ASF_01_sys_sw_arch/System Design/Features/[DAQ] Sensor Data Acquisition Features.md

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

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

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