Probably many hardware engineers should have the same experience as me, when we first worked, the drawing of circuit diagrams was mainly imitation. Connect according to the Demo board, imitate the old product drawing, and modify it on the mature circuit diagram. In a word, "imitation". When you draw a PCB, it really feels like it's looking at each other and bumping into each other. If you can get the line through and complete the function, you feel that you have done it. At that time, after the circuit was returned to the board, various difficulties were always encountered. All kinds of board modifications, all kinds of instability, all kinds of debugging, all kinds of flying wires. When designing circuits, some signal quality, electromagnetic compatibility, long-term reliability, robustness, derating design, etc. are not considered at all.
I always envy others for making more complex circuits, and I don't know where the challenges of complex circuits are, and I don't know what key points to pay attention to when designing circuits. I always design circuits based on my own preferences and feelings, and the results are naturally not satisfactory. At that time, the Internet was not yet developed, there was still very little information to be found on the Internet, and there was no learning path like "100,000 Whys of Hardware". One of the hilarious things at the time: I went to ask an older engineer why someone else had serpentine traces on their boards? He has never been engaged in the design of radio frequency or high-speed digital circuits, and he replied to me very confusedly: "I don't know, it is probably to prevent the signal from radiating out and interfering with other signals." Because they are all high-speed signals, the higher the rate, the easier it is to radiate. So, I made a joke: I took the highest rate signal (the clock) on an FPGA board and ran it in a serpentine way. This is a typical joke that does not understand the principle and blindly imitates. Fortunately, when I was still young, I left my first job with all kinds of confusion and went to "Huawei", with my hardware dream: to make more advanced hardware, more complex hardware, more reliable hardware, and more valuable hardware.
After joining Huawei, I felt that Huawei's biggest advantage was that it had a lot of historical accumulation, and formed "specifications", "guides", and "checklists". Especially when I first joined the company, the whole company was in the "standard" movement, writing specifications for everything, everyone writing specifications, and looking at specifications for positions, performance, and technical levels. (Large companies use KPIs to guide, which is easy to make a "movement"). Everyone followed the "specification" indiscriminately, but there were actually many problems: at that time, when the schematic diagram was reviewed, the most common thing I heard was "the specification is written like this", and there were some problems with this:
1. The person who writes the specification is not necessarily of a high level, or the writing is not meticulous, and if there is a mistake, it will be even more harmful.
2. The specification sometimes inhibits the developer's thinking, and everything is in accordance with the specification, which may not be suitable for the actual design scenario; For example, if I need a low-cost design, but the specification emphasizes high quality, it may not be applicable.
3. After the specification is obtained, it will also lead to some developers not thinking, for example, the crystal oscillator requires that the pF capacitor be placed above 50MHz for power supply filtering, and the capacitor below 50MHz is not used. Everyone doesn't want why, and naturally they don't know why; What is the basis for this content? The test results, simulation results, and cases are not described in detail; Another example is network port transformer protection, indoor and outdoor, according to the design requirements of various EMC standards can be directly drawn up, but few people think why, do not know what the test results are, and are helpless when they encounter difficulties. Indeed, the norms formed by such simple rules sometimes improve work efficiency and product quality, but the tools are also developed, and people are degraded, which is inevitable.
4. The selection of some devices is not suitable for writing specifications, because the development of devices is too fast, and it is possible that the devices will be eliminated when you write the specifications. For example, after the X86 processor entered the field of communication, the processor selection specification became redundant.
Specifications do have a benefit, and engineers who follow them strictly will rarely make low-level mistakes, improving the quality of the development base. The disadvantage of specifications is that engineers sometimes don't think about the principle and always look for specifications. However, not all work is suitable for specification. Hardware engineers should be able to jump out of the "reference circuit" and "specification", and think about the problem and design from the principle.
It is precisely because I mainly did technical pre-research projects in my first job, although the complexity of the circuit is not so high, but what I do is often some industry gaps, and I need to find technical breakpoints, so I have cultivated a lot of independent thinking work habits. When you see a bunch of specifications, you often want to understand the basis for formulating the specifications, the writing ideas, and the physical principles. Sometimes when you see some norms, you will think about the reasons behind them, and you will also find that some of the norms themselves are wrong and out of place. Over time, as the knowledge system becomes more and more complete, I understand the microstructure and physical principles of electronic components. In the knowledge architecture of hardware, a way of thinking that uses physical principles to explain engineering specifications has gradually formed.
Engineers, especially young engineers, should avoid blind imitation and superstitious design specifications. Through continuous learning, improve cognition, and achieve "the ability to use physical principles to understand engineering phenomena and understand the use of design specifications". Hardware engineers are not simply connected, but need to be able to finally combine principles and engineering to do development clearly. The resulting hardware is of high quality and has few problems, allowing for quick analysis and resolution of problems even if they occur.
Penetrate the physical model of the essence of hardware and understand the hardware system in a comprehensive manner.
The key to hardware proficiency is understanding the system, not just mastering the tools.
In addition to the control of the circuit itself, it is also necessary to control the entire hardware project, and the hardware engineer is also an engineering businessman.
