1493  The Things - Connected Devices

1493.1 Overview

In the Internet of Things, “things” are the physical devices that bridge the digital and physical worlds. These connected devices range from tiny sensors embedded in infrastructure to complex smart appliances in our homes. Understanding how to design, select, and deploy these devices is fundamental to building successful IoT systems.

This topic is covered across four focused chapters:

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flowchart TD
    THINGS[Connected Devices] --> FUND[Fundamentals<br/>Categories & Design Trade-offs]
    THINGS --> FORM[Form Factors<br/>Enclosures & Materials]
    THINGS --> POWER[Power Management<br/>Battery Life & Optimization]
    THINGS --> LIFE[Lifecycle<br/>Testing, OTA & Provisioning]

    FUND --> FUND_TOPICS[Device categories<br/>Design triangle<br/>Characteristics]
    FORM --> FORM_TOPICS[Size constraints<br/>IP ratings<br/>Materials]
    POWER --> POWER_TOPICS[Power budget<br/>Sleep modes<br/>Battery selection]
    LIFE --> LIFE_TOPICS[Environmental testing<br/>OTA updates<br/>Provisioning]

    style THINGS fill:#2C3E50,stroke:#16A085,color:#fff
    style FUND fill:#16A085,stroke:#2C3E50,color:#fff
    style FORM fill:#E67E22,stroke:#2C3E50,color:#fff
    style POWER fill:#16A085,stroke:#2C3E50,color:#fff
    style LIFE fill:#E67E22,stroke:#2C3E50,color:#fff

Figure 1493.1: Connected Devices topic structure: Four focused chapters covering fundamentals, form factors, power management, and lifecycle

{fig-alt=“Topic overview showing four connected devices chapters: Fundamentals (device categories, design triangle, characteristics), Form Factors (size constraints, IP ratings, materials), Power Management (power budget, sleep modes, battery selection), and Lifecycle (environmental testing, OTA updates, provisioning)”}

1493.2 Chapter Guide

1493.2.1 1. Fundamentals and Categories

What you’ll learn: - The four main IoT device categories: wearables, consumer, industrial, and infrastructure - The device design triangle: balancing features, cost, and power - Key device characteristics and selection criteria - Real-world trade-off examples (Apple Watch vs Fitbit vs pedometer)

Best for: Starting your connected devices journey, understanding device types and design principles.

1493.2.2 2. Form Factors and Enclosures

What you’ll learn: - Size constraints from components, batteries, antennas, and heat dissipation - Enclosure material selection (ABS, polycarbonate, aluminum, silicone) - IP ratings and environmental protection requirements - Mounting methods and user interaction design - LED status indicator best practices

Best for: Physical design decisions, environmental protection, user interface elements.

1493.2.3 3. Power Management

What you’ll learn: - Power budget analysis and battery life calculations - Sleep mode implementation (active, sleep, deep sleep) - Radio protocol power comparison (Wi-Fi vs BLE vs LoRa vs cellular) - Battery chemistry selection for different environments - Cold weather considerations for lithium batteries

Best for: Battery-powered device design, maximizing operational lifetime.

1493.2.4 4. Lifecycle Management

What you’ll learn: - Environmental testing requirements (temperature, humidity, mechanical, EMC) - Over-the-air (OTA) update architecture with dual-bank safety - Device provisioning workflows (SoftAP, BLE, SmartConfig) - Biocompatibility requirements for skin-contact devices - Inclusive design for diverse user populations

Best for: Production readiness, long-term device management, regulatory compliance.

1493.3 Learning Path

TipRecommended Reading Order
  1. Start with Fundamentals to understand device categories and the design triangle
  2. Then read Form Factors to learn physical design considerations
  3. Continue to Power Management for battery life optimization
  4. Finish with Lifecycle for production and maintenance

Each chapter builds on concepts from previous chapters, but can also be read independently if you need specific information.

1493.4 Key Concepts Preview

Concept Chapter Quick Definition
Design Triangle Fundamentals Balance features, cost, and power - optimize for two
IP Rating Form Factors Ingress protection against dust and water
Deep Sleep Power Ultra-low power mode (~10-100µA) with RTC wake
Dual Banking Lifecycle Safe OTA with automatic rollback on failure
Provisioning Lifecycle Connecting device to network and user account

1493.5 What’s Next

After completing these chapters, continue to Connecting Together to learn how IoT devices discover, pair, and communicate with each other to form functional ecosystems.