Raspberry Pi

I received a free Raspberry Pi from Simplivity for being a vExpert (Congrats to Joe and Jarret on achieving the same!) It was very nice of them. It was even the B model and not the A model… Simplivity doesn’t mess around :). After receiving the Raspberry Pi (RPi), I realized that I needed to order the following accessories to be able to use it:

  • Power Supply
  • SD flash card
  • AUX to RCA converter (since I will be using an RCA cable to connect to a TV)

I did some research and I came across this site for a supported list of Flash Cards for the RPi. Pick one from the list that suits your needs :) I wasn’t planning to put movies on the SD Card, it was going to be used for the OS. Here is a list of all the parts (and links) that I ordered for the RPi:

If you are using HDMI or just regular speakers, the last part is probably unnecessary.

Raspberry Pi and XBMC

From the get-go I wanted to use the RPi for a media center. I have used XBMC in the past and I really like it. There are actually 3 primary OSes that support running XBMC on the RPi. Here is a good site that talk about all three:

From the top link, here is a quick summary for each:

Raspbmc Raspbmc is running a full version of Linux under the hood, so it takes a little while to boot up and takes up a good chunk of your SD card. The interface feels a little sluggish compared to a lighter weight distro like OpenELEC.

Pros: Easiest to install, does a lot out of the box, lots of room for tweaking Cons: Slow

OpenELEC OpenELEC has the same main goal as Raspbmc: provide a simple media center for your Raspberry Pi. The main difference between the two is that OpenELEC doesn’t bother with a Linux distro underneath it, and the entire installation is about 100 MB (Raspbmc is about twice this). OpenELEC is built for one purpose: to be a standalone and lightweight XBMC box.

Pros: Very fast Cons: More difficult installation, not a lot of room for tweaking

XBian XBian is all about two things: constant updates and new features. Like OpenELEC, XBian is simple and small. This makes XBian fast to boot, easy to install, and easy to use. Xbian is built on top of Raspbian, the main operating system for the Raspberry Pi.

XBian also supports packaged installers where you can download entire sets of software in one click. This means you can set up something like Samba, Couch Potato, or Sick Beard easily, perfect for a mini home server

Pros: Fast, highly configurable, easy to install, gets features earlier than anyone else Cons: Possibility for bugs on the bleeding edge

XBian

At first, I decided to try Xbian since it seems pretty much in between. The install is fairly simple. Download their image from here:

xbian download OpenELEC on Raspberry Pi

I just grabbed the latest version at the time. After the download was finished, I had the following file on my laptop:

elatov@fed:~/downloads$ls -l *.7z
-rw-rw-r-- 1 elatov elatov 215575566 Oct 26 10:39 XBian_1.0_Beta_1.1.7z

Exacting the file looked like this:

elatov@fed:~/downloads$$7za x XBian_1.0_Beta_1.1.7z
7-Zip (A) [64] 9.20  Copyright (c) 1999-2010 Igor Pavlov  2010-11-18
p7zip Version 9.20 (locale=en_US.UTF-8,Utf16=on,HugeFiles=on,2 CPUs)

Processing archive: XBian_1.0_Beta_1.1.7z

Extracting  XBian_1.0_Beta_1.1.img

Everything is Ok

Size:       534773760
Compressed: 215575566

I then plugged in the Flash Card into the laptop and I saw the following in dmesg:

elatov@fed:~$ dmesg | tail -16
[ 1639.674437] mmc0: new high speed SDHC card at address e624
[ 1639.776374] mmcblk0: mmc0:e624 SU32G 29.7 GiB
[ 1639.780554] mmcblk0: error -123 sending status command, retrying
[ 1639.782592] mmcblk0: error -123 sending status command, retrying
[ 1639.784618] mmcblk0: error -123 sending status command, aborting
[ 1639.791952] ldm_validate_partition_table(): Disk read failed.
[ 1639.792111] Dev mmcblk0: unable to read RDB block 0
[ 1639.792133]  mmcblk0: unable to read partition table
[ 1639.966131] mmc0: card e624 removed
[ 1642.257850] mmc0: new high speed SDHC card at address e624
[ 1642.259458] mmcblk0: mmc0:e624 SU32G 29.7 GiB
[ 1642.266301]  mmcblk0: p1
[ 1643.751614] mmc0: card e624 removed
[ 1647.889694] mmc0: new high speed SDHC card at address e624
[ 1647.890583] mmcblk0: mmc0:e624 SU32G 29.7 GiB
[ 1647.899235]  mmcblk0: p1

