Embedded systems have become an integral part of electronics recently. Used in anything from automotive items to medical devices, it requires very specific knowledge and expertise in designing and developing them. However, even the most experienced designers can get it wrong with embedded systems.
Embedded design is a specialty field that requires knowledge of hardware and software development, including embedded software development. It involves designing and developing electrical devices integrated into other systems. However, designers usually make common mistakes that can lead to overspending, project delays, and even unsuccessful products.
It is best to steer clear of the following common embedded design mistakes:
1. Excessively Intricate Design
By adding unnecessary features or components that could make the system difficult to maintain and debug, system designers may overcomplicate the system.
A straightforward design approach is frequently more effective and easier to maintain over time.
2. Ineffectively Controlled Power Usage
Power consumption is a critical aspect of embedded design. Poor power management can lead to unstable systems or a reduced life of the battery.
Designers should pay great attention to the power consumption of the system and use techniques like sleep modes in order to reduce energy consumption during periods when the system is idle.
3. Poor Choice of Components
Component selection for an embedded system may have the highest impact on performance and stability. Designers must carefully check every component that would be depended on for performance and compatibility while making sure the right one fits the intended purpose.
4. Hardware and Software Incompatibilities
Mismatched components for hardware and software may cause a system to become unstable as well as suffer from poor performance. The designer ensures that hardware and software agree, and the drivers and firmware required are installed correctly.
5. Inadequate Safety Protocols
Security is a big issue for embedded systems, especially when those systems are employed in demanding environments or handle sensitive data.
Designers should include enough security elements, including encryption and authentication procedures, to ensure the system is safe.
Typical Problems Faced by Embedded Software Engineers
Labor expenses may be lowered for weeks or months if these mistakes are avoided or corrected, especially as the delivery date draws near. It will make it possible to reuse the software for similar projects in the future, which will enhance the application's robustness and quality.
One Big Superloop
We are unable to alter the distinct execution speeds of various code segments when real-time software is developed as a single, big loop. Not every real-time system must operate at the same pace. Selectively slowing down the less crucial portions of the code is one method to reduce utilization if the CPU is being overworked. However, this approach only works if the code was written with a real-time executive as a model or if the multitasking features of an RTOS are utilized.
Large if-then-else and Case Statements
In embedded programming, large if-then-else or case statements are common. These are problematic from three angles:
- Debugging such lines is difficult since code ultimately takes so many different paths. If statements are nested, it becomes far more challenging.
- There is a noticeable disparity between the worst-case and best-case execution times. Selecting the longest approach could lead to time problems or CPU underutilization.
- As the number of branches rises, testing structured code and attaining decision coverage become much more difficult. Consequently, it is best to limit the number of branches.
Similar results are often obtained using computational methods. Using lookup tables, Boolean algebra, or constructing a finite state machine as a jump table are some methods to reduce a 100-line if-else expression to less than 10 lines of code.
Related: The Challenges of Cross-Platform Development in Embedded Software
Details About Configuration Found in #define Statements
Embedded programmers commonly utilize #define statements to declare array restrictions, register addresses, and configurable constants in their code. Even though it's common, this strategy is bad because it makes it harder to reuse the software for similar applications.
The problem arises from the #define that is expanded throughout the source code. The value might therefore show up in the code in twenty different places. Finding the exact location in the object code where the value needs to be altered is challenging. As an example of software reusability, have a look at this situation: Each register #defined at each location implements the code of an I/O device. That code cannot be used again if a second identical device is installed on the system. Instead, the code must be copied, with only the port addresses changed. Using a data structure that translates the I/O devices' registers is an other method.
Another issue is that #defining statements are frequently used with type definitions instead of actual constants. #define statements should only be used in macros and where the scope requires that a #define be used instead of a constant.
Error detection and handling are afterthoughts that are accomplished by trial and error
Error handling and detection are rarely significantly incorporated into software systems. Instead, the main goal of software design is regular operation, and exception and error handling are added after the fact by the programmer. In order to address problems that arise during testing and debugging, the programmer either adds error detection everywhere—often when it is not required but still impacts timing and performance—or adds no error handling code at all.
Either way, the error handling is badly designed and difficult to maintain. Instead, like any other requirement, error detection should be incorporated into the system's architecture from the start. Therefore, in an application that is intended to be a finite state machine, an exception can be thought of as an input that starts a process and changes the state.
By including a lightweight or binary-encoded error recording system with timestamping and maybe offline processing into the infrastructure, such issue management and detection with minimal overhead during development can be accomplished. After that, this system can be pre-processed or optimized for production builds.
Conclusion
In conclusion, the design of embedded systems is a complicated area where basic mistakes can result in expensive delays and problems. If you want to succeed, simplify designs, ensure that hardware and software function together, choose intelligent components, manage power efficiently, prioritize security, stay up to speed with technology changes, maintain good documentation, and employ efficient coding techniques. Additionally, make error management an essential part of the design process. This allows you to create embedded systems that are future-ready, dependable, and efficient.
