[SOLVED] [MQTT] How to send integer value to a dimmer?

[Pietvc (Piet Van Cleemput)]

I see this is an older topic but for me still actual.
I like to control the brightness of tradfri lightbulb, in OH3 and UI with MQTT.
Brughtness needs to be integer 0-255, Dimmer sends 0.00…-0.9999.
Where to put this function?
How to address this function?
How to use transformation?
Thanks in advance for some help!
Best regards
Piet

[hafniumzinc (T)]

@Pietvc

I like to control the brightness of tradfri lightbulb, in OH3 and UI with MQTT.

Maybe this might help?

[OH3] Ikea Tradfri LED1649C5 e14 dimming bulb via zigbee2mqtt

Foreword This tutorial is for openHAB3. If you are on openHAB2 you will need to use my older tutorial . We have an Ikea Tradfri e14 400lm dimmable bulb. Here is how I integrated into openHAB, via zigbee2mqtt and Mosquitto . This tutorial was written with openHAB3 running on a headless Raspberry Pi 3B with Raspberry Pi OS, with SSH access. Overview This tutorial assumes you have openHAB3 installed. This tutorial will show you how to: Install an MQTT broker, install the MQTT binding, and c…

[Pietvc (Piet Van Cleemput)]

Dear hafniumzinc, thanks, this helped a lot.
Major problem was I’ve chosen numbertype instead of percentage, and with creation of model changed number to dimmer. This resulted in publishing 0.99 when pointed to 99 on the scale from 0 to 254.==>brighness of bulb ± 1%

Still have issue: Publish 254 when pointing on 100 on the scale of 0 to 254 gives brightness of 100%.
Is there a solution to get a scale from 0% to 100% and publishing 254 when pointing to 100% ?

[hafniumzinc (T)]

@Pietvc

Still have issue: Publish 254 when pointing on 100 on the scale of 0 to 254 gives brightness of 100%.
Is there a solution to get a scale from 0% to 100% and publishing 254 when pointing to 100% ?

Did you carefully do this bit from that tutorial?

We have to make one small adjustment to the Item created for the Dimmer Channel:

Items → PorchLight_Dimmer → Add Metadata → State Description

Min: 0
Max: 100
Click Save top-right.

[Pietvc (Piet Van Cleemput)]

Dear Hafniumzinc, SOLVED !!

Thanks a lot !!

Best regards
Piet

[jonatanhov (Jonatan Hovgaard)]

What am I missing here? My problem seems to be the same. I have added the “state description” “min/max” and configured my channel as follows. Setting the dimmer to 50 in Openhab3 will only send 0,1 to MQTT

UID: mqtt:topic:cb609d2f95
label: Hue White Ambiance 1
thingTypeUID: mqtt:topic
configuration: {}
bridgeUID: mqtt:broker:e90f42a7f8
location: Kitchen Island
channels:
  - id: state
    channelTypeUID: mqtt:string
    label: state
    description: null
    configuration:
      commandTopic: zigbee2mqtt/0x001788010830795c/set/brightness
      postCommand: true
      step: 1
      min: 0
      stateTopic: zigbee2mqtt/0x001788010830795c/brightness
      max: 255

Thanks in advance

[hafniumzinc (T)]

@jonatanhov

channelTypeUID: mqtt:string

You’re using a String type Channel for a dimmer? Is that deliberate? If not, you will need to delete this Channel and create a new one - you can’t change the type of an existing Channel via the UI.

[jonatanhov (Jonatan Hovgaard)]

It was a mistake. I deleted the channels and recreated the thing/item/channel with this configuration:

  - id: state
    channelTypeUID: mqtt:switch
    label: state
    description: ""
    configuration:
      commandTopic: zigbee2mqtt/0x001788010830795c/set/state
      stateTopic: zigbee2mqtt/0x001788010830795c/state
      off: OFF
      on: ON
  - id: brightness
    channelTypeUID: mqtt:dimmer
    label: brightness
    description: ""
    configuration:
      commandTopic: zigbee2mqtt/0x001788010830795c/set/brightness
      min: 0
      stateTopic: zigbee2mqtt/0x001788010830795c/brightness
      max: 254
      off: OFF
      on: ON

Now everything works as intended

Thanks