Creation of MQTT timer which can be call by Node red "call service" node

Third party integrations Node-RED
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1

Context
I am building an irrigation controller (ESP32) which uses MQTT to communicate with Home assistant. The entities on the device include a series of switches and associated timer (in this case 12 of each) for turning zones on and off.

Solution overview
I am using the MQTT switch for the switches as this allows the use of the Node-red call service “switch” domain and all the functionality that comes with it.

Problem
I am unable to find an equivalent for the timer although the Node-red “call service” node does have a “Timer” domain. The key difference is that I need to pass the “duration” to the MQTT entity. The node has a property of duration which can be used to set the duration, but I’m not sure how the integration works with HA, and hence, how I should configure the MQTT entity to pick it up. Effectively the timer is a switch with a property of duration. The MQTT switch does not have properties/functions (like the MQTT light).

Options I’ve considered
One option is to use the MQTT domain in the node-red “call service” node and communicate directly with the device. But I’m sure there is a simple solution to pass a property to the MQTT switch.

I had a quick look at the Timer helper, but I’m not sure I can use it to send messages to the ESP32(via mqtt).

Any suggestions would be much appreciated.

Thanking you in advance.

2

You will need to publish the value to the topic of the entity you want to update. You can use either a call service or an mqtt out node.

3

Thanks for your response. Apologies for the tardiness in replying.

I’m not sure I’ve fully understood your suggestion. Is there a way to publish to topic in the Node red “call service” node? If I did that, would it update an attribute in MQTT switch?

For the time being, I’ve decided to simply use the MQTT node.

Many thanks for your time.

4

Yes, the mqtt node and publish from a call service is basically the same thing.

image

{
   "topic":"/homeassistant/hello",
   "payload":"This is great"
}
5

Apologies, I meant using the “call service” node with Domain as switch (rather than mqtt) - as I have defined the entity as a mqtt switch. Let me try this out.

Many thanks.