A Node-RED node that provides a simple PID controller.
Run the following command in your Node-RED user directory - typically ~/.node-red
npm i node-red-node-pidcontrol
PID controller node.
This node ONLY expects a numeric msg.payload containing the current reading.
It will output the correction that needs to be applied in order to move to the preset set point value.
The damping factors are typically in the range 0 - 1. See Wikipedia for more details on PID controllers.
The set point may be overridden by msg.setpoint. If you do so the edit box value can be used as the initial value.