If you want to learn hardware, what should you learn?

Want to learn hardware , What should I learn ？

Hardware engineers are usually divided into four categories ： Entry Hardware Engineer  | Complete simple tasks under the guidance of others 、 Ordinary hardware engineer  | Able to complete basic tasks 、 Senior Hardware Engineer  | Lead the project and complete difficult projects and expert hardware engineers  | Leading projects and making breakthroughs in related industries .

If you want to be an expert Hardware Engineer , We should pursue such a realm ： We should have broad academic theories 、 Rich experience in project practice , We should also have a positive spirit of reflection and innovation , This article can be seen as a guide to help Xiaobai step by step to become an expert Hardware Engineer , I will learn through my own experience , Make a technical summary for you in brief language , This is the summary of my learning experience , It can also stand the test of practice , It is suggested that pure Xiaobai finish reading .

01 welding

About welding , In fact, it is the necessary hands-on ability of entry-level hardware , Through years of welding , Also summed up some experience , And used the multi clock technique , The welding effect is greatly improved .

· Control the temperature during welding , Generally in 300 ~ 380℃ Between , Too high temperature will easily burn the chip ;

· The pins must be aligned before soldering the chip , Because after the chip is fixed , It is difficult to move the position of the chip ;

· Do not use round head soldering iron for desoldering , Because this kind of soldering iron head is inconvenient to support welding , Usually use a knife head or horseshoe head ;

· Welding due to the use of rosin , It will leave a layer of black silk on the board , Wash it with water or alcohol ;

· After using the electric iron , Tin the tip of the soldering iron , It can prevent oxidation , Play a protective role .

02 Instruments and Apparatuses

● A multimeter

A multimeter , Why is it called a multimeter ？ Because a multimeter is almost universal , It is a multifunctional 、 Multi range measuring instrument , DC current can be measured 、 DC voltage 、 AC voltage 、 Resistance and audio level , Some can also measure AC current 、 Capacitance 、 Inductance and some parameters of semiconductor , But we usually only use it to measure resistance and voltage .

Use the multimeter correctly , It can not only measure quickly and accurately , And it can prevent the damage of electrical equipment and multimeter itself , Summarize a set of pithy formulas , as follows ：

· Check the block before measuring , Don't look, don't measure ;

· Measurement does not shift , Polarity is not reversed ;

· Resistance measurement is not electrified , Discharge before measuring capacity ;

· measuring  I It shall be connected in series , measuring  U In parallel .

● Oscilloscope

Oscilloscope , seeing the name of a thing one thinks of its function , It's an instrument that displays waveforms , It has always been designed by engineers 、 A good helper for debugging products , The earliest oscilloscopes were analog oscilloscopes , But now the market is mostly digital oscilloscope , One auto key , It's easy .
Digital oscilloscope is through analog-to-digital converter （ADC） Convert the measured voltage into digital information , It captures a series of sample values of the waveform , The discrete points are connected by interpolation algorithm and displayed , These discrete points can be stored , It can also be displayed after the waveform disappears , You can also do operations , Add, subtract, multiply and divide FFT wait .

● Digital bridge

Digital bridge is also called digital LCR Measuring instrument , Its measuring object is the parameter of impedance element , Including AC resistance R、 inductance L And its quality factor Q, capacitance C And its loss factor D.

● Signal generator

Signal generator is also called function signal generator , Can output sine wave 、 square wave 、 Triangle wave 、 Modulated signal , It's easy to use , But RF signal generator , We need to pay attention , Before outputting the signal , Impedance matching must be done well , Otherwise, the signal will reflect , It may damage the signal generator .

● Frequency meter

Frequency meter is an instrument for measuring signal frequency , It is widely used in various fields , It's easy to use , Needless to say .

● Vector network analyzer

Also called network analyzer , By synthetic signal source 、S Parameter testing device 、 The amplitude and phase receiver and the display part constitute , It is a common RF measuring instrument , It is mainly used to measure high-frequency devices 、 Performance parameters of circuit and system , Such as linear parameter 、 Nonlinear parameters 、 Frequency conversion parameters, etc .

● Spectrum analyzer

Spectrum analyzer is called spectrum analyzer for short , Mainly used to measure frequency 、 power 、 Frequency accuracy 、 Frequency stability 、 Phase noise 、 Harmonic suppression 、 Spurious suppression 、 Improvement factor 、 Signal-to-noise ratio 、 Spectral width, etc .

03 maintenance

First look at , Observe the whole with the naked eye PCB Circuit board , See if there is faulty soldering 、 Short circuit or lack of components , Then measure the power supply of each group with a multimeter , Confirm whether the power supply is short circuited to the ground . The next thing is power on , Confirm the input voltage before powering on , Then use a multimeter to measure whether the power supply voltage of each group is normal .

Last , You must have a certain understanding of the whole board , Divide the functions of the board into modules , From the phenomenon, judge which module has a problem , Disconnect the suspect module , To eliminate suspicious points .

If you have a good board in your hand , That would be more convenient , Directly measure the voltage or resistance to ground of each component , So in the process of maintenance , Multimeter is indispensable , But there are some complex and difficult problems , It is best to learn to use an oscilloscope .

04 debugging

debugging , Simply speaking , In order to realize all the functions we designed on the circuit board , Debugging is also one of the most valuable skills for hardware engineers to accumulate experience , Debugging skills need a solid theoretical foundation and long-term verification , The reason why I put it in the introductory chapter , I also want you to pay attention .

There are many debugging methods , As the case may be , Can't generalize , I have summarized the following common methods for your reference .

Generally, debugging starts with , before , I used to think that there was a lack of soldering 、 Short circuit and missing welding are the most easily found and solved problems in the commissioning process , But sometimes , It may take more than half a day to find these problems after debugging , So these more basic things , More noteworthy , Don't waste debugging time on this .

next , Find out how many groups of power supplies are on the whole circuit board , What chip powers and converts the power supply , Check each power supply step by step , Make them output normally , No problem with the power supply means that the hardware design is at least as successful , Then there are several key points for power debugging ：

· Before power on, measure whether each power supply is short circuited to the ground and connected reversely , Avoid burning the board .

· You can set the power indicator , If there is an indicator light that doesn't light up after power on , First, cut off the power and check .

· Measure the value of each power supply , And feel the temperature of the power supply device , Whether there is abnormal work .

After the power debugging is successful , Then you can debug the clock , The digital system relies on the clock to ensure that each chip can work orderly , First , To debug cpu The clock of , Then there is the bus clock , There are also clocks of various functional modules , The clock doesn't work , The corresponding modules cannot work properly , Sometimes normal operation should be high voltage pins , But it outputs low voltage , You can guess whether the clock doesn't work according to this phenomenon .

In fact, debugging comes down to two points ： Solid basic knowledge + As much practical experience as possible .

Correct hardware debugging consciousness and good debugging habits , It allows you to quickly solve hardware problems , After solving the hardware problem , Don't forget to look at some theoretical knowledge , Combination of theory and Practice , The understanding of the problem can be more profound .