This post is just to remind me later of few misc openwrt wireless commands.
 
First there is no iwconfig you need to install it:
opkg update
opkg install wireless-tools
 
iwconfig command shows current wireless power outpu:
# iwconfig
wlan0 IEEE 802.11bgn Mode:Master Tx-Power=20 dBm
 
Maximal power is defined by multiple capability of your hardware and by laws in your country (regulatory domain).
 
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Raspberry Pi crew released tools and drivers than enabled reading from CPU and GPU temperature sensors.
 
In order to read GPU temperature use:
$ /opt/vc/bin/vcgencmd measure_temp
$ temp=43.3′C
 
Reading CPU temperature is similar, just read value from sys file system:
$ cat /sys/class/thermal/thermal_zone0/temp
$ 43850
 
As you can see both outputs need additional formatting to get only number values from them, and if you wish to have decimal precision then it gets a bit more complicated…
 
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If you have Arduino Mega 2560 on any updated Linux distro with avr-libc 1.8 you probably have an issue with compiling.
 
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I gathered all my flash based memory devices (USB flash memory sticks and SHDC cards) and wanted to see how do they compare to each other.
 

Quick google search revealed that dd tool could be used for benchmarking so that is what I used. Have you done benchamrs some other way? Please share your method.
 

Be really, really careful if you choose do to write test, because that will ERASE your existing data so test write speed only on EMPTY flash memory devices. Also triple check which device is your flash memory device. Simple typo could render your data partition unusable!
 

I didn’t want to write on the first 1GB of flash memory because that part is probably most often used, I know there are some wear-leveling chips that should take care of that but you can use skip parameter if you wish to be safe. To prefent mesuring your cache performance but actual device performance use iflag and oflag options. 
 

read speed benchmark:

$ sudo dd if=/dev/sdX1 of=/dev/zero bs=1M count=400 iflag=direct

write speed benchmark :

$ sudo dd if=/dev/zero of=/dev/sdX1 bs=1M count=400 skip=1000 oflag=direct

 
If you are running Fedora 16 or 17 and you are missing your old GNOME desktop with Compiz Fusion effects then you will love this post.
 
Thanks to the great work of Wolfgang Ulbrich for his awesome work on packaging MATE Dekstop for Fedora 16/17 and even bringing it to Fedora 18 by default!
 
Installing MATE desktop is very easy on both Fedora 16 or 17, but installing Compiz Fusion on Fedora 16 is a bit tricky.
 
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One simple oneliner that I picked up few years ago, and it is great for finding directories that eat up most of space in current directory.
 
ls -A | grep -v -e '^\.\.$' |xargs -i du -ks {} |sort -rn |head -11 | awk '{print $2}' | xargs -i du -hs {}
 

 
TrueCrypt is free (as in beer) software used for on-the-fly encryption of data, but it is not licenced under open source licence.
tc-play is free (as in freedom) tool whic provides full support for creating and opening/mapping TrueCrypt-compatible volumes and it is licenced under GPL licence.
 
Because TrueCrypt software is under a poor license, which is not only non-free, but has the potential to be actively dangerous to end users or distributors who agree to it, opening them to possible legal action even if they abide by all of the licensing terms, depending on the intent of the upstream copyright holder. Fedora continues to make efforts to try to work with the TrueCrypt upstream to fix all of the issues in their license so that it can be considered Free, but have not yet been successful. – taken from Fedora Forbidden Items page.
 
There has been no articles regarding tc-play, and that seams strange since it provides great functionality, hopefully some reviews and tutorials will soon follow.
 

 
If you wish to deploy lm-sensors on multiple diferent linux machines issue is with sensors-detect what ask you quite a few questions.
 
I asked on IRC and got few suggestions. First one is if you wish to accept defaults which sensors-detect suggest you need just to press [ENTER] all the time. To automate this use this one liner:
 
(while :; do echo ""; done ) | sensors-detect
 
If you wish to override defaults and answer YES to all questions then use this oneliner:
 
yes "" | sensors-detect
 

 
Hi, we have been testing what is the absolute maximum speed over wifi when using openwrt, for out test we used this hardware:
 
- 2 x Ubiquity Router station
- 2 x Wistron CM9 802.11a/b/g mini pci cards
- 2 x 3dBi omni antennas
 
- openwrt version – backfire 10.03.1
- wifi driver – madwifi
- distance – 2 meters (same room)
- encryption – psk2
 
For benchmarking we installed iperf package and used default settings (tcp packets in one direction).
 
First we tested “plain” 802.11a mode (hwmode 11a) on channel 40 and we got 30-35Mbit speeds.
 
Then we switched to 801.11a turbo (hwmode 11ast) and got 55-60 Mbit speeds.
 
Is this the maximum speed possible? Are there any other tweaks we can do to get faster speeds?
 
Did you get faster speeds? How? Which gear did you use? We didn’t make results artificially better by using udp packags, my guess by using udp packages we could get near 100 Mbit speeds.
 
Are there any openwrt tutorials for tweaking and benchmarking maximum speed?
 

 
Google has disabled wireless ad-hoc networking in Android from day one. Underlying Android libraries and wifi stack support adhoc networking and so far Google has provided no explanation why it still, even after four years, leaves adhoc disabled.
 
There has been huge outcry from Android users over this issue, but there is still no answer from Google Android developers.
 
There are few suggestons on xda-developers forum, and also on Stackoverflow, but most solution so far consisted of using new rom that had ad-hoc support enabled or manually messing about system config files.
 
But wait, there is an app for that!
 
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