Embedded Software: Simple vs. Complex

Embedded software is integral to modern technology, ranging from simple home appliances to advanced autonomous systems. It can be broadly classified into two categories: simple (Non-OS) and complex (OS-driven) embedded software.

Simple Embedded Software: When simplicity and low cost are priorities and an OS would be overkill

Examples:

1. Power or temperature monitoring systems.
2. Simple applications in household appliances like ovens and washing machines.

Characteristics:

1. Typically designed for applications with few tasks.
2. No operating system necessary.
3. Software interacts directly with the microcontroller’s hardware (registers etc.), forcing rewrites if the hardware changes.

Advantages:

1. Low power consumption, low cost.
2. Can be developed by electronics engineers, no need for computer engineers because basic embedded programming knowledge is sufficient.
3. Deterministic: By sidestepping the complexity of OS schedulers, simple systems achieve predictable performance.
4. Fewer abstraction layers make verification and validation straightforward, which is a huge advantage for safety-critical certification.

Complex Embedded Software: When multi-tasking, file operations and networking necessitate an OS

Examples:

1. IoT devices requiring seamless connectivity.
2. Systems involving advanced sensor integration or navigation.

Characteristics:

1. Runs on an operating system that manages tasks and system resources.
2. Capable of handling multiple tasks and applications simultaneously.
3. Safety-critical certification is difficult. To make it easier, safety-critical parts should be developed as separate, simpler modules.

Advantages:

1. Less competition and higher profit margins, provided that you have a strong technical team.
2. Requires computer engineers to lead the development because of increased software complexity. Besides embedded software courses, related concepts of algorithms, data structures, and operating systems are also a core parts of computer engineering but not electronics engineering.
3. The OS abstracts low-level hardware management, enabling developers to focus on application logic. A POSIX-compliant application, for instance, can run on any POSIX-supporting OS with minimal changes.
4. Easier for new developers to adapt and contribute due to less hardware dependency.
5. A broad range of pre-existing libraries simplifies development.
6. Operating systems provide abstraction layers (e.g., Linux Device Model), allowing drivers to expose standard interfaces while interacting with specific hardware.
7. Simplifies adding new functionality (e.g. telemetry) or adapting to new hardware (e.g. new/different sensors).
8. With minor modifications, software can be tested on a PC, speeding up testing with less effort (no need for electronic cards, power supplies, etc.) and reducing bugs.

Operating systems can also be categorized as either simple (e.g., FreeRTOS) or complex (e.g., real time Linux with ROS) - but let's leave that topic for another blog post.

Music: Peyk - Don Kafa