Cron Jobs with Mac OSX

Although launchd is the preferred method of scheduling jobs with Mac OSX, the good old cron job is easier to configure and still works:

Press i to go into vim’s insert mode.
Add a shebang if you want to run the jobs with you favorite shell:
enter your cron job e.g.
0 0 * * * brew update && brew upgrade
where 0 0 * * * stands for minute, hour, day, month, weekday
Press esc to exit vim’s insert mode
type ZZ ( in capital letters )
Verify by using

If a cron job fails, you will get a system mail.

UART on Pandaboard

List your users group with:

Add the user to the dialout group if necessary, to fix permission issues:

Now you can access all your uart devices:

for example UART4 on expansion connector A:

I2C on Pandaboard

To load the kernel module automatically at boot:

add i2c-dev

Finally add your user to the i2c group to fix permission problems:

FritzBox zu Mitternacht neu starten


Wer wie ich unter Verbindungsproblemen seiner FritzBox und UMTS leidet, kann versuchen sie jede Nacht neu zu starten. Folgenden Abschnitt einfach per nvi in die debug.cfg einfügen:

nvi /var/flash/debug.cfg

Neuer Tag, neues Glück!

Dual Boot Ubuntu 14.04 LTS on Macbook Pro with Filevault 2

Although, I prefer working on Mac OSX or using a virtual machine for all my Linux needs, sometimes that just won’t cut it. Especially when working with ROS, a native Ubuntu can help.

Shrink some partition to make space in Mac Disk Utility
Download refind 0.8.1 and unzip
Install refind into the Recovery Partition

Mount the EFI partition and edit refind.conf. Uncomment the line with dont_scan_volumes but leave the parameters empty, otherwise refind wont find your original OSX boot Partition:

If something doesn’t work, don’t worry, you can still boot OSX by holding the option key at startup.

Now follow these instructions to create a bootable Ubuntu USB Stick. Load it with the refind bootloader and select „Try Ubuntu“. Open a terminal and start the installation without boot-loader:

In the installer choose installation type „Something else“, select the free space created at step one, format as ext4 and mount at /.

Now you should have a working dual boot configuration.

Write Linaro Image to SD Card with Mac

Download the Linaro image from: here and unpack it.
Then find the disk number of your sd card, unmount and flash it:

Fhem auf Radxa Rock installieren

Der Fhem Server ist nun zum Beispiel erreichbar unter:

Gleich mal ein:

und schon ist man auf dem neuesten Stand und kann die Geschwindigkeit des Rock voll auskosten.

Jetzt noch ein altes Backup importieren:

Install ROS Indigo Igloo on Radxa Rock

Assuming you followed my tutorial for configuring your Radxa Rock, you can easily install ROS Indigo on it by:

Setup your environment:

As ROS does not recognize Linaro as an OS:

and replace „Linaro“ with „Ubuntu“

Init a catkin workspace:

and test it: