# Calibration

The capacitive probe does not provide a universal moisture percentage. Calibrate
this individual sensor in the soil and pot where it will be used.

## Soil sensor

Record the raw A0 value after it has stabilized in each condition:

| Condition | Raw ADC value | Notes |
|---|---:|---|
| In air | | Probe clean and dry |
| Dry soil | | At the chosen "needs water" condition |
| Normally watered soil | | Desired everyday condition |
| Saturated soil (optional) | | Let excess water drain first |

Keep insertion depth, orientation and location consistent. Do not bury exposed
electronics above the sensing section. A future 0–100% entity should map the
measured dry/wet endpoints and clamp values outside that range. It will be a
relative practical scale, not laboratory volumetric water content.

## Pump flow

Before any automatic watering:

1. Put the inlet in the normal reservoir and route the outlet into a measuring
   container.
2. Prime the tube.
3. Run several supervised pulses with a known total duration, such as 10 s.
4. Measure delivered milliliters and calculate `ml / seconds`.
5. Repeat to estimate variability at the actual lift height and tube length.

| Trial | Runtime (s) | Volume (ml) | Flow (ml/s) |
|---|---:|---:|---:|
| 1 | | | |
| 2 | | | |
| 3 | | | |

Automatic watering must later use short pulses, settling delays, sensor fault
checks, per-cycle limits and a daily runtime or volume limit. None of that logic
is enabled in the initial firmware.