[RaspPi] Really poor mans DS18B20 Temperature Sensor

As I had to quickly come up with two DS18B20 Sensors for the Raspberry Pi, I decided to built them "quick and dirty" without any breadboard. It is not the most beautiful nor the best way, but it works out quite well. With one exception: It seems like the sensor is too near to the Pi and picks up heat from it :/. Anyway, here are some photos:

2014-03-24 15.22.32
That is how it would look like later.

2014-03-24 15.26.00
Adding some female header to the base. We need 5 Pins for that. The first pin is going to be connected to 3,3V, the fourth to the GPIO Pin 4 and the fifth to ground. So just cut the pins 2 and 3 from that header.

2014-03-24 15.26.21
Add an resistor to pull the Data Pin high to 3,3V. You should use an 4,7k Ohm, but anything between 4,7k - 10k Ohm should work out. I used an 10k Ohm here.

2014-03-24 15.27.08
Solder the two pins of the resistor to Pin 1 and Pin 4. Do NOT short with Pin 5!

2014-03-24 15.27.48
Add some silver wire to the fifth Pin.

2014-03-24 15.31.24
Solder the DS18B20 to the Pins. Watch out for the curved side of the Sensor, it has to face upwards!

2014-03-25 07.49.59
I choose to secure the whole sensor against short circuits and stuff with hot glue. Looks ugly, but does the trick.

2014-03-25 07.50.28
Last thing is installing the sensor in the left upper corner of the GPIO Pins of your Raspberry Pi.

After booting you have to activate the One Wire protocol like this:
sudo modprobe w1-gpio
sudo modprobe w1-therm

Then you can read your sensor by using this command:
cat /sys/bus/w1/devices/28*/w1_slave

If you want to get your reading nicely formatted, you should install bc with
sudo apt-get install bc

and use this code:
echo "`cat /sys/bus/w1/devices/28*/w1_slave | grep t | cut -d= -f2`/1000" | bc -l | awk '{printf "%.2f \n", $1}'

[RaspPi] OpenWRT Trunk with latest Raspberry Pi 3.10.32+ #648 Kernel – as Image download

As a lot of people asked for the OpenWRT / Raspberry Pi Images, I decided to make a new version which replaces the old one from this post ([RaspPi] OpenWRT Trunk with latest Raspberry Pi 3.10.18+ #585 Kernel – as Image download).

That said, the rules haven't changed:
- It is the trunk version of OpenWRT, injected with the latest Raspberry Pi Kernel
- opkg list does contain the current stable package list for the OpenWRT RPi port of the latest stable release and will work out of the box (opkg update, opkg install..) Most packages like apache should work out of the box – but kernel moduls could/will probably fail. I won’t build an package mirror and won’t build packages because of limitied time. Sorry!
- Other than the normal behavior, the RPi does use DHCP to get its IP Adress. To connect for the first time, use nmap to find your RPi in your network. (Then connect via telnet, set an password with passwd and you’re good to use SSH finally!)
- The main partition size has been changed from 48 MB to 64 MB – giving you additional space

You can just download and use the (7zip-ed) image here: rpi_openwrt_2.7z [ 6.1 MB ]

I WON'T BUILD PACKAGES!
This is for the fact that I neither got enough time, nor CPU power at hand.
Sorry :(!

[Security] BetterCrypto.org - Applied Crypto Hardening

So, now something a little bit more personal: We all know about the problems in our modern world: NSA, espionage, data stealing / selling, and such. We all use computer systems on an daily base and we know about the importance of cryptography. BUT: We don't really all have an masters degree in computer crypto or such. We all do things in a "well, should be quite right"-way. Because, well - we have a life and a lot of stuff to do. We can't really tell apart which ciffer to use and such. But now - we don't need to - anymore. Please visit https://bettercrypto.org/ and read their paper. It got excellent "Copy 'n Paste" configuration commands for your Apache, Postfix, Mail, etc, etc!

Let's make the world an better and more secure place. For us and all our users!

Thanks :)!

[Ubuntu 12.04] Resolve Grub Boot Problems

If you killed your trusty grub (i.e. by new Install of Windows 8.. :/) you can repair it quite easily:
- Boot with an Ubuntu 12.04 Live CD
- CTRL + ALT + T
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair

And click on the repair button! Done!

Source: http://askubuntu.com/questions/333483/how-to-restore-grub-after-deleting-it-from-windows-8-disk-manager

[Win8.1] EEE PC 1015PN and Windows 8.1

Very funny coincidence: Exactly one year after my devastating test of Windows 8 on the EEE PC 1015PN ( here) I tried Windows 8 again - 8.1 to be frankly.

