This node provides a light transition service within Home Assistant for lights that don't have a built-in transition capability. It does this by sending multiple light.turn_on messages in a loop through the second output, calculating the appropiate brightness as it goes.

Once the transition is complete or is cancelled, the original message will be sent through the first output.

When adding this node to your flow you must also add a call service node to the second output, with the specific configuration detailed below.

Input Message to start a transition

The node expects an input msg which contains the following to start a light transition:

• msg.topic specifies the target light or light group - this is the only mandated property
• msg.brightness_start and msg.brightness_end integers, between 0 and 255 - if not provided, 0 and 255 are assumed
• msg.transition_time tells the node how long to take to make the transition between the defined brightnesses, in seconds - if not provided, it defaults to 60

Note: if msg.brightness_end is 0 the target light(s) will have light.turn_off sent to them at the end of the transition

Other control messages

There are also two other control messages which the node will accept:

• a msg.payload of cancel will immediately stop the transition wherever it is
• a msg.payload of finish will immediately set the target light(s) to the msg.brightness_end value, effectively jumping to the end of the transition

Home Assistant note

The original release of this node contained the Home Assistant call service node within it. This meant that it didn't work for anyone other than me as Node Red doesn't appear to support importing your own Home Assistant configuration node when adding a subflow-derived module to your flows.

That is the reason why this node requires you to attach a call service node to the second output with this specific configuration:

• domain: {{call_service_domain}}
• service: {{call_service_service}}
• entityId: {{call_service_entity}}
• data: call_service_data
• dataType: jsonata

Or you can import this flow JSON:

[{"id":"032e33ef3d45e13d","type":"api-call-service","z":"c04e9d3d.431e8","name":"Set light state","server":"58215890.7c8288","version":5,"debugenabled":false,"domain":"{{call_service_domain}}","service":"{{call_service_service}}","areaId":[],"deviceId":[],"entityId":["{{call_service_entity}}"],"data":"call_service_data","dataType":"jsonata","mergeContext":"","mustacheAltTags":false,"outputProperties":[],"queue":"none","x":1490,"y":600,"wires":[[]]}]