Microcontrollers are small, low-power, and versatile devices that can run embedded software for various applications. However, they also have limited resources and security features, which can affect their performance and safety. If you want to optimize your microcontroller code for speed and security, here are some tips you can follow.
The compiler is the tool that translates your source code into executable binary code for the microcontroller. Different compilers may have different levels of optimization, support, and compatibility for your target device and platform. You should choose a compiler that offers the best balance between code size, speed, and quality. Some factors to consider are the compiler's optimization options, debugging features, libraries, and documentation.
From my point of view here is some tips to accelerate execution: 1- Reduce code size as much as possible ( by using a low level programming language, optimizing algorithms & enabling compiling optimization flags) 2- Keep the Data transfers for MCU devices as DMA as much as possible. 3- Use the possible fast memories available in your target (memories coupled directly to the CPU). 4- If you are using a CPU independent transfer data device like DMA, it is better to not use the same memory bus to fetch instructions and transfer Data (example : instructions use the ram1, data should use the ram2, & CPU doesn't use the same bus to handle ram1 & ram2). 5- Better execute from RAM when having external flash .
Compiler optimization enhances code performance by making compiled output more efficient. It operates at low, mid, and high levels. Low-level optimizations involve basic operations like instruction reordering. Mid-level optimizations focus on loops and functions, using techniques such as inlining and loop unrolling. High-level optimizations involve complex transformations like algorithm changes. Common optimizations include constant folding, dead code elimination, and loop optimization. Compiler flags like -O2 enable optimizations, and -Os optimizes for size. Profile-Guided Optimization (PGO) tailors optimizations based on profiling data. Vectorization converts scalar operations into vector operations for efficiency.
Timers are counters that generate interrupts at specified intervals, such as every millisecond, second, or minute. Interrupts and timers can help you improve your microcontroller's speed and security by reducing latency, saving power, and performing time-critical tasks.
Reduce resource use and optimize algorithms. When possible, use hardware acceleration. For data security, use authentication and encryption. Update firmware and apply security patches. For robustness, use testing and code reviews.
It is an old technique, that divides the code into similar and non-similar jobs. then quantify a similar task make a call function and always use that call function where it is needed, this will reduce the main memory space and also speed up the controller processing.
The data types and structures you use in your code can affect how much memory and processing power your microcontroller consumes. You should use the smallest and simplest data types and structures that can store and manipulate your data without losing accuracy or functionality. For example, you can use unsigned integers instead of signed integers if you don't need negative values, or use bit fields instead of booleans if you need to store multiple flags in one byte. You should also avoid using floating-point numbers, strings, or dynamic memory allocation if possible, as they can be slow and memory-intensive.
Use physical locks, seals, shields or enclosures to prevent unauthorized access or tampering Provide ongoing protection for your digital asset and intellectual property against continuous emerging threat
We can use an AI and a machine learning for both subjects. But on the other hand decreas data size and increasing security for data is different target. and we couldn't achieve good results in this situation.
Efficient use of data types and structures in microcontroller programming is crucial for optimizing memory and performance. Utilize fixed-size data types like `uint8_t` for consistent memory usage. Minimize padding and reduce wastage by aligning data structures based on the microcontroller's rules. Employ bitfields and bitwise operations for compact storage of flags and small integers. Avoid dynamic memory allocation (`malloc`, `free`) due to fragmentation and overhead. Optimize enums for readability and use them instead of constants. Choose appropriate data structures like arrays or linked lists based on application requirements. Eliminate redundant data storage and compute derived values on demand.
Defining the proper typeof variable has essensial role in the speed of code execution. When a single byte is enough to store a value, do not use integer type.
The algorithms and logic you implement in your code can also impact your microcontroller's speed and security. You should design your algorithms and logic to be as simple, clear, and modular as possible, avoiding unnecessary loops, branches, or calculations. You should also use appropriate control structures, such as switch-case instead of if-else, or break and continue instead of goto, to improve readability and efficiency. Moreover, you should test and debug your code regularly, using tools such as simulators, emulators, or logic analyzers, to identify and eliminate any errors or vulnerabilities.
Optimizing algorithms and logic in microcontroller programming is vital for efficient resource usage. Choose appropriate algorithms and data structures, considering time complexity and memory usage. Reduce loop iterations and unroll loops selectively to minimize overhead. Minimize function calls, inline small functions, and optimize conditional branches. Utilize cache-friendly patterns to reduce memory latency. Consider parallelism cautiously, dividing tasks for multithreading if applicable. Optimize interrupt service routines (ISRs) for brevity. Utilize profiling tools to identify bottlenecks, focusing optimizations on time-consuming code sections. Regularly benchmark the optimized code to measure improvements accurately.
Understand the requirements of different applications, if you don’t need to sample as fast because the input waveform cannot change so fast, then reduce the sampling frequency
When using integer values, using certain operators (such as shift left) instead of arithmetic operations (such as multiplication by two) can speed up the code. Even more complex operations can be simplified to a sequence of bit operations. This is very helpful, especially in real-time filter implementation.
Optimize your logarithms and logic.
Interrupts and timers are features that allow your microcontroller to respond to external or internal events without polling or waiting. Interrupts are signals that trigger a subroutine to execute when a certain condition is met, such as a button press, a sensor reading, or a communication request. Timers are counters that generate interrupts at specified intervals, such as every millisecond, second, or minute. Interrupts and timers can help you improve your microcontroller's speed and security by reducing latency, saving power, and performing time-critical tasks. However, you should also use them wisely, avoiding nested, long, or frequent interrupts, or conflicting or inaccurate timers, as they can cause instability, inconsistency, or corruption.
Security measures are essential to protect your microcontroller code from unauthorized access, modification, or exploitation, such as encryption, authentication, and integrity. Encryption is the process of transforming your code or data into a secret format that can only be decoded by authorized parties. Authentication is the process of verifying the identity and legitimacy of your code or data sources and destinations. Integrity is the property of ensuring that your code or data is not altered or corrupted during transmission or storage. To achieve these security measures, you can use algorithms such as AES, RSA, or ECC; methods such as passwords, certificates, or tokens; and techniques such as checksums, hashes, or signatures.
You need to scale the design of math routine to your data path for optimal use of time and memory. Using an Arduino to process vision data when an ARM may be a better choice for math processing should be considered to reduce power consumption and heat.
One of the best ways to speed up and secure your microcontroller code is to learn from others who have done it before. You can find and study examples, tutorials, or best practices from online sources, such as blogs, forums, or repositories, or offline sources, such as books, magazines, or courses. You can also ask for feedback, advice, or help from other developers, experts, or communities, who can share their insights, experiences, or solutions. By learning from others, you can improve your skills, knowledge, and confidence, and avoid common mistakes or pitfalls.
To speed up and secure microcontroller code: Optimize code for efficiency. Reduce power consumption. Minimize code size. Use an RTOS for task management. Employ interrupts efficiently. Configure peripherals carefully. Implement security measures. Conduct code reviews and testing. Plan for firmware updates. Secure communication and authentication. Enforce access control. Implement error handling. Secure data storage. Keep libraries updated. Maintain documentation. Implement monitoring and logging. Ensure compliance with standards.