Control two openHAB items with just one Google Assistens Item

Apps & Services Google Assistant
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1

I have a dimmable light that is split into two things because the modbus implementation for this device is set this way:

AU.Sauna Licht Kabine (switch)
AU.Sauna Licht Kabine Helligkeit (dimmer)

I linked those to some items:

// Modbus
Group	g_AU_Sauna_Licht_Kabine_Wrapper		"Sauna Kabine"																				{ homekit="Lighting" }
Switch	AU_Sauna_Licht_Kabine				"Sauna Kabine"				(g_AU_Sauna_Licht_Kabine_Wrapper, g_AU_Licht, g_AU_Sauna)		{ ga="Light", alexa="PowerController.powerState" [category="LIGHT"], homekit="Lighting.OnState", autoupdate="false"}
Dimmer	AU_Sauna_Licht_Kabine_Helligkeit	"Sauna Kabine Helligkeit"	(g_AU_Sauna_Licht_Kabine_Wrapper)								{ homekit="Lighting.Brightness", autoupdate="false" }
String	AU_Sauna_Licht_Kabine_Name										(g_AU_Sauna_Licht_Kabine_Wrapper, g_Persist_Restore)			{ homekit="Lighting.Name" } // FĂŒr Homekit Binding, setzen per Konsole

My goal is to be able to control this light with one item in Google Assistant. Currently I can only turn it on / off (which makes sense of cource because I have the tag on the switch item).

For homekit I can achieve this just fine because the characteristics (on/off, dimmer level) can be set to different items in a group, but the Google Assistant binding does not seem to support something like that.

How can I control these two openHAB items with just one Google Assistent item?

2

Dimming to zero does not turn the item off?

If it does you are done, if not you need to expose two things to google assistant.

3

It does turn it off, but on the physical light switch there ist a „power on/off“ button that restores to the latest brightness. That’s the main reason I want to keep things seperated. Sorry I forgot to mention this.

So

  1. I turn it off by setting the brightness to zero
  2. I turn it on with the physical button
  3. Nothing happens, it‘s „on“ now at 0 percent brightness

There must be some fancy workaround using proxy items and/or rules but I can‘t wrap my head around that yet.

4

You might be able to use a proxy item and rule like:
Item:

Dimmer	AU_Sauna_Licht_Kabine_GA				"Sauna Kabine" { ga="Light" }

Rule:

rule "Google assistant sauna light"
when
    Item AU_Sauna_Licht_Kabine_GA received command
then
    if (receivedCommand instanceof OnOffType) {
        AU_Sauna_Licht_Kabine.sendCommand(receivedCommand)
    } else {
        AU_Sauna_Licht_Kabine_Helligkeit.sendCommand(receivedCommand)
    }
end

I haven’t tested, so might need tweaking, but something like this should work I believe.

2 Likes
5

You might be able to use the previousState extension to restore the dimmer value whenever the dimmer value is set to 0 by Google Assistant. You would use the dimmer item as your GA item, and whenever it goes to zero you have a rule set the switch item to OFF and restore the previous brightness.

Alternatively, you could have a rule that when your switch turns to ON (because you pressed the button), openHAB restores brightness to the previous state.

I like that the first rule does the work immediately, but your hardware might work better with the second rule.

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6

Thank you! I’ll try these suggestions and post my final solution here :slight_smile:

1 Like
7

Ok, I think I have it working now with the proxy approach:

Proxy item:

Dimmer		AU_Sauna_Licht_Kabine_Proxy_GA		"Sauna Kabine"																				{ ga="Light" }

Rules:

  1. Translate commands FROM Assistant TO the real items
    1b) Fix value in GA displaying 100% after “Turn on” command sent to Assistant
  2. Translate ON/OFF or brightness changes FROM real item TO Assistant

Maybe some edge cases (null items etc.) are still missing.

rule "Sauna Kabine Proxy Google Assistant - FROM proxy TO real item" // 1
when
    Item AU_Sauna_Licht_Kabine_Proxy_GA received command
then
    if (receivedCommand instanceof OnOffType) {
        AU_Sauna_Licht_Kabine.sendCommand(receivedCommand)
	} else if (receivedCommand.toString == "0") {
		AU_Sauna_Licht_Kabine.sendCommand("OFF")
	} else {
		AU_Sauna_Licht_Kabine.sendCommand("ON")
        AU_Sauna_Licht_Kabine_Helligkeit.sendCommand(receivedCommand)
    }
end

// Fix value in GA displaying 100% after "Turn on" command sent to GA
rule "Sauna Kabine Proxy Google Assistant - FROM proxy TO real item (fix)" // 1b
when
    Item AU_Sauna_Licht_Kabine_Proxy_GA received update
then
    if (AU_Sauna_Licht_Kabine.state.toString == "ON" &&
		AU_Sauna_Licht_Kabine_Proxy_GA.state.toString != AU_Sauna_Licht_Kabine_Helligkeit.state.toString) {
		if (AU_Sauna_Licht_Kabine_Helligkeit.state == NULL) {
			logWarning("Licht", "AU_Sauna_Licht_Kabine_Helligkeit NULL")
			return;
		}
		AU_Sauna_Licht_Kabine_Proxy_GA.postUpdate(AU_Sauna_Licht_Kabine_Helligkeit.state.toString)
	}
end

rule "Sauna Kabine Proxy Google Assistant - FROM real item TO proxy" // 2
when
    Item AU_Sauna_Licht_Kabine changed or
	Item AU_Sauna_Licht_Kabine_Helligkeit changed
then
	if (AU_Sauna_Licht_Kabine.state == NULL) {
		logWarning("Licht", "AU_Sauna_Licht_Kabine NULL")
		return;
	}
    if (AU_Sauna_Licht_Kabine.state.toString == "ON") {
		if (AU_Sauna_Licht_Kabine_Helligkeit.state == NULL) {
			logWarning("Licht", "AU_Sauna_Licht_Kabine_Helligkeit NULL")
			return;
		}
        AU_Sauna_Licht_Kabine_Proxy_GA.postUpdate(AU_Sauna_Licht_Kabine_Helligkeit.state.toString)
    } else {
        AU_Sauna_Licht_Kabine_Proxy_GA.postUpdate("OFF")
    }
end

So now everything is working but I needed 3 rules for it. I have a feeling that there might be a simpler approach, so if anybody knows how to simplify this I’m quite interested :slight_smile:

Thanks for your help guys!

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