How to use switch for light control

Setup, Configuration and Use Items & Sitemaps
1

I have test switch with config:
items:

Switch MQTT_Test "Testing..." { mqtt="<[broker:testing/mqtt/topic:state:default], >[broker:testing/mqtt/back-topic:command:*:default]" }

sitemaps:

	Text label="MQTT_Test Sensor" icon="light" {
            Default item=MQTT_Test label="MQTT_Test"
        }

Hardware switch send “testing/mqtt/topic” message.
Hardware relay wait for “testing/mqtt/back-topic” message

From UI I able to control relay, but when I press hardware button - in UI I see ON, but no “testing/mqtt/back-topic” message.

What is right config to on/off light by button and UI?

2

Have you installed the mqtt binding?
If yes, can you post your mqtt.cfg located in your conf/services folder, please?
How do you monitor your mqtt traffic?

3

mqtt config very easy:

broker.url=tcp://192.168.0.4:1883

No any issues with mqtt. I able control relay from UI. Hardware send “testing/mqtt/topic” and I see ON in UI. When Ichange state in UI - relay on or off. But I can’t control relay via button. Button change state only in UI.
I monitor traffic with mqtt-spy, but it is no mqtt issue. The same behavior for switch on modbus.

4

So what you are saying is that when you change the switch on the OH UI, you don’t see the message testing/mqtt/back-topic:ON or OFF on mqtt spy, but the UI and the switch state changes when you publish testing/mqtt/topic:ON or OFF on mqtt-spy for testing

5

When i change switch state via OH UI i see message “testing/mqtt/back-topic” [ON|OFF]
But when my device publish “testing/mqtt/topic” - UI state changed, but OH doesn’t send “testing/mqtt/back-topic” with new state to device. So i can’t control light via button. Only via OH UI.

6

AAAHHHH. Ok.
So change the inbound binding to command instead of state:

Switch MQTT_Test "Testing..." { mqtt="<[broker:testing/mqtt/topic:command:default], >[broker:testing/mqtt/back-topic:command:*:default]" }
1 Like
7

BUT
I would recommend two items because you have 2 devices really, 1 switch and one light
so

Switch MQTT_Test_Switch "Testing Switch..." { mqtt="<[broker:testing/mqtt/topic:state:default], >[broker:testing/mqtt/back-topic:command:*:default]" }
Switch MQTT_Test_Light "Testing Light..." { mqtt=">[broker:testing/mqtt/back-topic:command:*:default]" }

And a rule:

rule "Test mqtt switch"
when
    MQTT_Test_Switch changed
then
    if (MQTT_Test_Switch.state == ON) {
        MQTT_Test_Light.sendCommand(ON)
    } else {
        MQTT_Test_Light.sendCommand(OFF)
    }
end

This way you separate the behaviours and if you wanted to command something else with that switch then you can change the rule

1 Like
8

I guess change binding to command instead state will work. Will test it today.
Config with rule works but i want to understand how to implement it without rules.
Thank, will provide feedback after testing.

9

Using the rules will give far more flexibility. Just advice