Ambilight anyone?


Hi there,

Has anyone ever thought of using a ledborg to achieve ambilight-like efects in RaspBMC?


piborg's picture

Boblight is a system for Linux intended for such a purpose via the boblight-v4l module (RaspBMC should provide a Boblight addon).
As for LedBorg support, we posted an example of an LedBorg module for Boblight as LedBorg-Bob, hopefully that is what you are after.

That means all I have to do is to download/configure LedBorg-Bob on my RaspBMC setup.
Is it fast/light enough that playing a movie will still be as smooth?

piborg's picture

It should be very minimal CPU load, hopefully it will not affect video playing in the slightest.

I tried that but I am experiencing problems compiling boblight, make tells me it fails to find x11. Where could I get some help?

Here’s a more accurate descreption of my attempts to get it to work:

Following the instructions found in I built ledborg-bob.
I then activated the boblight module in RaspBMC. My understsanding was that activating this module actually installed boblight.
I then tried to launch boblightd (sudo boblightd &) which couldn’t be found.
So I tried to build boblight, which fails at the configure step, telling me there’s a missing dependancy related to X11.
Now I’m wondering if boblight really was installed by activating the raspbmc module. If yes, why is it I couldn’t launch boblightd? And where is it supposed to be? Does raspbmc launch it on startup?

piborg's picture

Boblight comes in two parts, a client and a server.

The client is the part provided by the RaspBMC module, it is responsible for telling the server what colour to display.

The server is the part you are trying to build (boblightd), it is responsible for telling the hardware (via ledborg-bob in this case) what colour to display.

I have re-read the boblight compilation instructions and my guess is you need to install some pre-requisite packages before trying to build boblight, try the following alternate instructions for installing boblight:

sudo apt-get install -y libx11-dev libgl1-mesa-dev libxrender-dev libxext-dev
sudo apt-get install -y portaudio19-dev libavcodec-dev libavformat-dev libswscale-dev libavdevice-dev
sudo apt-get install -y subversion gcc g++ make libusb-1.0-0-dev unzip
cd ~
svn checkout boblight
cd boblight
sudo make install
sudo ldconfig

Followed by the second section of ledborg-bob install instructions

Full boblight build instructions can be found here
Someone else did mention having RaspBMC working successfully, unfortunately I cannot remember who it was (I will try and find out if they had to do anything special to make it all work).

Now boblight compiles, boblightd starts but:
xmbc Boblight module says it can't connect, even in remote boblight mode pointing to
boblight-constant connects, says hello then does nothing - I had to sigterm it.

piborg's picture

Glad to hear you are making progress.
Could you run boblightd from a terminal and post the output?

Opening /etc/boblight. conf
Config lines valid
Building config
Built config successfully
Starting devices
Starting with output "ledborg-bob"
Setting up
Setup succéder

Then when I start boblight-constant:

Said hello
Priority set to 128
Connection tout boblight opened

Then nothing happens anymore

piborg's picture

Have you tried putting in boblight-constant FFFFFF - does it go white?
If it doesn't work, can you set LedBorg directly to white by echo "222" > /dev/ledborg

First command does nothing, second one returns "permission denied"

piborg's picture

Permission denied sounds like a problem with the LedBorg driver rather then Boblight
Does sudo echo "222" > /dev/ledborg work?
Which version of the LedBorg install did you download?

How do I find the exact version? I just followed the instructions listed in your earlier link.

piborg's picture

To be clear I meant which version of the LedBorg driver have you installed from

I followed the shell commands provided i.e

wget -O

piborg's picture

The problem is the LedBorg driver itself also needs to be installed.
LedBorg-Bob just connects Boblight to the LedBorg driver.

The led turned green after install, but nothing changed :
Sudo echo "222" > /dev/ledborg still returns "permission denied"

piborg's picture

Sorry about the delay getting back to you, we have been rather swamped the past couple of days.

I think the problem here is that we have not made a full driver for RaspBMC, partly due to the auto-updating feature, which makes providing a binary which will work after an update problematic.

As a temporary solution I have made a modified version of LedBorg-Bob which does not rely on the driver, however it only provides 7 colours plus off as per the basic driver in the RaspBMC build.

To try this run the following:

mkdir ~/ledborg-bob-basic
cd ~/ledborg-bob-basic
sudo cp ledborg-bob /usr/local/bin/
sudo cp boblight.conf /etc/

Now restart the Raspberry Pi and start BobLight
Now try setting the colour using BobLight (I tested with boblight-constant FFFFFF, which should give white)

I shall try and get the full driver working at a later date when I am less busy.

Hi there,

I heard from RaspBMC that "kernel headers have now been included". Does it make it easier for you to build a full-blown ledbrg-bob?

piborg's picture

I'm afraid not.
Whilst the headers themselves are there (found at /lib/modules/3.6.11/build/include) , the rest of the build system appears to still be missing.

If you enter ls -a /lib/modules/3.6.11/build you will see only the include folder exists:

.  ..  include

However if I do the same thing on a system with the full build tree you see something like the following:

.            COPYING        fs          Kconfig      .missing-syscalls.d  samples        usr
..           CREDITS        .gitignore  kernel       mm                   scripts        virt
arch         crypto         include     lib          Module.symvers       security
block        Documentation  init        .mailmap     net                  sound
.config      drivers        ipc         MAINTAINERS  README               .tmp_versions
.config.old  firmware       Kbuild      Makefile     REPORTING-BUGS       tools

in particular Makefile contains the instructions to build a correct kernel module, and could be lifted from another distribution, but Module.symvers is also required and unique to the actual kernel binary, it must match for the built module to be seen as compatible.

Most of those files should be available from downloading the kernel source itself, but you would either have to find the correct Module.symvers for the build you are running, or build the kernel yourself, which would in turn generate the Module.symvers file.

I hope this clarifies the issue somewhat.

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