KNX Scene Trigger Not Firing When Scene Started from Homey Device

[stefangroenew]

Flows triggered by KNX scenes only activate when the scene is started from the KNX bus (e.g., via a KNX wall switch).
When the same scene is started from the Homey device itself, the flow does not trigger.

Expected behavior:

Triggering a scene from Homey should also fire the same KNX event (or equivalent) so that flows respond consistently, regardless of whether the scene was started from the KNX bus or from Homey.

Steps to reproduce:

• Create a KNX scene in ETS.
• Add the scene to Homey as a KNX device.
• Create a flow that triggers when the KNX scene starts.

Start the scene from:

• KNX wall switch → ✅ Flow triggers
• Homey device tile → ❌ Flow does not trigger

Observed behavior:

The flow trigger only listens to incoming KNX bus events.
Starting the scene from Homey does not generate a bus event, so the flow never runs.

[stefangroenew]

Possible implementation direction?

Root cause:

Flow trigger for “scene started” only fires on incoming KNX bus telegrams.
When a scene is started from Homey, the KNX write is sent but no trigger is emitted.

Suggested fix:

Emit the same FlowCardTriggerDevice after sending the KNX scene telegram locally, so both local and bus-origin scenes behave the same.

Example:

// drivers/scene/device.js
async onInit() {
  this.registerCapabilityListener('start_scene', async (sceneNumber) => {
    await this._writeSceneToKnx(sceneNumber);
    // fire same trigger used for inbound KNX scene events
    await this.homey.app.sceneStartedTrigger?.trigger(this, { scene_number: sceneNumber });
  });
}

// wherever inbound KNX telegrams are handled:
_handleInboundScene(sceneNumber) {
  this.homey.app.sceneStartedTrigger?.trigger(this, { scene_number: sceneNumber });
}

If KNX echoes local telegrams back, add a short debounce or flag to prevent double-triggering.

Effect:

Scenes started from Homey will now trigger the same Flow as when started from the KNX bus — consistent behavior, minimal change in logic.