SensorStat Card
The SensorStat card is the primary widget for displaying sensor data. Each card shows:
Current Reading
The large number in the center displays the latest sensor value in your preferred units. Unit conversion is automatic based on your account settings (e.g., Celsius to Fahrenheit).
Sparkline Trend
A small trend line below the reading shows recent values over time. This gives you a quick visual sense of whether the reading is stable, rising, or falling.
Sensor Label
The card title shows the sensor's display name. For multi-measurement sensors (like BME280), each measurement gets its own card with a disambiguated name.
Alarm Indicator
A colored border indicates alarm status:
- No border — Reading is within normal range
- Yellow border — Warning threshold crossed
- Red border — Critical threshold crossed
The alarm color is tied to the threshold configuration and updates in real time.
Inline Threshold Editor
Click any SensorStat card to open the inline threshold editor:
- Warning threshold — Set high and low warning levels
- Critical threshold — Set high and low critical levels
- Hysteresis — Dead-band value to prevent alarm flapping
Thresholds are saved per sensor and per device. When a threshold is breached, an alert event is created and optionally sent as an email or SMS notification.
Sensor Calibration
For sensors that support calibration (pH, EC, analog sensors), click the calibration icon on the card:
- Offset mode — Apply a simple zero-point correction
- Linear mode — Two-point calibration adjusting both slope and offset
- Live preview — See calibrated values update in real time as you adjust
Calibration parameters are stored in both Firestore (persistence) and RTDB (Pi-side application).
Unit Conversion
Sensor readings are automatically converted to your preferred units:
- Temperature — Celsius, Fahrenheit, or Kelvin
- Pressure — hPa, inHg, or psi
- Volume — Liters or gallons
- Flow rate — Liters per minute or gallons per minute
Change your unit preferences in Account Settings > Units. The conversion applies across all dashboard surfaces including analytics charts and alarm thresholds.
No Data State
If a sensor card shows "No data":
- Check that the sensor is wired correctly
- Verify the flow is deployed and running on the Pi
- Check the device health panel for connectivity issues
- See Sensor Not Reporting
Next Steps
- Controlling Actuators
- Alarm Thresholds for detailed alert configuration