Embedded AI Data Logger for Predictive Maintenance

This project implements a real-time predictive maintenance system on STM32 microcontrollers using Zephyr RTOS and TensorFlow Lite for Microcontrollers. The system collects sensor data, performs on-device anomaly detection, and enables early equipment failure prediction to minimize unplanned downtime.

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🔧 Key Features

🏭 Factory Method Pattern for modular creation of machines and sensors
⏱ Real-time data logging on STM32 with Zephyr RTOS
🔍 On-device anomaly detection using TensorFlow Lite for Microcontrollers
⚡ Early failure prediction to reduce unplanned downtime

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🧱 Modular & Scalar Machine Creation with Factory Design Pattern

⚙️ Machine-Sensor Configuration
Each industrial machine is equipped with specific sensors for predictive maintenance:

1️⃣ AIR_COMPRESSOR
    📊 Temperature: 60-100°C • 📏 Pressure: 72-145 psi • 📳 Vibration: 0.5-2.0 mm/s
    Monitors overheating, pressure fluctuations, and mechanical wear

2️⃣ STEAM_BOILER
    📊 Temperature: 150-250°C • 📏 Pressure: 87-360 psi
    Tracks thermal efficiency and safety thresholds

3️⃣ ELECTRIC_MOTOR
    📊 Temperature: 60-105°C
    Winding insulation safety range

🧩 Factory Structure

                        ┌────────────────────┐
                        │   SensorFactory    │ ← Abstract Creator
                        └────────────────────┘
                                  ▲
                                  │
                ┌─────────────────┴─────────────────┐
                │                                   │
       ┌─────────────────┐                ┌──────────────────┐
       │  createSensor() │                │ Machine Creation │
       └─────────────────┘                └──────────────────┘
      Creates sensor objects              Uses factory to build
    (Temp, Pressure, Vibration)            complete machines

💡Usage Example

// Create a machine by providing the name and TYPE
MachineHandle handle = create_machine("Compressor1", AIR_COMPRESSOR);

// Set and read sensor values
set_sensor_value(handle, "Temperature", 42.5f);
float temp = get_sensor_value(handle, "Temperature");

// Clean up
destroy_machine(handle);

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🏗 System Architecture

[📡 Sensors] → [💻 STM32 (Zephyr RTOS)] → [🧠 TensorFlow Lite] → [⚠️ Anomaly Detection] → [📊 Logging/DFU]

🛠️ Tools and Software

   ⎔ VS Code - Primary IDE for STM32 firmware development
       • Extensions: Cortex-Debug, Zephyr IDE, CMake Tools
   ⎔ Zephyr RTOS - Real-time operating system for resource-constrained devices
   ⎔ Tensflow Lite for MCUs - On-device ML inference (quantized models)
   ⎔ CMake - Build system for Zephyr projects
   ⎔ dfu-utils - Firmware updates via USB DFU protocol

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📂 Project Code Structure

📁 Data-Logger-Predictive-Maintenance/   
│── 📁 src/                                   (Core application source)
│   ├── 📄 main.c                             (Zephyr application entry point)
│   ├── 📄 sensor.cpp / .h                    (Sensor base class + implementations)
│   ├── 📄 sensor_wrapper.cpp / .h            (C-compatible sensor interface)
│   ├── 📄 tflite_wrapper.cpp / .h            (TensorFlow Lite inference interface)
│   ├── 📄 autoencoder_model.cc / .h          (Embedded ML model definition)
│── 📁 CMakeLists.txt/                        (Build system configuration)
│── 📁 prj.conf/                              (Zephyr kernel config)
│── 📁 sample.yaml/                           
│── 📁 tflite-micro/
│   ├── 📄 tensorflow/                        
│   │   ├── 📄 lite                           (TensorFlow Lite for Microcontrollers) 
│── 📁 data/
│   ├── 📄 simulated_data.py                 (Sensor data simulator)
│   ├── 📄 simulated_data.zip                (Compressed simulated sensor data)
│   ├── 📄 autoencoder.tflite                (Quantized TF Lite model)                
│   ├── 📄 simulated_data                    
│   │   ├── 📄 machine_1                     (Machine type 1: Air Compressor)
│   │   │   ├── 📄 machine_1_temp.csv        (Temp sensor values)
│   │   │   ├── 📄 machine_1_pressure.csv    (Pressure sensor values)
│   │   │   ├── 📄 machine_1_vibration.csv   (Vibration sensor values)
│   │   ├── 📄 machine_2                     (Machine type 2: Steam Boiler)
│   │   │   ├── 📄 machine_2_temp.csv        (Temp sensor values)
│   │   │   ├── 📄 machine_2_pressure.csv    (Pressure sensor values)
│   │   ├── 📄 machine_3                     (Machine type 3: Electric Motor)
│   │   │   ├── 📄 machine_3_temp.csv        (Temp sensor values)
│── 📄 README.md                             (Documentation)