Fade-in and fade-out

[hum6le101]

I'm currently using Ikea KAJPLATS lights and was wondering, if there was a way to have a smooth transition of the lights. Basically a fade-in over x seconds.
Thanks alot

[florianhorner]

Yes, smooth transitions with KAJPLATS are possible via Adaptive Lighting — but the configuration that works best is counterintuitive.

Which KAJPLATS variant do you have?

This matters because KAJPLATS comes in two Zigbee profiles:

Feature	KAJPLATS_RGB	KAJPLATS_CT
Color temp range	153–555 mireds	153–454 mireds
Full color (XY)	Yes	No
Effects	blink, breathe, okay, channel_change, colorloop	blink, breathe, okay, channel_change
Power-on behavior	off/on/toggle/previous	off/on/toggle/previous

Both share the same core IKEA Zigbee limitation: transitions only work on 1 attribute at a time. Send brightness + color_temp together and one snaps instantly.

Getting into Zigbee mode

KAJPLATS ships as Matter-over-Thread. To use with Zigbee2MQTT:

• 6 power cycles (off→on) = Matter/Thread factory reset (warm white flash)
• 12 power cycles = Zigbee pairing mode (cold white pulsing)
• Some models need 15 cycles + TouchLink scan

⚠️ Not all units enter Zigbee mode successfully — some firmware versions resist. Switching to Zigbee disables Thread, and no OTA firmware updates are available via Z2M for KAJPLATS.

The critical Adaptive Lighting settings

separate_turn_on_commands: true

This is essential for all IKEA bulbs. Without it, AL sends brightness and color_temp in one call, and IKEA firmware randomly applies one and ignores the other. This splits them into two sequential light.turn_on calls.

Trade-off: take_over_control breaks when combined with this (see issue #802) — manual remote adjustments go undetected.

transition: 0 (not 20, not 45)

This is the key insight most guides get wrong. During any color/color_temp transition, IKEA bulbs enter a frozen state where they silently ignore all Zigbee commands — including OFF. A 20s transition = 20s where your light switch does nothing. The AL README itself recommends transition: 0 for IKEA.

Instead, use frequent zero-transition updates to simulate smoothness:

interval: 15

With transition: 0 and interval: 15, AL pushes small instantaneous updates every 15 seconds. The result looks smooth without ever freezing the bulb.

Recommended config

adaptive_lighting:
  - name: "kajplats"
    lights:
      - light.your_kajplats_bulb
    separate_turn_on_commands: true
    send_split_delay: 1           # 1ms between split commands (sufficient for IKEA)
    transition: 0                 # avoid freeze bug entirely
    initial_transition: 1         # gentle 1s fade-in on turn-on
    interval: 15                  # frequent updates = perceived smoothness
    detect_non_ha_changes: false  # prevent false manual_control triggers
    min_brightness: 2             # avoid brightness=1 flash bug on some FW
    max_brightness: 100
    min_color_temp: 2200
    max_color_temp: 4000
    prefer_rgb_color: false       # use CT mode, not XY
    take_over_control: true

If you want slightly visible transitions and can tolerate brief unresponsiveness, transition: 4 with interval: 30 is a workable middle ground.

For longer fade-ins (e.g. wake-up)

initial_transition handles the off→on moment, but for multi-minute sunrise fades, step the brightness incrementally:

automation:
  - alias: "Morning fade-in"
    trigger:
      - platform: time
        at: "06:30:00"
    action:
      - service: light.turn_on
        target:
          entity_id: light.your_kajplats_bulb
        data:
          brightness: 3
          color_temp: 454
      - delay: "00:00:03"
      - repeat:
          count: 10
          sequence:
            - service: light.turn_on
              target:
                entity_id: light.your_kajplats_bulb
              data:
                brightness: "{{ 3 + (repeat.index * 25) }}"
            - delay: "00:01:00"

Note: do not add a transition parameter to the repeat steps — each step should be instantaneous to avoid the freeze.

Groups

Use native Zigbee groups created in Z2M, not Home Assistant light groups. This reduces command traffic and keeps bulbs synchronized despite separate_turn_on_commands splitting each adaptation into two calls.

Known KAJPLATS-specific issues

• Adding KAJPLATS in Zigbee mode has been reported to destabilize existing Zigbee meshes
• No OTA updates means firmware bugs are permanent
• Empty manufacturer/model strings can break auto-detection in ZHA and Z2M (basic support added to Z2M dev branch late Dec 2025)

Hope this helps — the TL;DR is: separate_turn_on_commands: true, transition: 0, interval: 15. Smoothness through frequency, not long transitions.