"Software is the key, hardware is the connection." This sentence is a self-deprecation of engineers for their own simplicity, and it is also a satire that many engineers only see the surface of the hardware and software design, but do not understand the system deeply. Indeed, for hardware engineers, it seems oversimplified and superficial to think that hardware works just to draw the schematic well. Indeed, the expression of hardware schematic diagram is usually expressed in the form of interconnection of chip interfaces, and it seems that as long as these chips are connected according to the diagram, the hardware design is completed. But the truth is far from that simple.
The complexity of hardware design goes far beyond the wiring on the drawings, and it involves in-depth knowledge of hardware system design, circuit detail design, component selection, electromagnetic compatibility, thermal management, processor internals, and many other fields. Every detail can affect the performance, reliability, and cost of the final product. Hardware engineers need to be not only proficient in theory, but also have rich practical experience and be able to solve various problems encountered in practical operations.
Designing a successful hardware product requires consideration of architecture design, operational reliability, power management, signal integrity, thermal management, mechanical structure, and many other factors. All of this requires designers to have comprehensive knowledge and experience, and to be able to consider all aspects from a systematic perspective. Simple wiring is just the surface, the real challenge is how to optimize each link to make the whole system work at its best.
The design and implementation of hardware involves not only the splicing of circuit boards, chips and cables, but also the profound principles of engineering, physics and materials science. To truly understand the role and significance of hardware, we must go beyond the surface and delve into the inner workings of hardware and how they combine with software, user needs, and innovative technologies to create a myriad of possibilities.
We'll explore the inner workings of the hardware world and uncover the complexities behind those seemingly simple devices. Let's enter the wonderful world of hardware together, uncover its mysteries, and feel its infinite potential.
There are many things that need to be done in hardware design beyond drawing the schematic and the PCB diagram itself.
If "hardware is not connected", where is the threshold of hardware?
Simple hardware and complex hardware: First of all, I have always believed that hardware design needs to distinguish between "simple hardware" and "complex hardware", some simple hardware, for example, like: MP3, e-cards, Bluetooth headsets. The circuit structure is relatively simple, the development threshold is relatively low, and it does not require a very experienced engineer to develop, and the problem may not be big, even if there is a problem, the cost of checking the problem and correcting the problem will not be particularly high, so the requirements for engineers are not particularly high. However, if the power consumption of the circuit is higher than 20W and the number of pins exceeds 10k, the design and debugging of the circuit will make the solution of the problem complicated, and once the problem occurs, it is often not so easy to analyze and deal with. Therefore, when your product belongs to the design of complex hardware, you should still find some professional and experienced engineers, at least people with problem solving ideas, to engage in related work to control complex systems.
Simple hardware is more suitable for enterprises and individuals with advantages in the supply chain to develop and break through.
Towards RF: Since the rate of ADC is limited after all, and it is impossible for all systems to be made into software defined radios, RF circuits still need experience accumulation and hardware design. However, due to the power of simulation tools, RF engineers' proficiency in the use of software has become more important, rather than experience as in the early days, and it requires deep theoretical knowledge and understanding. RF requires a certain threshold because it requires a deep theoretical knowledge of electromagnetic fields. If you're working in RF, congratulations, your fortress hasn't been breached yet. But as the trend progresses, RF work will become easier and easier.
Entering the chip: When I was at Huawei, some bigwigs came from hardware backgrounds, had a deep theoretical foundation of network protocols, product application experience, and had a deep application foundation for processors, or FPGA design skills. Since hardware personnel have more accumulation of chip applications and are easy to think about chip design from the perspective of chip application, it is a good choice to have the opportunity to go inside the chip.
In the future, with the fading of the Chinese population dividend and the disappearance of labor cost advantages, the current SMT and PCB processing is likely to disappear from China, and there is no related low value-added product production like Europe and the United States, but it is necessary to go to areas similar to India, Vietnam and other regions with labor cost advantages to process and produce.
Combine software and hardware to become a comprehensive talent:
The structural efficiency of multiple knowledge is greater than that of single knowledge. The structure of human knowledge is the same as that of an enterprise, and efficiency is greater than operational efficiency.
The same is true for knowledge, we just say from the perspective of software, the cost of software solution is low, ignoring the cost of hardware in this case; Vice versa. The combination of software and hardware can find the lowest point of global cost from a technical point of view. In the project, the software can simulate some interfaces with the IO port, such as SPI master, I2C master, I2C slave, UART slave, and UART master. Sometimes, under the premise that the microcontroller does not have these interfaces and cannot change the solution in time, the software can reduce the hardware development cost; For some analog signal filtering, it becomes a digital signal through the ADC. It can be filtered with both analog and digital filters. The two can be combined, the hardware does not need more devices, and the software does not need to be more computational. Otherwise, the chips with higher computing power will not bring a little change. Both hard and soft engineers are hurt.
Become an engineer in the combination of software and hardware in the embedded aspect, even including structural design, ID design, website design, and RF; To become a comprehensive talent, you are more likely to become a geek, you only need an idea, you can put it into practice and change the world. At the same time, full-stack engineers can also go to engineering and do system integration.
Promoted to system designer: In Huawei's technology development roadmap, a hardware engineer has three paths: 1. Manager; 2. Hardware experts; 3. System engineer. Looking at the development path of engineers in Huawei's various product lines, it is easier for a hardware engineer to grow into a system engineer, and it is easier for a software engineer to grow into a project manager.
This is due to the fact that the knowledge system of hardware engineers is relatively more complete, and it is easier to understand the work in other fields.
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