Keyboard shortcuts

Press ← or → to navigate between chapters

Press S or / to search in the book

Press ? to show this help

Press Esc to hide this help

Soil sensors

Wire a moisture probe to a zone and the engine gets a measured gate: a saturated zone skips on its own, and a measured-dry zone can override a soft forecast-rain skip.

Supported paths in:

  • Ecowitt soil probes (WH51 and friends) via a LAN gateway poll: native, no cloud, with moisture and battery for every probe. Soil temperature and conductivity come only from the newer EC probes; a WH51 reports neither.
  • Any Home Assistant soil sensor entity, through an HA bridge source.
  • MQTT topics and HTTP webhooks for DIY probes.

Assignment is one step or two, depending on how the reading gets in.

  • An Ecowitt gateway channel or a Home Assistant entity is ready to assign as soon as the source reports. Open Settings > Zones, pick the zone, and choose the probe in its Soil moisture sensor dropdown. One picker lists both kinds, so there is no separate Home Assistant list. The probe’s card under Settings > Sensors or Settings > Devices binds the same zone, if you are already looking at it.
  • An MQTT subscription, an HTTP webhook, or any other source whose readings you map by hand needs the zone bound on the source first. In the source editor, set that subscription’s or mapping’s Bind to zone. That control is on MQTT soil subscriptions, on HTTP webhook and REST poller field mappings, and on YoLink and Tuya device mappings. Prometheus and InfluxDB take the same binding as a zone_slug on the query in the source’s JSON, and Davis WLL and the Home Assistant passthrough take a soil_zone_map on the source config. The value is then recorded as that zone’s own soil channel instead of as a global reading, which is the whole point of the field: an unbound MQTT soil subscription publishes as humidity and is merged into the general humidity reading, and a webhook or polled-API mapping has no soil option at all until a zone is bound. Save, then open the zone and pick that channel as its Soil moisture sensor. Both halves are required; binding the source alone does not gate the zone.

A zone-bound channel appears in the zone’s dropdown only after the source has published at least once, because that list is built from the readings LocalSky has recorded. One probe per zone is structural: a zone holds a single soil sensor. One zone per probe holds only when you bind from the probe’s card under Settings > Sensors or Settings > Devices, which releases the probe from whatever zone had it. The zone editor writes the zone you are editing and nothing else, so picking the same probe there leaves the earlier zone’s binding in place. The Sensors hub shows which zones each source feeds, and the step-by-step walkthrough is in Add your first soil sensor.

How the engine uses it:

  • Below the zone’s target band: the zone is eligible. Run length is unchanged; it comes from the weekly water balance.
  • Inside the band: healthy; scheduled runs still apply unless the saturation threshold says otherwise.
  • At or above saturation: the zone skips on its own, even when the day’s verdict is Run, and the skip reason gives the measured percent and the saturation threshold it crossed.
  • A probe that goes offline is flagged as an anomaly on the irrigation and zones views, but only for a zone bound to a source: channel (an Ecowitt gateway, MQTT, a webhook, an entry in the Home Assistant passthrough’s soil_zone_map) whose last reading above zero is more than 24 hours old. A zone bound to a Home Assistant entity through the HA bridge is never flagged offline, because there is no local history to tell a flatline from a blip.
  • A probe that reads as a wild outlier versus its neighbors is flagged the same way, once three or more zones are reporting a reading and the zone sits further from the yard median than the outlier threshold, 35 percentage points by default. On a two-probe yard nothing is judged an outlier.

The Sensors hub and each zone’s detail show the probe’s live reading, the target band, and a 7-day no-watering projection so you can sanity check that the moisture curve actually behaves like your yard.

A probe also unlocks the tuning report’s two calibration checks: the drying-drift check (does your soil dry at the rate the configured texture and root depth predict?) and the sprinkler-rate backout (what rate do your heads actually deliver, per the probe’s rise across waterings?). Both need LocalSky’s own recorded probe history, so they work for a zone bound to a source: channel (the Ecowitt gateway poll, MQTT, webhooks, the Home Assistant passthrough’s soil_zone_map); a zone bound to a Home Assistant entity through the HA bridge has no local history and reports that state honestly.