User:MartinDengler: Difference between revisions

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== About Me ==

I program for a living. I got an XO to support the OLPC project and have a laptop for daily use.

I work with python and use Fedora a lot.

See also [http://wiki.sugarlabs.org/go/User:MartinDengler My SugarLabs page]

== Bugs I'm interested in ==

[http://dev.laptop.org/query?status=assigned&status=new&status=reopened&cc=~mtd&order=priority&col=id&col=summary&col=status&col=type&col=priority&col=milestone&col=component Cced]

[http://dev.laptop.org/query my own]


== kernel module building for compcache ==

To build a kernel module on a joyride XO, ensure you have make and gcc (yum -y install make gcc should do it) and then try:
<pre>
#get joyride kernel-devel rpm
wget http://dev.laptop.org/~dilinger/{stable,testing}/kernel-devel-`uname -r`.i586.rpm
sudo rpm -ivh kernel-devel-`uname -r`.i586.rpm
sudo cp -af /boot/* /versions/boot/current/boot/
#get compcache
wget http://compcache.googlecode.com/files/compcache-0.3.tar.gz
tar xzf compcache-0.3.tar.gz
cd compcache-0.3
make
#use it
sudo ./use_compcache.sh
</pre>

== XO/OLPC mini-projects ==

I'm interested in helping with:

* {{Trac|2954|Implementing ebook mode}}
* {{Trac|4646|Sugar grabs too many shortcut keys}}
* and anything else that looks interesting

== Ambient temperature tracking ==

<pre>
bash-3.2$ cat /ofw/openprom/model ; echo
CL1 Q2D13 Q2D
bash-3.2$ cat /boot/olpc_build
update.1 691
bash-3.2$ for f in /sys/class/power_supply/olpc-battery/temp* ; do (echo -e $f\\t ; cat $f) | paste - - ; done
/sys/class/power_supply/olpc-battery/temp 2783
/sys/class/power_supply/olpc-battery/temp_ambient 3900
</pre>

bemasc explained things on #olpc [I edited out background chatter]:
<pre>
bemasc: "ambient" means "ambient in the case"
bemasc: battery means in the battery compartment
bemasc: the "ambient" thermometer is on the motherboard
bemasc: not sure which chip
bemasc: they were trying to place in the antenna
bemasc: so that it would be far from the heat sources
mtd: bemasc: so I guess if I want to know the temperature outside the case, the lower of the two numbers is closer to that (though still quite inaccurate)
bemasc: the battery temp is closest, yeah
bemasc: if you have another thermometer, you might consider trying to work out the offset and correct for it
bemasc: it'll be different depending on whether the battery is charging or discharging, and how fast
bemasc: and it'll take at least a few minutes to stabilize
bemasc: so it's not easy, but it's also not impossible
</pre>


== Misc snippets to remember ==
Backlight and blurring switched off, makes some pdfs more readable:
<pre>
su -c "echo 1 > /sys/devices/platform/dcon/output"
</pre>


== How to explicitly forget/add a WPA wireless network ==

If you want to forget/add a WPA wireless network explicitly, stop NetworkManager (/etc/init.d/NetworkManader stop) and edit
<pre>
/home/olpc/.sugar/default/nm/networks.cfg
</pre>


== Screen battery status hint ==

<pre>
Date: Sat, 5 Jan 2008 18:09:19 +0000
From: Martin Dengler <martin@martindengler.com>
Subject: Battery capacity in screen hardstatus line hint
To: devel@lists.laptop.org

[-- PGP output follows (current time: Sat 05 Jan 2008 06:23:51 PM GMT) --]
gpg: Signature made Sat 05 Jan 2008 06:09:19 PM GMT using DSA key ID 75C7D2F8
[GNUPG:] SIG_ID AwM6Me4nlHAq/mT0qRJbz79n4sk 2008-01-05 1199556559
[GNUPG:] GOODSIG 81B444DD75C7D2F8 martin@martindengler.com
gpg: Good signature from "martin@martindengler.com"
[GNUPG:] VALIDSIG 565C8F33ABF72DAA33DEB9CB81B444DD75C7D2F8 2008-01-05 1199556559 0 3 0 17 2 01 565C8F33ABF72DAA33DEB9CB81B444DD75C7D2F8
[GNUPG:] TRUST_ULTIMATE
[-- End of PGP output --]

[-- The following data is signed --]

Hi,

In case this is of use to anyone, I've put the battery capacity in my
xo screen instance's hardstatus line with this tiny script & screenrc
change:

---------- /home/olpc/bin/olpc_screen_status.sh
#!/bin/bash
# Author: Martin Dengler <martin@martindengler.com>
# idea from http://www.mail-archive.com/screen-users@gnu.org/msg00322.html
# based on battery info from olpc-logbat
#
B_INFO=/sys/class/power_supply/olpc-battery

while true
do
CAP=`cat $B_INFO/capacity`
echo b:$CAP%
sleep 60
done
----------

....screenrc change:

---------- /home/olpc/bin/.screenrc
# run command forever and assign most recent output to string escape %1`
backtick 1 0 0 /home/olpc/bin/olpc_screen_status.sh

# the ...%1`... part at the end is the important part
hardstatus alwayslastline "%{.bW}%-w%{.rW}%n %t%{-}%+w %=%{..G} %H %{..Y} %m/%d %C%a %1` "
----------

</pre>

I'd be interested to know how to get at the ambient temperature sensor
mentioned in section 2.4.1 of the CL1 hardware design specification
PDF. I've had a look around /sys/class but nothing's jumped out at
me.

== Other useful OLPC hints ==

http://www.catmoran.com/olpc

== Activity Installation fu ==

<pre>
From: Gary C Martin <gary@garycmartin.com>
Subject: Re: Playing w/ Activity packs in build 702

> Can anyone tell me how to install TamTam from scratch?

Not sure if this is the official way â but hidden in the update-
activities.py script from Bert Freudenberg is a very useful link to a
whole bunch of .xo builds, not all of which are available on the wiki
activities page (I'm not sure why). You can find .xo bundles for the
TamTam** activities here:

http://mock.laptop.org/repos/local.update1/XOS/index.html

** I believe the original TamTam activity is now considered old,
unsupported code, and has been split out into individual activities
called TamTamEdit, TamTamJam, TamTamMini, and TamTamSynthLab.

Once activities are installed, the new xo_get.py script (which
includes Bert's update-activities.py code), is very useful for keeping
all installed activities upgraded to the latest versions available.
You can download the xo-get.py file from:

http://wiki.laptop.org/go/Xo-get
</pre>

Revision as of 23:13, 1 August 2008

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