# Software Feature Specification

## SF-DQC: Data Quality & Calibration

**Software Feature ID:** SF-DQC  
**Mapped System Feature:** F-DQC (Data Quality & Calibration Features)  
**Version:** 1.0  
**Date:** 2025-02-01  

## 1. Feature Overview

The Data Quality & Calibration software feature implements comprehensive sensor validation, calibration management, and data quality assurance mechanisms. This feature provides the software implementation of automatic sensor detection, sensor type enforcement, sensor failure detection, and machine constants management.

### 1.1 Mapped System Features

- **F-DQC-01**: Automatic Sensor Detection
- **F-DQC-02**: Sensor Type Enforcement
- **F-DQC-03**: Sensor Failure Detection
- **F-DQC-04**: Machine Constants & Calibration Management
- **F-DQC-05**: Redundant Sensor Support

## 2. Static View - Component Architecture

```mermaid
graph TB
    subgraph "Application Layer"
        MCM[Machine Constants Manager]
        SV[Sensor Validator]
        CF[Calibration Framework]
    end
    
    subgraph "Detection & Validation"
        SD[Sensor Detector]
        STE[Sensor Type Enforcer]
        SFD[Sensor Failure Detector]
        RSM[Redundant Sensor Manager]
    end
    
    subgraph "Calibration Services"
        CS[Calibration Service]
        CC[Calibration Calculator]
        SF[Sensor Fusion]
    end
    
    subgraph "Storage Layer"
        DP[Data Pool]
        PM[Persistence Manager]
    end
    
    MCM --> SD
    MCM --> STE
    MCM --> CS
    SV --> SFD
    SV --> RSM
    CF --> CC
    CF --> SF
    SD --> DP
    STE --> DP
    SFD --> DP
    CS --> PM
    RSM --> SF
```

### 2.1 Component Interfaces

#### 2.1.1 Machine Constants Manager Interfaces

**Provided Interfaces:**
- `IMachineConstantsManager`: Main MC management interface
- `ICalibrationProvider`: Calibration data provider interface
- `IConfigurationManager`: Configuration management interface

**Required Interfaces:**
- `IPersistenceManager`: Persistent storage interface
- `ISensorDetector`: Sensor detection interface
- `IEventSystem`: Event notification interface

#### 2.1.2 Sensor Validator Interfaces

**Provided Interfaces:**
- `ISensorValidator`: Sensor validation interface
- `IDataQualityChecker`: Data quality verification interface
- `IFailureDetector`: Sensor failure detection interface

**Required Interfaces:**
- `ISensorDriver`: Sensor driver interface
- `IDiagnosticsManager`: Diagnostic reporting interface
- `ICalibrationService`: Calibration service interface

## 3. Dynamic View - Data Quality Sequences

### 3.1 Sensor Detection and Validation Sequence

```mermaid
sequenceDiagram
    participant SM as Sensor Manager
    participant SD as Sensor Detector
    participant STE as Sensor Type Enforcer
    participant MCM as Machine Constants Manager
    participant DIAG as Diagnostics Manager
    
    SM->>SD: detectSensors()
    SD->>SD: scanHardwareSlots()
    SD-->>SM: detected_sensors[]
    
    loop For each detected sensor
        SM->>STE: validateSensorType(slot, sensor_type)
        STE->>MCM: getExpectedSensorType(slot)
        MCM-->>STE: expected_type
        
        alt Sensor Type Match
            STE-->>SM: validation_success
        else Sensor Type Mismatch
            STE->>DIAG: reportDiagnostic(SENSOR_TYPE_MISMATCH)
            STE-->>SM: validation_failed
        end
    end
```

### 3.2 Sensor Failure Detection Sequence

```mermaid
sequenceDiagram
    participant SV as Sensor Validator
    participant SFD as Sensor Failure Detector
    participant SD as Sensor Driver
    participant DIAG as Diagnostics Manager
    participant SM as Sensor Manager
    
    SV->>SFD: monitorSensorHealth(sensor_id)
    SFD->>SD: getSensorStatus(sensor_id)
    SD-->>SFD: sensor_status
    
    SFD->>SFD: analyzeStatus(sensor_status)
    
    alt Sensor Healthy
        SFD-->>SV: health_ok
    else Sensor Failed
        SFD->>DIAG: reportSensorFailure(sensor_id, failure_type)
        SFD->>SM: markSensorFailed(sensor_id)
        SFD-->>SV: health_failed
    end
```

### 3.3 Machine Constants Update Sequence

```mermaid
sequenceDiagram
    participant MH as Main Hub
    participant CM as Communication Manager
    participant MCM as Machine Constants Manager
    participant STM as System State Manager
    participant PM as Persistence Manager
    
    MH->>CM: updateMachineConstants(new_mc_data)
    CM->>MCM: receiveMCUpdate(new_mc_data)
    MCM->>MCM: validateMCData(new_mc_data)
    
    alt MC Data Valid
        MCM->>STM: requestTeardown(MC_UPDATE)
        STM->>STM: executeTeardown()
        STM-->>MCM: teardown_complete
        MCM->>PM: persistMCData(new_mc_data)
        PM-->>MCM: persistence_complete
        MCM->>STM: requestReinitialization()
        STM->>STM: reinitializeSystem()
    else MC Data Invalid
        MCM->>CM: rejectMCUpdate(validation_error)
    end
```

