I want to get into home automation by starting with a simple installation in an European home:
1. A central linux-computer should dim a set of 1-4 light bulbs time based.
2. The dimming should be very precise. As I want to have the bulbs dim over the course of one hour (!) the resolution should be good. Meaning during that time one shouldn't see the brightness "jump" from one to the next level, but rather have a smooth fading.
3. [optional] A wall mounted controller should allow to set the time of day _when_ the fade to "on" (fully bright) or "off" (no light) should be started.
Now I do not know with which hardware to start:
A) What should I use to make light bulbs controllabe?
B) What controller would you recommend?
C) Is Openremote ORB the thing to go for?
I want a state-of-the-art solution (I read that KNX is superior to X10 
). My budget is about EUR 500,- to EUR 700,-
Your suggestions are very welcome!
Please note, that this is my first contact to the issue, but I'm usally very good at learning technical things 
Regards,
Han
Comments (6)
Nov 14, 2009
Juha Lindfors says:
Start by deciding what protocol to use to control your lights. KNX is very like...Start by deciding what protocol to use to control your lights.
KNX is very likely to take you over your budget for what you're planning.
X10 seems to suffer with dimming issues when modern fluorescent light bulbs are used. You want to make sure at least that whatever X10 solution you choose, has a solution to this.
Beyond those two, I'd recommend looking into Zigbee and Z-wave which may be able to meet your requirements within your budget.
Nov 15, 2009
Jörg Falkenberg says:
I'm not sure about X10, but KNX has an 8 bit resolution for dimming. Depending o...I'm not sure about X10, but KNX has an 8 bit resolution for dimming. Depending on the type of light source and the speed of dimming, you will see jumps from one value to the next. I tried dimming LEDs with an 8 bit PWM (self-brewn, not KNX) and on the single digit brightnesses there's definitely a jump. Part of that is physiological as the eye adopts to the darkness if all lights are off. A jump from 1/256 to 2/256 is then really doubling the brightness - not much in lumen, but you will see that... That effect is worse if you dimm really slow.
Nov 15, 2009
Mathieu Gallissot says:
Hi, X10 has a 6 bit resolution dimming (64 levels) while the KNX standard dimmi...Hi,
X10 has a 6 bit resolution dimming (64 levels) while the KNX standard dimming has an 8 bit resolution (so 256 levels). Anyway, for these technologies, as Jörg said above, devices will react logarithmically (with incandescent and fluorescent). That's a tip used for energy saving, to set the maximum level at 80%, where the difference with 100% is almost non-visible.
For lighting, DALI is quite often used (in combination with KNX). But if you really want to go precise, DMX seems the best protocol.
Nov 15, 2009
Marcus Redeker says:
Technology wise everything is said Depending on what lights (halogen, normal, f...Technology wise everything is said
Depending on what lights (halogen, normal, fluorescent lamp) you want to dimm and if you want to dimm all 4 lights seperately (4 dimming channels), all 4 together (1 channel) or maybe 2 and 2, I might be able to get you the needed KNX components to get started (Power supply, USB interface, 4time binary input, dimmer).
--Marcus
Nov 15, 2009
Han Solo says:
Thanks for your very good hints. My ideas to your comments: * the lights I w...Thanks for your very good hints.
My ideas to your comments:
* the lights I want to control are energy-saving "daylight"-bulbs
* due to the low resolution X10 is not in question anymore
* I definitely want a wired solution (as opposed to zigbee / z-wave)
* thanks for the 80 % idea - it (additionally) helps use the resolution in between those values
* i'm willing to raise the budget for better quality
* controlling 2 and 2 of the bulbs would suffice, but if the price difference isn't big, i'd just as likely control 4 separately
I've read the DALI and DMX articles on wikipedia. Would they require additional wireing, or would it still be possible to use the power line?
Marcus, can you explain how the parts you mentioned would interact? which part is the power supply for?
Can some of you also name me specif part-names, so I can look them up on the internet to get a better understanding? I wasn't really able to find anything if I just typed "KNX parts" or such ...
Nov 15, 2009
Marcus Redeker says:
First, not all energy-saving lights are dimmable. You will have to check if they...First, not all energy-saving lights are dimmable. You will have to check if they are based on fluorescent technology. Some of these lamps can be dimmed using the 0-10V dimmer which are used together with the fluorescent ballast some cannot be dimmed.
You just mentioned power line. That brings in a different variable. All mentioned technologies are not based on power line. Only one manufacturer of KNX has some power line devices but my offer is based on KNX twisted pair. The KNX twisted pair technologies needs the power supply to created the bus power.