node-red-contrib-sensor-consensus 0.1.1
A Node-RED sensor-fusion / consensus node: fuses latest readings from multiple sensors into a single trusted aggregate with staleness windows, quorum, disagreement detection, and a latched threshold trigger. Purpose-built 4-output event model (Trigger / R
node-red-contrib-sensor-consensus
A Node-RED sensor-fusion / consensus node. Readings from multiple
sensors (keyed by msg.topic) are fused into a single trusted
aggregate, and a trigger latches when that aggregate crosses a
configured threshold — with freshness (staleness windows),
quorum, and disagreement detection as first-class features
rather than afterthoughts.
Averaging three healthy humidity sensors is easy. What existing aggregation nodes don't answer is what happens when one of them goes quiet, sticks, or drifts: a dead sensor's last reading silently skews the average forever, and nothing tells you a trigger didn't fire because trust was lost rather than because the value was fine. This node makes every one of those decisions observable.
Highlights
- Two type modes (per node instance): Numeric — mean, median, min, max, or trimmed mean over the latest value from each source — or Boolean — vote rules (Any / Majority / All / At least N) over the fraction of sources reporting true, with configurable true/false value lists.
- Trust built in: per-source staleness windows, fresh-source quorum, minority reports when a sensor disagrees with its peers, and a configurable Hold/Release policy for quorum loss while triggered.
- Latched threshold trigger with direction (above/below) and hysteresis, plus runtime commands to move thresholds, adjust the staleness window, disable/enable decisions, and remove or reset sources.
- Four purpose-built outputs — Trigger, Release, Query, Events —
where outputs 1 and 2 carry only what genuinely happened, and every
blocked, rejected, or suppressed action is observable on the Events
output with
msg.ignored = true. - Heartbeat snapshots for watchdogs, and optional persistence across deploys/restarts with wall-clock staleness re-evaluation on restore.
Install
From the Node-RED palette manager, or:
cd ~/.node-red
npm install node-red-contrib-sensor-consensus
Documentation
The embedded node help (in the editor sidebar) is a complete
reference. Detailed documentation, examples, and troubleshooting live
in the project wiki.
The authoritative record of design decisions is
sensor-consensus-design.md in this
repository.
Sibling nodes
This node shares its event envelope (msg.ignored, msg.source),
command conventions, and output-exclusivity guarantees with
node-red-contrib-timer-events
and
node-red-contrib-timer-threshold
— downstream flows can process events from all three with the same
code.
Testing
npm test
runs the standalone assertion harness (no framework dependencies;
144 checks across 8 suites at the time of writing). Publishing is
gated on the same harness via prepublishOnly.
License
Apache-2.0. Includes Douglas Crockford's public-domain cycle.js for
persistence serialization.
