Home made hardware

One of the nice things about NetHomeServer is that it is relatively easy to build your own low cost hardware to control radio and IR devices for home automation via the speaker output of the computer. You can also receive messages via the microphone input. NetHomeServer has encoders which can encode and decode a lot of protocols over the audio channel.

To my surprise I get questions from people that have designed such interfaces. I didn't think there were so many hardware designers out there! I have now collected a few such designs that I have made and some that users has sent to me on a new hardware page. So if you are one of those who have built a nice interface to NetHomeServer (or ProtocolAnalyzer), mail me some pictures and I will publish them too on the HW pages.

New WEB GUI

The weakest spot of NetHomeServer is probably currently the GUI. The current WEB GUI works for configuration, but to be honest – it is kind of geeky (See Link).

So, I am currently working on the next generation of WEB GUI. WEB development is not one of my strong points, so the development goes painfully slow. The new GUI is more oriented towards operating the devices than configuration. There are two main views where the Items are presented, one classic “map”-view where the devices are represented on an image. The controls for each Item “pop up” as a small semi transparent window when the mouse moves over the device. See below:



The other view is a more strict portlet style view, where Items are organized after the room they are located in. See:



I intended the portlet view to be the main GUI and added the map view more for demo or show. The funny thing is that when I have tried them at home for a couple of weeks, I tend to use the map view most, it feels more natural to really point at the location than to remember what I called each lamp. The development is still very much work in progress, but now it works enough for me to try it in real use. One truth remains – GUI development is hard!

Dim Nexa to absolute level

I recently got the information that the Nexa dimmers (with learning code) can actually dim to absolute levels! This makes them useful for real in home automation when you can tell a lamp to dim to 75% for example instead of just dimming up and down in steps. The function is “hidden” in the protocol and I don’t even think their own equipment can use it! I can’t however take any credit for the discovery; it was the guys at Telldus who had figured it out. Well, I have added this support to NetHome now, so there is a new Item called NexaLCDimmer, which support dimming to four different configurable levels. It is not in the official release yet, but it is in the nightly build on the download page.

Another thing I have recently realized is that Nexa are really just rebranding this product in Sweden. Even in Sweden the same product is also sold by another company under the name “Proove”. It would be interesting to know which brand names are used in other countries. I am for example almost sure that the ELRO Home Easy-system sold in Germany is the same, it would be interesting if someone could confirm this.

Waveman support

I have now added support for Waveman devices in NetHomeServer. Waveman sell remote controlled switches which use the 433.92MHz RF band. I got a request for the support of that protocol, and he could send samples of how the protocol looked. It proved to be almost identical to Nexa, only the off-signal differs. This in now available in the nightly builds. I have added a WavemanLamp-item and encoder/decoder for the protocol.

NetHomeServer 0.9 released

Finally – NetHomeServer 0.9 is released! Most functions have been available for quite a while in the nightly builds, but I haven’t taken the time to document the stuff good enough for releasing. But now it’s done. The release notes can be found at: http://wiki.nethome.nu/doku.php/nethomeserver_release09. The highlights are: CUL-support, IR-Support with PowerMid and MAC OSX-support. There are also a lot of other new Items that are finally documented and released.

Low activity during summer… I have started using a wireless numeric keyboard as an extra remote for controlling the lamps in my living room. I use the xbindkeys-tool in Linux to catch the key presses and with that I use the NetCat-program (nc) to send commands to an UDPCommandPort in the NetHomeServer. The shell command to toggle the reading lamp at my sofa becomes:

echo "call,SofaRead,toggle" | nc -u 127.0.0.1 8005

I use UDP to avoid the overhead of setting up a TCP-connection first.

Java sampler problems

The last couple of weeks have not been very productive. I started getting feedback that the audio based reception in NetHomeServer had started to hang for some users using Windows. It seems this behavior started with one of the latest Java updates. So I have spent a couple of weeks trying to hunt down this problem. To make things worse this behavior does not occur in any of my environments (One Linux and two Windows). Fortunately I have been getting great help from Walter Krämbring and David Näslund, who have received and tested numerous versions helping me to hunt down the problem. Thanks David and thanks Walter! I think I am almost there now finding a solution, but I am not sure yet. My impression is that the Java sound system is not the most reliable part of the environment. If anyone else has seen the problem that a TargetDataLine stops working after a couple of hours or that Java refuses to open a new TargetDataLine once the old one is closed, I would be glad to hear any suggestions on how to get around those problems – my current solutions are quite ugly…