The Sensors Layer defines all devices and measurement systems used by AOFS controllers to monitor irrigation, energy usage, water distribution, and environmental conditions. All AOFS-compliant deployments must implement the sensors and documentation systems specified here.

AOFS uses four main sensor categories:

1. Soil Monitoring Sensors
2. Water Monitoring Sensors
3. Power / Energy Sensors
4. Optical / Camera Monitoring Systems

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Purpose: Measure soil conditions to optimize irrigation schedules.

Required Measurements:

• Soil moisture (volumetric water content) per zone
• Soil temperature (optional but recommended)
• Electrical conductivity (optional; for salinity monitoring)

Placement Guidelines:

• At least one sensor per irrigation zone; multiple sensors for large or heterogeneous fields
• Sensors should be placed at root depth appropriate to the crop type

Data Collection:

• Sample at a frequency suitable for crop needs (typically 15–60 min)
• Data logged locally in Field Controller and synced with Farm/HQ controllers

Calibration & Maintenance:

• Sensors must be calibrated according to manufacturer recommendations
• Regular inspection to prevent soil compaction or damage

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Purpose: Ensure safe and efficient water delivery.

Required Measurements:

• Tank levels: FULL and LOW float switches
• Flow meters on main and zoned pipelines
• Pressure sensors for distribution lines
• Optional: rain gauges (tipping bucket) for weather lockouts

Placement Guidelines:

• Tank sensors at critical fill/drain points
• Flow meters before distribution manifolds
• Pressure sensors after pumps and at main lines

Safety Requirements:

• Water sensors must enforce Field Controller fail-safes (pump cutoff, overflow prevention)
• Must function independently of network connection

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Purpose: Monitor energy consumption and optimize PUE (productive use of electricity).

Required Measurements:

• DC battery voltage and current
• Pump energy consumption
• Valve power usage
• Optional: solar panel output monitoring

Placement Guidelines:

• Measure energy at the main DC bus and key loads
• Optional per-zone energy monitoring for detailed efficiency analysis

Integration:

• Data feeds into Field Controller for fail-safe shutdowns on low voltage
• Logged for auditing and analytics

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Purpose: Supplement sensor data with visual field observations.

Use Cases:

• Crop growth monitoring
• Pest or disease detection (optional, non-critical for irrigation)
• Soil surface moisture and coverage assessment

Requirements:

• Cameras must be oriented for optimal coverage of zones
• Images or video must be timestamped and logged
• Data should integrate with Field Controller for automated or semi-automated analysis

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* All sensor readings must be logged locally on the Field Controller. * Logs include timestamp, sensor ID, measured value, and status/quality flags. * Data must be synced with Farm Controller for aggregation and with HQ Controller for analytics. * Field workers may document crop growth, harvest outcomes, and environmental observations via Field Survey Interfaces, complementing automated measurements.

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* All sensors must be regularly calibrated according to manufacturer specifications. * Field inspections are required to prevent sensor drift, damage, or misplacement. * AOFS-compliant deployments must maintain logs of calibration and maintenance events.

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* All AOFS deployments must implement at minimum:

1. Soil moisture per irrigation zone
2. Tank LOW/FULL switches
3. Flow meters and pressure sensors on all irrigation manifolds
4. Power monitoring for pumps and valves

* Optional sensors (temperature, conductivity, cameras) are recommended for advanced optimization, but not mandatory.

* All data must be timestamped, logged locally, and synchronized according to federation rules.

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* Field Controller Layer * Farm Controller Layer (Local / Federated) * Hydraulic & Water Systems * Electrical & Control Interfaces * Optical Monitoring (Cameras)