So my device showed up as /dev/mmcblk0. Now for the actual install:

elatov@fed:~/downloads$ sudo dd if=XBian_1.0_Beta_1.1.img of=/dev/mmcblk0

After the install finished, I eject the SD Card from my laptop and then plugged into the RPi. BTW here is how the final RPi looked like:

Rpi great OpenELEC on Raspberry Pi

As soon as you plug in the power cord, the RPi will start to boot. As promised, the configuration was really easy. You can even SSH into xbian, run xbian-config, and it will give you an ncurses terminal UI to make some of the configuration changes:

xbian config OpenELEC on Raspberry Pi

More information on configuring Xbian can be found here

I definitely liked the ease of use of XBian. I then configured XBMC to play files from my Plex Media Server using UPNP and the playback was pretty smooth. However playing internet streams was a little choppy. When I was using my old XBMC machine, it wasn’t like that. Since I haven’t invested too much time with Xbian, I decided to try out OpenELEC.

OpenElec

The install is very similar for OpenELEC as it was for Xbian. Go the OpenELEC download page:

openelec downloads page OpenELEC on Raspberry Pi

After the download is finished, you should have the following file:

elatov@fed:~/downloads$ls -l *.tar
-rw-rw-r-- 1 elatov elatov 101253120 Oct 27 08:26 OpenELEC-RPi.arm-3.2.3.tar

Extract the archive:

elatov@fed:~/downloads$tar xf OpenELEC-RPi.arm-3.2.3.tar

The archive contains an installer which will basically create the necessary partitions and then dd the OpenELEC image onto the device that you provide as an argument to the install script. You can check what utilities are necessary for the install script by running the following:

elatov@fed:~/downloads$ cd OpenELEC-RPi.arm-3.2.3
elatov@fed:~/downloads/OpenELEC-RPi.arm-3.2.3$ grep which create_sdcard
  which parted > /dev/null
  which mkfs.vfat > /dev/null
  which mkfs.ext4 > /dev/null
  which partprobe > /dev/null
  which md5sum > /dev/null

If you have all of the above tools already installed, then run the following:

elatov@fed:~/downloads/OpenELEC-RPi.arm-3.2.3$ sudo ./create_sdcard /dev/mmcblk0

That will finish the install. After it’s done, unplug the SD Card from the laptop and then plug it into the RPi. Plug in the power and it will start to boot. After the boot up process is finished you will see the setup wizard:

openelec wizard OpenELEC on Raspberry Pi

Just follow the wizard and configure it to your fit your needs. Playing media via UPNP was smooth. Also watching internet streams was not choppy. So I was pretty happy with the OpenELEC install. After that, I customized the install with little tweaks.

Change the Skin to xTV-SAF

From XBMC go to System -> Appearance -> Skin -> Get More and install the xTV-SAF skin/theme. After it’s installed, it will look like this:

xtv saf skin enabled OpenELEC on Raspberry Pi

I use that skin since my TV has a pretty low resolution and it’a hard to see some of the options.

Change the Font for the xTV-SAF Skin

On top of installing another skin, I also ended up increasing the font to ease reading the tiny sub-options. During the initial configuration wizard, I ended up enabling ssh for OpenELEC. So I can ssh into the RPi by using the following credentials:

user: root passwd: openelec

One bad thing about OpenELEC is that you can’t change the root password, since the rootfs is mounted read-only as squashfs:

pi:~ # mount  | grep ' / '
rootfs on / type rootfs (rw)
/dev/loop0 on / type squashfs (ro,relatime)

And you can’t remount squashfs read/write on the fly. To change the password you have mount the SD card on another machine and make changes there. The process is described here. This is only for my home, so I didn’t care about that.

