Dynamic Thermostat

A Node RED module, a dynamic thermostat means you can enter a desired temperature as msg.payload a hysteresis as msg.payload and the current temperature as msg.payload for heating on or off, so its very dynamic and you don't have to specify any settings in the node itself

Installation

This node requires node 10.x+.

$ cd ~/.node-red
$ npm install node-red-contrib-dynamic-thermostat

Configurations

The node has 1 input with (4 topic-payloads) and 1 output (object with 4 payloads) As described below. In the output you have onoff it contains a boolean if the heater have to go on or off. If the hysteresis is active onoff is null:

Input

You have to set 4 payloads for success function:

• topic: switch, payload: true/false/auto, you can force to switch the thermostat on or off, "auto" to return to automatic mode
• topic: target, payload: target temperatur, e.g. 23
• topic: current, payload: current temperatur, e.g. 19 (comes from your thermometer)
• topic: hysteresis, payload: target temperatur, e.g. 0.3

Output

The output is a object in the payload as following:

{
  switch: true | false,
  onoff: true | false | null,
  current: 19,
  target: 23,
  hysteresis: 0.3
}

Example Flow

[{"id":"7c89a60c.c53b78","type":"tab","label":"Flow 1","disabled":false,"info":""},{"id":"3bca5a6f.b51676","type":"inject","z":"7c89a60c.c53b78","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"target","payload":"20","payloadType":"str","x":230,"y":180,"wires":[["7382ac40.df0f54"]]},{"id":"6717a2da.fcd2ec","type":"debug","z":"7c89a60c.c53b78","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":670,"y":220,"wires":[]},{"id":"485cee9b.051ff","type":"inject","z":"7c89a60c.c53b78","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"current","payload":"21","payloadType":"str","x":220,"y":240,"wires":[["7382ac40.df0f54"]]},{"id":"9ffdf3df.750a7","type":"inject","z":"7c89a60c.c53b78","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"hysteresis","payload":"0.3","payloadType":"str","x":230,"y":300,"wires":[["7382ac40.df0f54"]]},{"id":"7382ac40.df0f54","type":"dynamic thermostat","z":"7c89a60c.c53b78","name":"","x":460,"y":220,"wires":[["6717a2da.fcd2ec"]]}]