# **ASF Sensor Hub** ## **Feature Engineering Specification** ## **Sensor Data Acquisition Features** ## **1\. Feature Overview** ### **Feature Name** Sensor Data Acquisition Features ### **Feature ID** FEAT-DAQ ### **Subsystem** ASF Sensor Hub (Sub-Hub) ### **Target Platform** ESP32-S3–based embedded system ### **Scope** This feature defines the capabilities of the Sensor Hub related to: * Environmental sensor data acquisition * Local preprocessing and filtering * Timestamping and preparation of sensor data for persistence and communication This feature **does NOT include**: * Main Hub processing * Cloud analytics * Control logic * OTA, diagnostics, or persistence mechanisms (referenced only as dependencies) ## **2\. Purpose and Engineering Rationale** Modern poultry farm automation systems require **high-resolution, reliable, and time-correlated environmental data** to enable: * Accurate environmental control * Early fault detection * Advanced analytics and machine learning The Sensor Data Acquisition feature ensures: * Deterministic sensor sampling * Noise-resilient measurements * Temporal traceability of data * Decoupling of acquisition from communication and control This aligns with **distributed intelligence principles** used in leading international poultry automation systems. ## **3\. Feature Decomposition** The Sensor Data Acquisition feature is decomposed into the following sub-features:

Sub-Feature ID	Name
F-DAQ-01	Multi-Sensor Data Acquisition
F-DAQ-02	High-Frequency Sampling and Local Filtering
F-DAQ-03	Timestamped Sensor Data Generation

## **4\. Functional Description** ### **4.1 F-DAQ-01: Multi-Sensor Data Acquisition** #### **Description** The Sensor Hub acquires environmental data from multiple heterogeneous sensors connected to dedicated hardware interfaces. #### **Supported Sensor Types** * Temperature * Relative Humidity * Carbon Dioxide (CO₂) * Ammonia (NH₃) * Volatile Organic Compounds (VOC) * Particulate Matter (PM) * Light Intensity Each sensor: * Is mapped to a predefined hardware slot * Has a dedicated driver abstraction * Can be independently enabled or disabled #### **Key Characteristics** * Concurrent sensor handling * Modular sensor driver architecture * Runtime awareness of sensor presence ### **4.2 F-DAQ-02: High-Frequency Sampling and Local Filtering** #### **Description** For each enabled sensor, the system performs multiple raw readings per acquisition cycle and applies a local filtering mechanism to produce a single representative value. #### **Sampling Behavior** * Each sensor is sampled **N times per cycle** (default: 10) * Sampling occurs within a bounded time window * Sampling frequency is configurable via Machine Constants #### **Filtering Behavior** * Filtering is executed locally on the Sensor Hub * Filtering algorithms are abstracted and replaceable * Examples (non-exhaustive): * Moving average * Median filter * Outlier rejection #### **Objective** * Reduce sensor noise * Improve data stability * Avoid propagating raw sensor jitter upstream ### **4.3 F-DAQ-03: Timestamped Sensor Data Generation** #### **Description** Each processed sensor value is associated with a timestamp generated by the Sensor Hub. #### **Timestamp Characteristics** * Generated after filtering completion * Represents the effective measurement time * Based on system time (RTC or synchronized clock) #### **Sensor Data Record** Each record includes: * Sensor ID * Sensor type * Filtered value * Unit of measurement * Timestamp * Data validity status ## **5\. Operational Flow** ### **Normal Acquisition Cycle** 1. Detect enabled sensors 2. Initialize sensor drivers (if not already active) 3. Perform high-frequency sampling per sensor 4. Apply local filtering 5. Generate timestamp 6. Create sensor data record 7. Forward data to: * Data Persistence component * Communication component (on request) ## **6\. Constraints and Assumptions** ### **Constraints** * Sensor acquisition must not block system-critical tasks * Sampling and filtering must complete within a bounded cycle time * Memory usage must be deterministic ### **Assumptions** * Sensor presence detection is handled by a separate feature * Time synchronization is provided by another system component * Storage and communication are decoupled from acquisition ## **7\. Architecture Diagram (PlantUML)** ### **7.1 Sensor Hub Component Diagram** ```mermaid graph TD subgraph "Sensor Hub" SD["Sensor Drivers"] --> SE["Sampling Engine"] SE --> FE["Filtering Engine"] FE --> TS["Timestamp Service"] TS --> DB["Sensor Data Buffer"] end SD -->|"raw samples"| SE SE -->|"sampled data"| FE FE -->|"filtered value"| TS TS -->|"timestamped record"| DB ``` ### **7.2 Acquisition Cycle Sequence Diagram** ```mermaid sequenceDiagram participant S as Sensor Driver participant SE as Sampling Engine participant FE as Filtering Engine participant TS as Timestamp Service S ->> SE: read() loop N samples SE ->> S: sample() end SE ->> FE: raw sample set FE ->> TS: filtered value TS ->> FE: timestamp ``` ## **8\. Formal System SHALL Requirements** ### **8.1 Requirement Style** * Each requirement uses **“The system shall …”** * Each requirement has a unique ID * Requirements are atomic and testable ### **8.2 Requirements List** #### **Multi-Sensor Acquisition** * **REQ-DAQ-001** The system shall support acquisition of data from multiple environmental sensor types simultaneously. * **REQ-DAQ-002** The system shall provide a dedicated software driver abstraction for each supported sensor type. * **REQ-DAQ-003** The system shall acquire sensor data only from sensors detected as present and enabled. #### **High-Frequency Sampling & Filtering** * **REQ-DAQ-004** The system shall sample each enabled sensor multiple times within a single acquisition cycle. * **REQ-DAQ-005** The system shall apply a local filtering mechanism to raw sensor samples to produce a single representative value. * **REQ-DAQ-006** The system shall allow configuration of sampling count and filtering parameters via system configuration data. #### **Timestamped Data Generation** * **REQ-DAQ-007** The system shall associate each processed sensor value with a timestamp. * **REQ-DAQ-008** The system shall generate timestamps after completion of filtering. * **REQ-DAQ-009** The system shall include sensor identifier, sensor type, value, unit, timestamp, and validity status in each sensor data record. ## **9\. Feature-to-Requirement Traceability**

Feature ID	Requirement IDs
F-DAQ-01	REQ-DAQ-001, REQ-DAQ-002, REQ-DAQ-003
F-DAQ-02	REQ-DAQ-004, REQ-DAQ-005, REQ-DAQ-006
F-DAQ-03	REQ-DAQ-007, REQ-DAQ-008, REQ-DAQ-009