To change the font for the xTV-SAF skin, edit the following file:

pi:~ # vi .xbmc/addons/skin.xtv-saf/720p/Font.xml

and modify the following section:

<fontset id="XBMC Default" idloc="31577" unicode="true">
                <font>
                        <name>rss20</name>
                        <filename>arial.ttf</filename>
                        <size>36</size>
                </font>
                <font>
                        <name>font11</name>
                        <filename>arial.ttf</filename>
                        <size>36</size>
                </font>
                <font>
                        <name>font12</name>
                        <filename>arial.ttf</filename>
                        <size>36</size>
                </font>
                <font>
                        <name>font13</name>
                        <filename>arial.ttf</filename>
                        <size>36</size>
                </font>
                <font>
                        <name>font18</name>
                        <filename>arial.ttf</filename>
                        <size>36</size>
                </font>
                <font>
                        <name>font20</name>
                        <filename>arial.ttf</filename>
                        <size>36</size>
                </font>
                <font>
                        <name>font22</name>
                        <filename>arial.ttf</filename>
                        <size>38</size>
                </font>
                <font>
                        <name>font28</name>
                        <filename>arial.ttf</filename>
                        <size>48</size>
                </font>
        </fontset>

Restart OpenELEC to apply the above changes.

Enable the XBMC Webserver

Usually this is available in the regular XBMC settings, but with OpenELEC we have to edit the .xbmc/userdata/guisettings.xml file and add the following to it:

<webserver>true</webserver>
<webserverpassword>password</webserverpassword>
<webserverport>8080</webserverport>
<webserverusername>elatov</webserverusername>
<webskin>webinterface.default</webskin>

Restart OpenELEC to apply the above changes.

OpenELEC Performance Tweaks

I read a couple of sites that talked about dirty regions. More information on dirty regions can be seen here. From that page:

Enable dirty-region processing. Dirty regions are any parts of the screen that have changed since the last frame. By not re-rendering what hasn’t changed, big speed gains can be seen. Because all GPUs work differently, only Mode 3, combined with nofliptimeout=0, is guaranteed to be safe for everyone.

I also saw a couple of other posts that had similar goals:

In the end, I added the following to my .xbmc/userdata/advancedsettings.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<advancedsettings>
  <network>
    <cachemembuffersize>30242880</cachemembuffersize>
  </network>
  <fanartheight>560</fanartheight>
  <thumbsize>256</thumbsize>
  <gui>
    <algorithmdirtyregions>3</algorithmdirtyregions>
    <nofliptimeout>0</nofliptimeout>
  </gui>
  <bginfoloadermaxthreads>2</bginfoloadermaxthreads>
</advancedsettings>

So far I haven’t seen any issues, but I might have to play with the setting more to see if something changes.

Restart OpenELEC to apply the above changes.

Enable Automatic Updates

If you didn’t select Automatic update during the configuration wizard you can enable it later. Go to Add-Ons -> Programs -> OpenELEC Settings -> System and make sure “Automatic Update” is set to auto:

openelec settings OpenELEC on Raspberry Pi

Install optware on OpenELEC

I did this on the pogoplug device before, so I decided to try it out on OpenELEC. The process is very similar. First download the main ipkg package

pi:~ # mkdir -p opt/tmp
pi:~ # cd opt/tmp
pi:~/opt/tmp # wget http://ipkg.nslu2-linux.org/feeds/optware/cs08q1armel/cross/stable/ipkg-opt_0.99.163-10_arm.ipk
pi:~/opt/tmp # tar xf ipkg-opt_0.99.163-10_arm.ipk
pi:~/opt/tmp # tar xf data.tar.gz
pi:~/opt/tmp # mv opt/* ../opt/.

Our opt directory is ready, since we can’t change rootfs, we can just mount on top of /opt from the home directory. It looks like /opt has some files in it:

pi:~ # ls -R /opt
/opt:
vc

/opt/vc:
lib

So before we mount on top of /opt, let’s copy the information into our opt directory:

pi:~ # cp -r /opt/. opt/.

