Environment Control & Actuators¶

Kamerplanter closes the control loop between sensors and actuators: the system measures temperature, humidity, CO₂ and the vapor pressure deficit (VPD), evaluates these values against configured rules, and uses them to control devices like fans, humidifiers or irrigation valves. You can intervene directly at any time by manually switching an actuator on or off.

Prerequisites¶

• At least one location with an area (Site & Location) is set up — see Locations & Substrates
• For automatic control via Home Assistant: HA integration is set up — see Home Assistant Integration
• For sensor rules: sensors are delivering measurements — see Sensors

The Sensor-Actuator Control Loop¶

Every automatic control action follows the same cycle:

flowchart LR
    S[Sensor measures<br/>Temperature / rH / CO₂ / VPD] --> E{Rule engine<br/>evaluates}
    E -->|Threshold exceeded| P{Priority<br/>check}
    E -->|All within range| W[Wait<br/>until next measurement]
    P -->|No conflict| A[Actuator command<br/>is sent]
    P -->|Conflict detected| K[Conflict<br/>resolution]
    K --> A
    A --> H[Hysteresis timer<br/>starts]
    H --> S

The backend evaluates rules and schedules cyclically every 30 seconds. Every executed command is permanently stored with timestamp, trigger (schedule, rule, manual, safety, fallback) and success status — there is no dedicated view for it in the UI yet, see For Technical Users / Self-Hosters.

Adding Actuators¶

An actuator is a controllable device (e.g. a fan, light, or pump) assigned to an area (Location).

Add a New Actuator¶

1. Open Environment Control > Actuators & Control in the sidebar.
2. Click Add actuator.
3. Choose Site and Location, and give it a name.
4. Choose actuator type and protocol — depending on the protocol, one more required field appears (see below).
5. Optional: power draw (used for the consumption overview) and notes.

Protocol Comparison¶

Safe Value Envelope¶

Actuator Types¶

Operating Actuators¶

Every actuator's card shows its current state (on/off/fault) and whether the device is reachable online.

• Turn on / Turn off send a direct command to the actuator immediately — regardless of what any active rule or schedule currently intends.
• If the transmission fails (e.g. because Home Assistant is unreachable), the system doesn't report it as an error — it automatically creates a manual task instead: "Device is not directly reachable — the command was queued as a manual task instead."

Automatic Control: Priority and Hysteresis¶

For every actuator, Kamerplanter cyclically evaluates which control source should currently win. When multiple sources compete for the same actuator, the following order applies:

flowchart TB
    M[1. Manual Override<br/>highest priority, time-limited]
    S[2. Safety rules<br/>e.g. overtemperature exhaust]
    R[3. Rule-based control<br/>sensor thresholds]
    Z[4. Schedule<br/>lowest priority]
    M --> S --> R --> Z

When a rule or schedule wins, the resulting command is sent to the actuator and — just like a direct command — clamped to the configured safe value envelope.

Configuring Hysteresis¶

Sensor rules use hysteresis to prevent an actuator from switching on and off every second around a threshold that's just barely reached:

Example: VPD humidifier control

  Switch ON at:  VPD > 1.5 kPa   ← upper threshold (on_threshold)
  Switch OFF at: VPD < 1.2 kPa   ← lower threshold (off_threshold)
  Min runtime:   5 minutes        (min_on_duration_seconds)
  Min pause:     3 minutes        (min_off_duration_seconds)

You set these hysteresis values per rule via the API, see For Technical Users / Self-Hosters — there is no form for it in the UI yet.

When Home Assistant Is Unreachable¶

If a command to Home Assistant fails — whether triggered by a click on the card, a rule, or a schedule — Kamerplanter marks the actuator as offline and automatically creates a manual task, instead of discarding the command without result. If the actuator itself is configured with the Manual protocol, the same applies to every action from the start — a live command is never sent.

Emergency Stop¶

For emergencies there is an immediate emergency stop.

Besides this fire-alarm scenario, the system knows two more predefined scenarios that are currently only triggerable via the API:

Every affected actuator is addressed individually: if switching off a single device fails (e.g. because Home Assistant can't currently reach it), the emergency stop is not aborted — every other device is still switched off. Kamerplanter then tells you exactly which devices weren't reached, for example: "Emergency stop partially executed: 4 actuator(s) switched off, 1 actuator(s) could NOT be switched off (Exhaust Fan Tent 1). Please check and disconnect these devices manually right away." — so you know immediately which device to disconnect by hand.

For Technical Users / Self-Hosters¶

The following functions are already fully implemented in the backend, but still lack a user interface — you can currently only reach them via the REST API, under the tenant-scoped path /api/v1/t/{tenant_slug}/. Read calls accept any active membership; write calls (create, command, override, rules, schedules, emergency stop) require at least the Grower role; deleting an actuator requires Admin.

Frequently Asked Questions¶

See Also¶

• Setting Up Sensors
• Growth Phases
• Home Assistant Integration
• VPD Optimization
• Tank Management