IoT Hardware and Software Explained – CWISA Module 8 Summary

IoT systems are built on a combination of hardware components and software layers that work together to sense, process, and act on data.

In CWISA Module 8, we explore how IoT devices are designed — from physical components like sensors and microcontrollers to software layers like firmware and operating systems.

This knowledge is essential for designing scalable and efficient IoT solutions.

Off-the-Shelf vs Custom IoT Devices

Organizations typically choose between two approaches when deploying IoT devices.

Off-the-Shelf Devices

These are ready-made solutions from vendors such as Monnit or Dragino.

Advantages

• Quick deployment
• Vendor support
• Pre-tested hardware

Limitations

• Limited customization
• May not fit unique use cases

Custom Devices

Custom-built devices are designed using individual components.

Advantages

• Fully customizable
• Optimized for specific environments
• Supports unique features (e.g., energy harvesting)

Challenges

• Requires engineering expertise
• Longer development time

Hardware Levels of IoT Devices

Custom IoT devices can be built at three levels:

Chip Level

• Individual microcontrollers
• Lowest level of design

Controller Board Level

• Adds PCB + interfaces
• More practical for development

Computer Board Level

Examples:

• Raspberry Pi
• Single Board Computers (SBCs)

👉 These provide higher processing power and flexibility.

Microcontrollers and Interfaces

Microcontrollers are the core of IoT devices, integrating:

• CPU
• Memory
• Storage

GPIO (General Purpose Input/Output)

GPIO pins allow devices to interact with external components.

Communication Protocols

UART

• Simple serial communication

SPI

• High-speed communication
• Used for sensors and displays

I2C

• Multi-device communication
• Widely used in IoT sensors

Sensors and Actuators

IoT devices act as cyber-physical systems.

Sensors

Sensors collect data from the environment.

Examples:

• Temperature
• Humidity
• Pressure
• Motion

Analog-to-Digital Conversion (ADC)

Sensors convert physical signals into digital data.

Actuators

Actuators perform physical actions.

Examples:

• Motors
• Relays
• Valves

IoT Software Stack

IoT devices rely on multiple layers of software.

Firmware

• Low-level software
• Controls hardware
• Manages boot process

Operating System

Often lightweight Linux-based systems.

Responsibilities:

• Resource management
• Running applications
• Supporting services

Applications and Services

• Applications → user-facing
• Services → background processes

Location Services in IoT

IoT devices often need to determine their location.

Triangulation

• Uses angles from reference points

Trilateration

• Uses distance measurements
• Based on geometric calculations

Practical Example – Raspberry Pi Sensor

A common IoT project:

• Raspberry Pi 4
• DS18B20 temperature sensor
• Python script to read data

Why This Matters

Custom implementations enable:

👉 Automation
👉 Scalability
👉 Efficiency

This concept is known as engineering amplification — using automation to multiply operational output.

Summary

IoT solutions rely on the seamless integration of hardware and software components. Understanding how sensors, microcontrollers, and software layers interact enables engineers to design efficient, scalable, and intelligent systems.

📌 I recently passed the CWISA certification and I’m documenting my full learning journey.

👉 Follow this series to master IoT system design.