Now let’s mount our directory:

pi:~ # mount /storage/opt /opt
pi:~ # mount | grep opt
/dev/mmcblk0p2 on /opt type ext4 (rw,noatime,data=ordered)
pi:~ # df -h | grep opt
/dev/mmcblk0p2           29.0G    356.9M     27.2G   1% /opt

Now let’s enable the repository to download the packages from:

pi:~ # echo "src cross http://ipkg.nslu2-linux.org/feeds/optware/cs08q1armel/cross/stable" >> /opt/etc/ipkg.conf

Also let’s add /opt/bin/ to our path:

pi:~ # cat .profile
PATH=$PATH:/opt/bin

Now you can install your regular packages. First let’s make sure ipkg is working:

pi:~ # ipkg update
Downloading http://ipkg.nslu2-linux.org/feeds/optware/cs08q1armel/cross/stable/Packages
Updated list of available packages in /opt/lib/ipkg/lists/cross
Successfully terminated.

I ended installing rsync just for testing, and it worked out:

pi:~ # ipkg install rsync

If you want /opt to be automatically mounted on boot, add the following to your .config/autostart.sh file :

pi:~ # cat .config/autostart.sh
#!/bin/sh
/bin/mount /storage/opt /opt

Monitor OpenELEC with SNMP

Since I was pretty low on ram:

pi:~ # vcgencmd get_mem arm && vcgencmd get_mem gpu
arm=384M
gpu=128M

I had 384M for the OS and 128M for the GPU, and XBMC was using most of that.

I decided to monitor the RPi with SNMP and not with the zabbix agent. Although the zabbix server can query either. To install SNMP I just used optware:

pi:~ # ipkg install net-snmp
Installing net-snmp (5.4.2.1-1) to root...
Downloading http://ipkg.nslu2-linux.org/feeds/optware/cs08q1armel/cross/stable/net-snmp_5.4.2.1-1_arm.ipk
Configuring net-snmp
Successfully terminated.

If you want to change something, you can check out the configuration for SNMP here:

pi:~ # vi /opt/etc/snmpd.conf

I didn’t change anything. To start snmpd, just run the following:

pi:~ # /opt/etc/init.d/S70net-snmp

Make sure it’s running by doing the following:

pi:~ # ps -eaf | grep snmp
22705 root       0:00 /opt/sbin/snmpd -c /opt/etc/snmpd.conf

Also do a quick test query:

pi:~ # snmpwalk -v 2c -c public 127.0.0.1 system
SNMPv2-MIB::sysDescr.0 = STRING: Linux pi 3.10.16 #1 PREEMPT Thu Oct 17 10:24:10 CEST 2013 armv6l
SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.10
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (15205) 0:02:32.05
SNMPv2-MIB::sysContact.0 = STRING: "KE"
SNMPv2-MIB::sysName.0 = STRING: pi
SNMPv2-MIB::sysLocation.0 = STRING: "Home"
SNMPv2-MIB::sysORLastChange.0 = Timeticks: (3) 0:00:00.03
...
...

Then when adding the machine to Zabbix for monitoring just select SNMP as the protocol. After some time you will be able to see CPU usage and network usage:

pi cpu usage OpenELEC on Raspberry Pi

and here is the network:

pi eth0 usage OpenELEC on Raspberry Pi

If you want snmpd to be started automatically, make sure your .config/autostart.sh looks likes this:

pi:~ # cat .config/autostart.sh
#!/bin/sh
/bin/mount /storage/opt /opt
sleep 3
/opt/etc/init.d/S70net-snmp

Backup XBMC

If you want to back up XBMC (which is what OpenELEC basically consists of), then we can use the XBMC Backup add-on, it’s part of the XBMC repository. Here is a link to the add-on. From that link here are the instructions to install the add-on:

  1. Settings
  2. Add-ons
  3. Get add-ons
  4. XBMC.org Add-ons
  5. Program Add-ons
  6. XBMC Backup
  7. Install

After it’s installed go to Add-ons section:

addons enabled addons OpenELEC on Raspberry Pi

Then click on Enabled-Addons, scroll down to the XBMC Backup Addon, select it, and you should see this:

xbmc backup configure OpenELEC on Raspberry Pi

Then click on configure and you will see the following:

xbmc backup general OpenELEC on Raspberry Pi

Notice I configured it to do local backups to the /storage/backups directory. If you have a remote NFS or Samba server (you can even back up to dropbox) then you can do that:

