Skip to content

README.md

Latest commit

 

History

History
89 lines (62 loc) · 4.6 KB

README.md

File metadata and controls

89 lines (62 loc) · 4.6 KB
Raw

MQTT State Messages

Cerasmarter publishes heating, hot-water, auxiliary-sensor, and general status documents. The payload envelope and retention depend on whether Home Assistant discovery is enabled.

Topic modes

When HomeAssistant.Enabled is false, the objects below are published directly and non-retained on the configured legacy topics:

  • MQTT.Topics.HeatingValues
  • MQTT.Topics.WaterValues
  • MQTT.Topics.AuxiliaryValues
  • MQTT.Topics.Status

When HomeAssistant.Enabled is true, each object is wrapped in its category and published retained:

Category Topic Payload envelope
Heating cerasmarter/<DeviceId>/Heating/state {"Heating": {...}}
Hot water cerasmarter/<DeviceId>/Water/state {"Water": {...}}
Auxiliary sensors cerasmarter/<DeviceId>/Auxiliary/state {"Auxiliary": {...}}
General/diagnostics cerasmarter/<DeviceId>/General/state {"General": {...}}

The example files show the unwrapped legacy form. Boolean state properties are serialized as the strings "true" and "false" for compatibility with existing dashboards and Home Assistant templates.

Heating values

ExampleHeatingValues.json contains decoded heating values and a mirror of the current command state.

Important fields:

  • FeedMaximum: maximum feed temperature reported by the boiler.
  • FeedCurrent: current boiler feed temperature.
  • FeedSetpoint: effective setpoint. It is null until a CAN setpoint has been observed when Cerasmarter is not controlling the bus.
  • RequestedFeedSetpoint: last requested direct setpoint, which can differ from the effective calculated setpoint.
  • Outside: boiler or configured auxiliary outside temperature.
  • Pump, Season, Working: decoded heating operating states.
  • Enabled, FeedBaseSetpoint, FeedCutOff, FeedMinimum, Adaption, DynamicAdaption, OverrideSetpoint: current stable command state.
  • AuxiliaryTemperature, AmbientTemperature, TargetAmbientTemperature: external and room-reference inputs.
  • ValveScaling, ValveScalingMaxOpening, ValveScalingOpening: valve-based control state.
  • Boost, BoostTimeLeft, OnDemandBoostDuration, FastHeatup: boost and fast-heat-up state.

An effective 10 °C setpoint represents the manufacturer's heating-off request. Internally calculated values below it are clamped to exactly 10 °C.

Hot-water values

ExampleWaterValues.json contains:

  • Maximum: maximum temperature allowed by the boiler dial.
  • Current: current hot-water temperature.
  • Setpoint: current setpoint; null until observed when Cerasmarter is not controlling the bus.
  • CFSetpoint: continuous-flow setpoint; null until observed.
  • Now: instant-demand state.
  • Buffer: storage-buffer operating state.

Auxiliary sensors

ExampleAuxValues.json contains one property per configured sensor label. Each sensor has a numeric Temperature and string-valued Reachable state:

{
  "Return": {
    "Temperature": 30.1,
    "Reachable": "true"
  }
}

Labels and DS18B20 addresses are configured as described in Auxiliary Sensors.

General status and diagnostics

ExampleStatus.json contains the burner and controller diagnostics:

  • GasBurner: decoded flame state.
  • Error: decimal representation of the boiler error byte; 0 normally means no reported error.
  • FreeHeap, HeapSize: current and total heap bytes.
  • FilesystemUsed, FilesystemSize: LittleFS usage in bytes.
  • FlashSize: detected flash capacity in bytes.
  • ChipModel, ChipRevision, CpuCores, CpuFrequency: ESP32 runtime information.

Pump, season, heating-operation, boost, and fast-heat-up states belong to the heating payload, not the general payload.

Availability and cadence

With Home Assistant enabled, availability is retained at cerasmarter/<DeviceId>/availability. MQTT Last Will publishes offline; a successful connection publishes online. Availability is tied to the MQTT connection and is independent of how frequently a CAN value changes.

Some CAN-backed values are published on their normal polling cadence while others only change when the boiler reports a new frame. Consumers should use availability for connection health and timestamps/history for measurement freshness. A combined status request can ask Cerasmarter to republish its current state; see Request Parameters & Status.

See the API reference for command topics, discovery behavior, and security notes.