After booting from the DVD, I entered my Key and choose to keep my data and such - an Upgrade Installation. Sadly, installer told me that I needed to choose that after booting into Windows 7 and starting the installation process there. Well, I did. But I only could choose to keep my data - not my programs(!). Sad, but - well. So - if you want to install and keep your stuff: Try to install Windows 8 first and then upgrade to Windows 8.1! I made an backup (just in any case - last time showed me the importance again...) and started with the installation. I took quite a while, but in the end it succeded. This time (and maybe because I changed my Wifi/Bluetooth Card from Azure for an Intel ABGN/WiMax Card?!) - I got none problems with Wifi. Working excellent from the first moment on.

I even got Optimus working by following my own tutorial here, by using the mentioned Versions.

Concerning other drivers and tools: I installed successfully the Optimus Tool, Capshook Driver - all by using the Windows 7 Compability Mode. ( I needed to use that as well on the Optimus Driver installation!)
Regarding - especially - the AHCI Drivers (Hotkey Service) and the SuperHybridEngine Tool - well: First of them gives REAL problems. It won't work and always remind to install an working AHCI Driver. Luckily, some guys found out an way to change that: Just install these tools from an newer ASUS EEE PC - the Asus 1225B. And that does work! Link: Source, Drivers - Good thing: Without the blocking AHCI Drivers Optimus does work correctly. But fixing ACPI is not enough. You need to setup the right Touchpad Driver!

About the Touchpad? Well - you need another Hack for Windows 8: Go with these. I chose the Elantech Touchpad driver Version v.10.6.6.0.

What I really changed? Well I did some normal stuff like disabeling the User Rights Control Thingy - as well as I changed the Resolution of the Display with this little hack. That got the Metro Apps working and my display from 1024x600 to 1152x864. Ok, it is not very crispy - but really gives more usability. ( Just watch for the "Display1_DownScalingSupported" setting in the registry and enable it )

To get back your classic Start Menu Button - use: http://www.classicshell.net/

Ok, that was a lot of stuff and I am curious to see how Windows 8.1 will perform in "real life". Well, I am off to installing some more tools and such.

Android Failed to Build Eclipse Android Project Fix

[2013-11-02 08:26:51 - SearchViewDemo] Dx
trouble writing output: already prepared
[2013-11-02 08:26:51 - Dex Loader] Unable to execute dex: java.nio.BufferOverflowException. Check the Eclipse log for stack trace.
[2013-11-02 08:26:51 - SearchViewDemo] Conversion to Dalvik format failed: Unable to execute dex: java.nio.BufferOverflowException. Check the Eclipse log for stack trace.

Well that happend to me as I tried to build my latest project.
Solution was quite simple but... strange.
Just remove all newer Android SDK build-tools (i.e. 19) until the Version 18.1.1 with the Android SDK Manager.
Restart Eclipse. And it will work.

If not, try to add the Support Libraries (Right click on your Android Project in Eclipse, choose Android Tools, Add Support Library)

Issue and solutions found here: https://code.google.com/p/android/issues/detail?id=61710

[RaspPi] OpenWRT Trunk with latest Raspberry Pi 3.10.18+ #585 Kernel - as Image download

THIS POST IS OUTDATED! A NEW IMAGE HAS BEEN POSTED! PLEASE USE THE SEARCH FUNCTION TO FIND THE LATEST VERSION!

As I found out that the old tutorials weren't helpful and either the OpenWRT Trunk OR the Raspberry Pi Kernel broke the build process (you can still build it successfully, but you won't be able to use the RPi after boot!) - I sat down and found an new way. This time I don't let the kernel build by the OpenWRT enviroment, but insert an healthy and prebuilt one by the RPi Team ;)!

You can just download and use the (7zip-ed) image here: rpi_openwrt.7z [ 6.1 MB ]

There are several changes to the normal version:
- opkg list does contain the current stable package list for the OpenWRT RPi port of the latest stable release and will work out of the box (opkg update, opkg install..) Most packages like apache should work out of the box - but kernel moduls could/will probably fail. I won't build an package mirror and won't build packages because of limitied time. Sorry!
- Other than the normal behavior, the RPi does use DHCP to get its IP Adress. To connect for the first time, use nmap to find your RPi in your network. (Then connect via telnet, set an password with passwd and you're good to use SSH finally!)
- The main partition size has been changed from 48 MB to 64 MB - giving you additional space

All the best,

Nico