node-red-contrib-change-detect

A Node-RED node that forwards messages only when the value has changed. Supports numbers, booleans, strings, and objects.

Installation

npm install node-red-contrib-change-detect

Inputs

• payload any: Value to check.
• reset (optional) boolean: Clear last value; next message is always forwarded.

Outputs

• payload any: Original value, forwarded only when changed.
• changeDetect object: { previous, current, changed, type, tolerance }

Configuration

• Tolerance: Minimum numeric difference to trigger output (0 = any change).
• Initial Value: Optional: pre-set the last value on deploy.

Tips

• First message is always forwarded (no previous value to compare).
• Objects and arrays are compared via deep JSON comparison.
• Tolerance only applies to numeric values.

License

MIT (c) sr.rpo