## 4. Software Constraints

### 4.1 Performance Constraints
- **SWC-DQC-001**: Sensor detection must complete within 2 seconds during startup
- **SWC-DQC-002**: Sensor failure detection must not exceed 100ms per sensor
- **SWC-DQC-003**: Calibration calculations must complete within 10ms per sensor

### 4.2 Resource Constraints
- **SWC-DQC-004**: Machine Constants data limited to 16KB total size
- **SWC-DQC-005**: Calibration coefficients limited to 32 per sensor type
- **SWC-DQC-006**: Sensor failure history limited to 100 events per sensor

### 4.3 Reliability Constraints
- **SWC-DQC-007**: Sensor type validation must be enforced before any data acquisition
- **SWC-DQC-008**: Failed sensors must be immediately excluded from data reporting
- **SWC-DQC-009**: Machine Constants updates must be atomic and recoverable

### 4.4 Quality Constraints
- **SWC-DQC-010**: Redundant sensor fusion must provide 99.9% availability for critical parameters
- **SWC-DQC-011**: Calibration accuracy must be maintained within ±2% of reference values
- **SWC-DQC-012**: Sensor failure detection must achieve <1% false positive rate

## 5. Traceability Matrix - Software Requirements

| Software Requirement ID | Feature Mapping | Component | Verification Method |
|-------------------------|-----------------|-----------|-------------------|
| SWR-DQC-001 | F-DQC-01 | Sensor Detector | Hardware Test |
| SWR-DQC-002 | F-DQC-01 | Sensor Detector | Unit Test |
| SWR-DQC-003 | F-DQC-01 | Sensor Manager | Integration Test |
| SWR-DQC-004 | F-DQC-02 | Sensor Type Enforcer | Unit Test |
| SWR-DQC-005 | F-DQC-02 | Sensor Type Enforcer | Unit Test |
| SWR-DQC-006 | F-DQC-02 | Sensor Type Enforcer | Integration Test |
| SWR-DQC-007 | F-DQC-03 | Sensor Failure Detector | Unit Test |
| SWR-DQC-008 | F-DQC-03 | Sensor Failure Detector | Unit Test |
| SWR-DQC-009 | F-DQC-03 | Sensor Manager | Integration Test |
| SWR-DQC-010 | F-DQC-03 | Diagnostics Manager | Unit Test |
| SWR-DQC-011 | F-DQC-04 | Machine Constants Manager | Unit Test |
| SWR-DQC-012 | F-DQC-04 | Persistence Manager | Integration Test |
| SWR-DQC-013 | F-DQC-04 | Machine Constants Manager | Unit Test |
| SWR-DQC-014 | F-DQC-04 | Machine Constants Manager | Integration Test |
| SWR-DQC-015 | F-DQC-04 | System State Manager | Integration Test |
| SWR-DQC-016 | F-DQC-05 | Redundant Sensor Manager | Unit Test |
| SWR-DQC-017 | F-DQC-05 | Sensor Fusion | Unit Test |
| SWR-DQC-018 | F-DQC-05 | Redundant Sensor Manager | Integration Test |

## 6. Implementation Notes

### 6.1 Sensor Detection Architecture
- Hardware-based presence detection using dedicated GPIO pins
- I2C address scanning for digital sensors
- ADC threshold detection for analog sensors
- Dynamic sensor enumeration during startup and reconfiguration

### 6.2 Sensor Type Enforcement
- Fixed sensor-to-slot mapping defined in Machine Constants
- Hardware-based sensor identification where possible
- Software-based type verification using sensor response patterns
- Diagnostic reporting for configuration violations

### 6.3 Failure Detection Mechanisms
- Communication timeout detection (I2C, UART)
- Out-of-range value detection with configurable thresholds
- Signal stability analysis for analog sensors
- Response pattern analysis for digital sensors
- Trend analysis for gradual sensor degradation

### 6.4 Machine Constants Management
- JSON-based configuration format for human readability
- Schema validation for configuration integrity
- Versioning support for configuration evolution
- Atomic update mechanism with rollback capability
- Encryption support for sensitive calibration data

### 6.5 Redundant Sensor Support
- Dual sensor configuration for critical parameters (CO2, NH3)
- Sensor fusion algorithms: averaging, weighted average, voting
- Automatic failover to backup sensor on primary failure
- Cross-validation between redundant sensors
- Common-mode failure detection and reporting

### 6.6 Calibration Framework
- Multi-point calibration support (linear, polynomial)
- Temperature compensation for sensor drift
- Aging compensation based on usage time
- Factory calibration preservation
- Field calibration update capability

### 6.7 Error Handling
- Sensor detection failures logged as diagnostic events
- Type enforcement violations trigger immediate sensor disable
- Failure detection events propagated to diagnostics system
- Machine Constants validation errors prevent system startup
- Redundant sensor failures escalated based on criticality