Missing AC Capabilities via Samsung MIM-H04N WiFi Kit (OCF vs Direct)

Third party integrations
1

Hello SmartThings community and protocol geeks :wave:

I need help solving what seems to be a major capability loss in a Samsung multi-split AC setup using the MIM-H04N WiFi Kit.

:gear: Setup:

  • Samsung System A/C (4 indoor units)
  • Controlled via MIM-H04N WiFi Kit
  • Connected to SmartThings Cloud (OCF-based)
  • Each indoor unit appears as a child device

:test_tube: What works:

  • Basic HVAC control (mode, setpoint, fan speed, swing, etc.)
  • Power on/off
  • execute and switch capabilities on the parent (but very limited)

:no_entry_sign: What doesn’t work (but should):

These features are 100% supported when the same AC unit is connected directly via Wi-Fi, but become unavailable when connected through the WiFi Kit:

Feature Works via native Wi-Fi? Works via WiFi Kit?
Beep sound toggle :white_check_mark: Yes (API & UI) :x: No
Display light toggle :white_check_mark: Yes (Lighting option) :x: No
Optional modes (sleep, speed, etc.) :white_check_mark: Yes :x: Some are missing
Air quality options :white_check_mark: (in capabilities) :x: Missing entirely
OCF execute options :white_check_mark: Limited :x: Most fail with NOT_FOUND

I’ve tried:

  • SmartThings API (via Postman)
  • SmartThings CLI
  • Advanced Web IDE
  • Multiple execute paths (mode/vs/0, etc.)
  • All known x.com.samsung.da.options
  • Monitoring event logs while pressing “Lighting” or “Beep” on physical IR remote → No events are captured.

Even tried polling capabilities like airConditionerLighting, audioVolume, airConditionerBeep, airConditionerOptionalMode, airConditionerFanOscillation, doNotDisturb, etc. — but none are exposed on the child devices, or on the parent.

:pushpin: Important detail:

  • The same model indoor unit, when connected without the MIM-H04N (i.e. Wi-Fi embedded), exposes all capabilities in SmartThings.
  • So it’s not a model limitation — it’s a firmware/API exposure limitation through the MIM-H04N.

:question: My questions:

  1. Is there any hidden execute command or undocumented capability that can trigger these functions?
  2. Has anyone hacked/extended functionality of the MIM-H04N via SmartThings (Edge Driver, OCF, CLI)?
  3. Is there any official roadmap or workaround from Samsung to fix this limitation?

:dart: Goal:

Enable full automation and voice control over all features already supported by the device — not just the basics.

Any insights, deep dives, or clever hacks are very welcome. :pray:
I’m happy to share my API logs, device dumps, and test cases.

Thanks in advance to anyone up for the challenge!

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