xbmc backup browse directory OpenELEC on Raspberry Pi

You can also choose what to back up and setup a schedule for your backups. After we are done with the configuration we can do a manual back up. From the main screen go to Add-Ons -> Programs:

xbmc program OpenELEC on Raspberry Pi

Select XBMC Backup:

xbmc backup manual backup OpenELEC on Raspberry Pi

Then select Backup and you should see the backup start:

xbmc backup manual backup going OpenELEC on Raspberry Pi

After the backup is finished you should see the backup in the folder that we set:

pi:~ # du -h backups/ -d 1
68.2M   backups/20131116
68.2M   backups/

That looks good. Now we can setup a cron job to rsync the data off to our back up server. To create the cron job, just run the following:

pi:~ # crontab -e

and a nano window will pop up, at which point you can enter the following:

crontab openelec OpenELEC on Raspberry Pi

After you done with you configurations, save and close the file. So I will backup to the remote server every month on the 2nd day of the month. You can confirm your crontab is in place by running the following:

pi:~ # crontab -l
30 3 2 * * /opt/bin/rsync -azq backups/. 192.168.1.104:/backups/pi/.

Install the Rsync Add-on

If you won’t want to mess with optware but still want rsync on OpenELEC you can use the unofficial repository to install the rsync add-on (which basically installs the rsync binary in a weird location). First download the zip for the repository from here:

openelec unoff repo OpenELEC on Raspberry Pi

After you have the zip, scp it over to the RPi:

elatov@fed:~/downloads$scp repository.unofficial.addon.pro-3.0.0.zip pi:

Now to install zip, go to Add-ons -> Install from Zip:

xbmc addon install from zip OpenELEC on Raspberry Pi

Then browse to your home directory and select the zip archive:

select unof repo zip OpenELEC on Raspberry Pi

After it’s installed you should see the following:

unof repo enabled OpenELEC on Raspberry Pi

That should enable the Unofficial OpenELEC Repository. Next let’s install rsync from that repository. Go to Add-ons -> Get Add-ons:

addon screen get addons OpenELEC on Raspberry Pi

Then select the Unofficial OpenELEC Repository:

select unof repo for addons OpenELEC on Raspberry Pi

Then select Program Add-ons:

program addons from unof repo OpenELEC on Raspberry Pi

and then select rsync:

select rsync plugin from unof repo OpenELEC on Raspberry Pi

After it’s installed you should see the following:

rsync plugin installed OpenELEC on Raspberry Pi

For some reason initially the rsync binary was not executable for me:

pi:~ # rsync
-sh: rsync: Permission denied

Maybe I need to restart OpenELEC, but I just ended up manually changing the permissions on it. First find the binary:

pi:~ # type rsync
rsync is a tracked alias for /storage/.xbmc/addons/network.backup.rsync/bin/rsync

Then make that executable:

pi:~ # chmod +x /storage/.xbmc/addons/network.backup.rsync/bin/rsync

After that I was able to use rsync. In your crontab entry use the above path if you are rsyncing backups from the above setup.

OpenELEC Information

The GUI has most of the information. If you go to System -> System Info, here is what is seen under the General section:

xbmc general settings OpenELEC on Raspberry Pi

Here is the Hardware information:

xbmc hardware info OpenELEC on Raspberry Pi

You can get most of the information from the command line as well. Here are two commands that can show you the temperature:

pi:~ # vcgencmd measure_temp
temp=50.8'C

pi:~ # sensors
bcm2835_thermal-virtual-0
Adapter: Virtual device
temp1:        +50.8 C

I was actually surprised to see the sensors module working. You can also check what codecs are enabled like so:

pi:~ # for codec in H264 MPG2 WVC1 MPG4 MJPG WMV9 ; do echo -e "$codec:\t$(vcgen
cmd codec_enabled $codec)" ;done
H264:   H264=enabled
MPG2:   MPG2=disabled
WVC1:   WVC1=disabled
MPG4:   MPG4=enabled
MJPG:   MJPG=enabled
WMV9:   WMV9=disabled

You can check the current resolution with the following command:

pi:~ # tvservice -s
state 0x40001 [NTSC 4:3], 720x480 @ 60Hz, interlaced

Published by Karim Elatov

19 November 2013

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