Desperate Hacker

Chapter 340 Preemptive Real-Time Operating Systems and FPGAs
It was almost twelve o'clock at night.

Liu Yiqing was still busy working on the paper in the laboratory at this time.

As she approaches her PhD graduation, Liu Yiqing becomes even busier.

Only people who are studying for a Ph.D. understand that studying for a Ph.D. is a lonely thing.

About a year ago, Liu Yiqing focused her research on the rare lymphoma that Chen Qingfeng suffered from.

Because she found that Chen Qingfeng's medical records seemed to be of great research significance.

Most patients with Chen Qingfeng's disease will not survive for more than three months.

Because the cost of treating this disease is too high.

If nothing else, before there was Frotain, there were very few people who could receive heavy proton therapy, because not everyone could afford the cost of hundreds of thousands.

There are very few patients who can follow the doctor's guidance, and there are no specific drugs before.Therefore, there are very few valuable medical records that can be studied.

……

It can be said that Chen Qingfeng now lives not for himself, but for science and more patients with the same disease.

Liu Yiqing was writing Chen Qingfeng's case when she suddenly noticed Chen Qingfeng's birthday.

"It's actually tomorrow?"

Liu Yiqing took a look at the time and saw that it was already tomorrow.

Liu Yiqing picked up her phone by mistake and sent a message to Chen Qingfeng.

"Mr. Chen, happy birthday!"

……

Early in the morning, Chen Qingfeng's breakfast was a steaming bowl of hand-made noodles.

He told the chef in advance that he would make a whole bowl of it.So much so that when eating it in the morning, Chen Qingfeng was not even willing to bite it off.

I don't know if it was because he was one year older, but Chen Qingfeng found that his personality had changed.

Now he doesn't like the excitement, and because of his illness, he eats very simply.

After not looking at his phone for a night, Chen Qingfeng would have a lot of messages waiting to be processed.

Speaking of which, Chen Qingfeng is quite good at this.

People should learn to use tools to make themselves relaxed,

Chen Qingfeng used to use open source project management software to manage projects and use git to integrate code.Later, in the mobile Internet era, Chen Qingfeng used DingTalk again.

Thinking about it carefully, although Lao Xie was the boss in name, Chen Qingfeng had done everything from project development and customer communication to later payment collection. Lao Xie pushed all the problems onto him as the technical director. Now that I think about it, there are actually some skills that I can still use.

Of course he would not thank Lao Xie.

After dinner, Chen Qingfeng went to the Judgment Documents Online to check. Lao Xie was sentenced to five years for tax evasion, and it was still too early to get out!
……

Duke is in the United States, and there is a time difference with Chen Qingfeng, but this guy is a night owl, and he is always online whenever he is contacted.

"I spent a thousand dollars and got a drone used by the Yemenis!"

Chen Qingfeng didn't expect this guy to be so fast, but the other party was eager to take credit and quickly sent the photo over.

The drones used on the battlefield look similar to civilian ones. Duke demonstrated the control module of the bomb hanging under the drone.

Chen Qingfeng didn't care about these, he only cared about where these drones came from.

“There are no company trademarks or traces on the casing!”

"Can you take it apart and take a look?"

Chen Qingfeng wanted to see the control system of this drone.

There are many operating systems for drones, but most of them use open source mature systems uCos II, VxWorks, nuttX, etc.In this regard, Chen Qingfeng doesn't know the inside story of the industry, so he doesn't know whether domestic brands are also far ahead.

When ordinary people look at operating systems, they only look at the superficial visual interface.

For example, icon drag and drop, and other cool effects. Some manufacturers also refer to this part when they say they are completely independently developed.

What real engineers want to see is the core of the system.

For example, reading and writing of storage areas, compatibility of various modules, and CPU instruction sets.

The father of Linux, what he originally developed was just to output a and b alternately on the screen.

Everyone understands this kind of display, which means that the program he developed can implement two threads.

Therefore, the real operating system is by no means something that looks so cool, but is stable and combined with the internal hardware to do the work of some old scalpers.

The same goes for the drone’s operating system.

Different from the one used by ordinary mobile phones, drones use a preemptive real-time operating system.

Why is it a preemptive real-time operating system?

Because drones often encounter some emergencies in usage scenarios, such as unstable flight attitude.

At this time, what the CPU needs to deal with is not this kind of existing task, but to prioritize the flight attitude of the drone, which is an unexpected event.

These are two operating systems that are fundamentally different in terms of design ideas.

As Duke opened the drone's casing, Chen Qingfeng immediately saw the circuit and chip layout inside.

FPGA?
Chen Qingfeng did not expect that this drone used a programmable logic controller.

If this is the case, it is most likely not produced in Turkey, because the FPGA platform is not particularly stable for making drones as Chen Qingfeng knows.

Don't look at it now, it seems that everyone can rub a drone with their hands.Some people can even use four branches to build a drone frame.

But it is not that simple to apply this thing on the battlefield.

Simply put, the hardware of the drone mainly includes the flight control system, power system (motor, ESC, blades, battery), communication link, frame and other parts.

The flight control system integrates high-precision sensor components, mainly consisting of a three-axis gyroscope, a three-axis accelerometer, a three-axis geomagnetic sensor, a barometer, a GPS module, and a control circuit.

Some flight controls also have modules such as ultrasonic sensors (for precise control of low-altitude altitude or obstacle avoidance) and optical flow sensors (for precise determination of hovering horizontal position).

The core of the drone, the flight control system, can support fixed-wing, multi-rotor and helicopter flight control systems.

So many systems all use the CPU to process related information, so a stable drone development platform is necessary.

Common ones on the market include DJI development platforms, and there are also corresponding development platforms based on Qualcomm and Intel.

But for a blocked country like Persia, it is probably impossible to obtain chips for these platforms.

So they had to find another way.

Find a way from civilian FPGAs.

Previously, they used Siemens chips to manufacture uranium enrichment machines. Naturally, they can also find a way to use civilian FPGAs to manufacture drones.

But is such a system really stable?

Chen Qingfeng looked at this set of circuits and chips. While he was obsessed with the progressive Persians, he also instinctively had a hunch from an engineer's perspective that this thing should have many loopholes.

"Do you know reverse engineering?"

"I'm not familiar with hardware!"

Duke answered honestly:

"Let me teach you, let's see how those Persians put this set of things together out of thin air using a bunch of civilian components?"

(End of this chapter)