Raspberry Pi

Today my Raspberry Pi finally arrived! One of the projects I'm planning to use it for is out-of-band management for PCs.

This blog post will evolve as I'll discover interesting things to do with my RPi.

About the hardware:

Arch Linux Essentials

Here are some of the steps that are most essential for me on the Arch Linux ARM image that I put on the SD card for my RPi:

  • change root password: passwd
  • Extend the root partition to the full size of the SD card
  • updating: pacman -Syyu
  • adduser philipp
  • pacman -S sudo; edit /etc/sudoers and uncomment the %wheel line; usermod -G wheel philipp
  • gpasswd -a philipp uucp
  • pacman -S make
  • pacman -S python
  • pacman -S python-virtualenvwrapper Arch Wiki: Virtualenvwrapper
  • Assign as much RAM to the system instead of to the GPU as possible: Set gpu_mem=16 in /boot/config.txt. See this. (Previously you had to do cp /boot/arm224_start.elf /boot/start.elf. See here.)
  • Make HDMI work mv /boot/config.txt /boot/config.txt.bak
  • Change the used mirror in /etc/pacman.d/mirrorlist

Debian Essentials

  • changing the password: passwd
  • updating: sudo apt-get update && sudo apt-get upgrade
  • installing screen: sudo apt-get install screen
  • sudo apt-get install alsa-utils; sudo modprobe snd_bcm2835; sudo amixer cset numid=3 1 to be able to listen to audio via the headphone jack. See here.
  • Playing m3u playlists: mpg123 -@ http://streams.br-online.de/bayern3_2.m3u

GPIO with the RPi

A couple of resources

More Software

  • OpenCV on ALARM (see this): pacman -S python2 python2-numpy opencv opencv-samples


Webcam Streaming

Relay Card

I'm planning to use this card with my RPi: http://www.amazon.de/dp/B005WR72S4. Here is a wiring example:

Raspberry Pi Relay Module
GND (Pin 6) GND (Pin 1)
5 Volt (Pin 2) VCC (Pin 6)
GPIO0, GPIO1, GPIO4 and GPIO17 (Pin 3,5,7 and 11) IN1 to IN4 (Pin 2 to Pin5)

Raid on the RPi

A nice blog post about setting up a raid 5 using mdadm can be found here: RAID Pi – Raspberry Pi as a RAID file server. It is a bit negative about the speed of the setup (OK - I see the problems: SATA HDDs connected via USB, only 100Mbit networking, limited CPU) but if you need redundancy for your data storage, this might be worth the effort. In a comment, guillem states that he would expect a better performance for btrfs.

WiFi Access Point with the RPi

See Setting up a Raspberry Pi as a WiFi access point.