Dynamic adding speed of fan in Node Red node

Third party integrations Node-RED
1

Hi, struggling with the correct format to add a dynamic value for fan speed.

This is the output I want to use to set the speed:
payload.data.fan_level

This is what I tried in the call service node data field:
image

{"percentage":"{{payload.data.fan_level}}"}
{"percentage":"payload.data.fan_level"}
{"percentage":{{payload.data.fan_level}}}
{"percentage":payload.data.fan_level}
both as expression and json… please help me with the correct format :slight_smile:

Edit: some other tries not successful:
{"percentage":"$number(payload.data.fan_level)"}
{"percentage":$number(payload.data.fan_level)}

2

Thus to be clear, this works:

image
image559×881 11.7 KB

Now I want the value of payload.data.fan_level to be in the place of 32

3

I know I may not swaer tag :grimacing:… but @Kermit can you help me out?

4

What about

{"percentage":msg.payload.data.fan_level}

?

5

Tried it also no luck

6

From the call-service node documentation

If the incoming message has a payload.data that is an object or parsable into an object these properties will be merged with any config values set.

Merge Resolution

As seen above the data property has a lot going on in the way of data merging, in the end, all of these are optional and the rightmost will win if a property exists in multiple objects
Config Data, Global Data, Flow Data, Payload Data ( payload data property always wins if provided

If you are constructing an object (as you are) for the Data Field in a call-service node, you should always use JSONata (J: expression) as mustache templating does not work correctly.

JSONata expressions evaluate on the incoming message, and you don’t need the msg. bit at the front.

Hence

{ "percentage": payload}

will evaluate payload and create the object with that value.

You can use nested objects using the dot notation, so payload.data.fan_level would also work quite nicely.

However, I believe that the call service node will attempt to merge the incoming payload.data object. I am not about to test this, but my guess is that you are probably ending up with data field being set to {“percentage”: 32, “fan_level”: 32}. A bit like ‘The Fly’.

My suggestion would be to avoid using payload.data in the first place. Perhaps payload.setting.fan_level?