KNX with serial interface

[iwow]

Hallo,

first I would like to say thanks to Kai for this great project.

I have made changes in KNX bundle / KNXConnection class to use a
serial interface instead of an IP gateway.

a) Add CalimeroRXTXAdapter.jar
b) Change Member link to KNXNetworkLink (instead of KNXNetworkLinkIP)
c) Read knx:port from config (if knx:ip is null)
d) Add optional import Requirement (gnu.io) to MANIFEST.MF
e) Add gnu.io to export list in serial-binding bundle
e) Create an KNXNetworkLinkFT12 instead of KNXNetworkLinkIP if knx:ip
is null and knx:port is not null

I would like to contribute these changes. How can I provide my
changes?

Has anybody run openHAB on a Linux based embedded device? I can start
openHAB runtime on my Seagate Dockstar (1 GHz ARM CPU with 128 MB RAM
running PlugApps Linux). To optimize memory consumption I would like
to remove all optional plug-ins from the runtime (e.g. the web
application). Are the openHAB plug-ins optimal split into runtime and
designtime?

Thanks in advance

Wolfgang

[teichsta]

Hi Wolfgang,

> I have made changes in KNX bundle / KNXConnection class to use a
> serial interface instead of an IP gateway.

good to know :-)

> I would like to contribute these changes. How can I provide my
> changes?

you could clone the repository (here: http://code.google.com/p/openhab/source/checkout)
and check in your changes. After that we will do a review and merge
the changes to the default branch.

Regards,

Thomas E.-E.

[Kai Kreuzer]

Hi Wolfgang,

Cool, thanks, that sounds like a very useful extension to the KNX binding!

> I would like to contribute these changes. How can I provide my
> changes?

On the openHAB homepage, you can go to Source->Clones and create your own clone into which you can then push your commits.
I can then easily pull these changes into the main repo after a review. Let me know, if you need any further assistence.

> Has anybody run openHAB on a Linux based embedded device?

No, I haven't tried this yet, I am running it on an Atom netbook so far.

> I can start
> openHAB runtime on my Seagate Dockstar (1 GHz ARM CPU with 128 MB RAM
> running PlugApps Linux).

What JVM are you running on this? I was reluctant with embedded devices so far, because openHAB code currently requires a Java5-compatible JVM and to get such a JVM for a plug computer is often an issue...

> To optimize memory consumption I would like
> to remove all optional plug-ins from the runtime (e.g. the web
> application). Are the openHAB plug-ins optimal split into runtime and
> designtime?

I'm afraid yes. The runtime only contains the bundles that are relevant at runtime. Unfortunately, Drools is pulling in quite many dependencies, which blows up the overall size. I am actually considering some other (alternative) rule mechanism for openHAB, which could be leaner and more performant for embedded devices.

I would be very interested in your experience with this set-up as running openHAB on some existing NAS, router or plug computer is definitely an important use case.

Cheers,
Kai

[iwow]

Hi Thomas, hi Kai

I have created a new clone (mailings-openhab-clone) and pushed my
changes. It takes a little bit longer because I am not familiar with
Mercurial (it is now my fourth SCM). Please, let me know if I done
something wrong.

I am now on vacation till Easter. Kay, I answer you questions later.

Cheers,

Wolfgang

[iwow]

Hallo Kay,

> What JVM are you running on this? I was reluctant with embedded devices so far, because openHAB code currently requires a Java5-compatible JVM and to get such a JVM for a plug computer is often an issue...

I tried several JVMs over the last two years on different platforms.

a) OpenWRT with JamVM, SableVM, SUN PhoneME Advanced and cacaovm
b) PlugApps Linux with JamVM

All VMs can run a "Hallo World" example but with more complex
programms I always have problems (e.g. I use a special OSGI framework
for embedded Systems named "concierge").

Since autumn last year I have used a special JVM from the openJDK
project (http://today.java.net/pub/a/today/2009/05/21/zero-and-shark-
openjdk-port.html). Since last month a precompiled package for
PlugApps Linux exists.

> I would be very interested in your experience with this set-up as running openHAB on some existing NAS, router or plug computer is definitely an important use case.

I start to split the openHAB runtime feature into serveral functional
independent features (remove web plug-ins reduce the plug-in count
from 113 to 90)

Cheers,

Wolfgang

[Kai Kreuzer]

Hi Wolfgang,

> I tried several JVMs over the last two years on different platforms.

> [...]

Wow, you seem to be a real embedded JVM expert then :-)

> All VMs can run a "Hallo World" example but with more complex
> programms I always have problems (e.g. I use a special OSGI framework
> for embedded Systems named "concierge").

Did you see the other discussion thread about JamVM? It looks as if we are almost there getting openHAB working on it...
From your experience, do you think this is a false impression and we are heading for many further obstacles?

> I start to split the openHAB runtime feature into serveral functional
> independent features (remove web plug-ins reduce the plug-in count
> from 113 to 90)

Does this mean you use openHAB without the UI bundle? So yes, agreed, for different use cases on embedded devices it makes sense to strip down the distribution to smaller sets of required bundles.
I didn't yet want to break it into too many pieces as long as there is no comfortable provisioning for openHAB components in place - but this will come...

Regards,
Kai

[Kai]

Hi Wolfgang,

I have just added the FT1.2 support to the KNX binding. As I don't
have a serial interface available for testing right now, may I ask you
to do a brief test?

Cheers,
Kai