shot at gravity, but there are some missing dependencies. 

It complains about
# gravity 
fltkwish: error while loading shared libraries: cannot open shared object file: No such file or directory

I tcl, fltk and fltkwish installed and is available
I symlinked it to
 # ls -latr /usr/lib/libtcl8.*
-r-xr-xr-x    1 root     root        663504 May 29  2010 /usr/lib/
lrwxrwxrwx    1 root     root            14 Dec 23 20:17 /usr/lib/ ->

Now it aborts with just that:
# gravity 

Perhaps another time :-)

> Note that on the iPhone, some versions of which used the
> same chip, you
> only get access to the 100/sec samples, 
On a sidenote: long live closed platforms

> The other issues is there was at one time some confusion
> about how the
> driver reported through the event mechanism. I forget the
> details now,
> but working code depended on how up to date your kernel
> was. If you have
> a kernel of recent vintage, should not be an issue.
It's the latest SHR:
# uname -a
Linux om-gta02 #1 Sun Dec 5 23:10:39 CET 2010 armv4tl GNU/Linux

I wonder (..doubt..) if the issue is in the software, because it has been like this over the last half year or so, with different distro's and no problems on the other FR with the same version of a distro.

Thanks for the insight anyway!



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