Dimwit - Smarter Dimmers

I decided to finally create a binding to control my dimmers. I like the lights in my house to slowly brighten and dim during the day. You could probably create some kind of Astro rule to do this - but I like my rules simple. So I created a binding and some simple rules.

This isn’t quite ready to share because some values are hardcoded and it should probably allow for looking up sunrise/sunset values via the Astro binding. If anyone is really interested in using this I could probably figure that part out.

Just curious to see what people think.

Library code: https://github.com/holmes/dimwit
Binding Code: https://github.com/holmes/dimwit-binding


Dimwit Binding

What is it?

Lights can be bright. Each room in my house is controlled by a dimmer. I hate having to change the
dimmer value. I need it low in the morning and high in the afternoon. And if I’m vegging out on the
couch I’d like it to be dimmer at 10PM than it was at 6PM when I turned on the lights.

In fact, wouldn’t it be amazing if the lights turned on and dimmed themselves automatically based
on the time of day, when sunset and sunrise were? And if you could control each room individually? Well
now you can - home automation to the rescue!

You can use this binding to create a Thing for each light zone in your house. Once configured, it’ll
update 2 channels (high & low) with calculated light levels.

What are these light levels? The low level is your ideal light situation for that room at any given
time. In the mornings and evening you probably want it low - in the afternoon when the sun is at it’s
peak you probably want it high. Between those times you’d like it between those values.

How does it work?

There are 3 parts to this binding. You need to set up sunrise/sunset/solarNoon, you need to configure
each zone, and you need to apply the changes via a rule.

  1. Currently this is hardcoded to look for values based on data scraped from https://sunrise-sunset.org/.
    Hooking this up to an Astro plugin probably wouldn’t be that hard, but I already had this data and didn’t
    feel like doing it.

    These files contain twilightBegin/End, sunriseBegin/End & solarNoon for my location. Fresh data is loaded
    when we cross date boundaries so your light levels automatically adjust as days get longer and shorter.

    To use this you’ve got to have these files located in /opt/sunrise/data. I should probably make that

  2. You need to configure a zone. Configuration is very easy, it’s just a json object w/ times and levels.
    The TimeFrames specify an end time. These build upon each other, so you can think of the endTime being
    from the end of the previous zone to this zone’s endTime. The low levels are the basis of what’s calculated.
    The high level is what we’d want to switch to if the light switch was tapped on again.

  "deviceId": "Nursery",
  "timeFrames": [
      "endTime": "7:00",
      "lowLevel": 1,
      "highLevel": 60
      "endTime": "solarNoon:0",
      "lowLevel": 80,
      "highLevel": 100
      "endTime": "twilightEnd:0",
      "lowLevel": 50,
      "highLevel": 80
      "endTime": "23:59",
      "lowLevel": 5,
      "highLevel": 40
  1. Finally, you need to apply the changes. If you want to auto dim the lights you just need to set the
    values when the item changes. If you have switches that handle instant notification (Homeseer) then you
    can set the light value immediately when the switch is tapped.

Sample Code


dimwit:room:family_room_levels "Family Room - Light Levels" @ "Family Room" [ 
    zoneJson="{\"deviceId\": \"FamilyRoom\", \"timeFrames\": [{\"endTime\": \"sunrise:0\", \"lowLevel\": 1, \"highLevel\": 35}, {\"endTime\": \"sunrise:60\", \"lowLevel\": 30, \"highLevel\": 60}, {\"endTime\": \"solarNoon:0\", \"lowLevel\": 60, \"highLevel\": 85}, {\"endTime\": \"twilightEnd:0\", \"lowLevel\": 30, \"highLevel\": 60}, {\"endTime\": \"23:59\", \"lowLevel\": 1, \"highLevel\": 35}]}"


Dimmer family_room_low_level "Family Room - Light Level Low" { channel="dimwit:room:family_room_levels:low"}
Dimmer family_room_high_level "Family Room - Light Level High" { channel="dimwit:room:family_room_levels:high"}
Dimmer family_room_dimmer "Family Room Dimmer Switch" <slider> (Dimmers) { channel="zwave:device:34770927:node13:switch_dimmer" }

Rules - Toggle when light is tapped

val org.eclipse.xtext.xbase.lib.Functions$Function3<DimmerItem, DimmerItem, DimmerItem, Void> newToggleLevel = [
	DimmerItem dimmer, DimmerItem lowLevel, DimmerItem highLevel |
	val Number currentLevel = dimmer.state as Number
	logInfo("RULE.TOGGLER", "{} is currently at: {}", dimmer.label, currentLevel)

	var DimmerItem lightLevel
	if (currentLevel == 0) {
		lightLevel = lowLevel
	} else if (currentLevel < lowLevel.state as Number) {
		lightLevel = lowLevel
	} else if (currentLevel < highLevel.state as Number ) {
		lightLevel = highLevel
	} else {
		lightLevel = lowLevel

	if (currentLevel != 0) {
		logInfo("RULE.TOGGLER", "Sleeping for 250ms since the light is already on")	
	logInfo("RULE.TOGGLER", "About to set {} to {}", dimmer.label, lightLevel)	

rule "Family Room Sitemap Proxy Action"
	Item family_room_dimmer received update
then {
	if (family_room_dimmer_proxy.state == ON) {
		newToggleLevel.apply(family_room_dimmer, family_room_low_level, family_room_high_level)
	} else {
} end

Rules - AutoDim

val org.eclipse.xtext.xbase.lib.Functions$Function2<DimmerItem, String, Void> newAutoDim = [
	DimmerItem dimmer, DimmerItem lowLevelItem |
	val Number currentLevel = dimmer.state as Number
	val Number lowLevel = lowLevelItem.state as Number
	logInfo("RULE.AUTODIM", "{} is currently at: {}", dimmer.label, currentLevel)

	if (currentLevel == 0) {
		return null;

	if (Math.abs(lowLevel.intValue - currentLevel.intValue) <= 2) {
		logInfo("RULE.AUTODIM", "About to set {} to {}", dimmer.label, lowLevel)	

rule "AutoDim Family Room Lights"
	Item family_room_low_level received update
then {
	newAutoDim.apply(family_room_dimmer, family_room_low_level)

Very cool. Nice work!