To prepare for my master’s application in 2021, I did some research on some of my favorite projects and summarized them here.

Ranking Source：QS2020, USNews2020, ARWU2019,csrank.global.2010-2020
The four rankings represent four perspectives (QS->UK，USNews->US，ARWU->China，csrank->cs Industry)

The following information section is taken from the Internet and may contain errors!!

UK

Imperial College London

QS: 9
USNews: 20
ARWU: 23
csrank: 73

Application mode:

Two choices. You can see your second choice when you are admitted.Applications can only be submitted once a year.

MSc Computing Science

• Fee£33,250
• 1 year

Condition

• A first class degree in any major
• Ielts 6.5 score 6/ TOEFL 92 score 20

Case

• con 85 (校友利)
• gre330 (优留)

MSc Applied Machine Learning

• Fee£32,500
• 1 year

Condition

• EEE first class
• Ielts 6.5 score 6/ TOEFL 92 score 20

UCL

QS: 8
USNews: 21
ARWU: 15
csrank: 50

Apply Method:

You can apply multiple times.The application is handled by the instructor and is not interchangeable between different departments.

MSc Integrated Machine Learning Systems

• Fee£28,530
• 1 year

Condition

• First class degree in EE/CS
• Ielts 6.5 score 6/ TOEFL 92 score reading and writing 24-30 listening and speaking 20-30

Case

• con 88 (校友利)
• 85 Telecom(优留)

MSc Computer Science

• Fee£30,400
• 1 year

Condition

• One second class degree in a non-CS major
• Ielts 7.0 score 6.5/ TOEFL 100 score reading and writing 24-30 listening and speaking 20-30

University of Edinburgh

QS: 20
USNews: 28
ARWU: 31
csrank: 33

MSc Computer Science

• Fee-
• 1 year

Condition

• First class degree in most engineering majors
• Ielts 6.5 score 6.0/ TOEFL 92 score 20

Case

• No case of admission, it is said that because of military industry related not to accept Asians

MSc Signal Processing and Communications

• Fee-
• 1 year

Condition

• EE and signal related major first class degree
• Ielts 6.5 score 6.0/ TOEFL 92 score 20

USA

Cornell University

QS: 14
USNews: 23
ARWU: 13
csrank: 7

M.Eng. Electrical and Computer Engineering (Ithaca)

• Fee$56,550
• Duration: one year (most extensions: one and a half years)

Condition

• 3.8 GPA
• the GRE 320 +
• IELTS 7.0/ TOEFL small say 22 Read 20 listen 15 write 20
• Two letters of recommendation

Case

• gre320，Strong scientific research

M.Eng. Electrical and Computer Engineering (NewYork)

• Fee$58,586
• 1 year

Condition

• GPA 3.8+
• GRE 320+
• IELTS 7.0/ TOEFL small say 22 Read 20 listen 15 write 20
• Two letters of recommendation

Carnegie Mellon University

QS: 48
USNews: 82
ARWU: 95
csrank: 1

Master of Science in Information Networking

• Fee$50,100
• 2 Years

Condition

• GPA 3.9+
• GRE 330+
• Toefl 102
• Three letters of recommendation

Case

• 宁诺85+gre326(优留)

Columbia University

QS: 18
USNews: 7
ARWU: 8
csrank: 15

Master of Science in Electrical Engineering

Condition

• GPA 3.7+
• GRE 320+
• the toefl 102
• Three letters of recommendation
• There might be an interview

Singapore

National University of Singapore

QS: 11
USNews: 34
ARWU: 67
csrank: 16

• Different colleges can apply for multiple majors

Master of Technology in Software Engineering

• FeeS$5,350.00
• 1 year
• Prefer people with work experience

Condition

• GPA 3.8+
• GRE 320+
• IELTS 6.0/ TOEFL 85
• the interview

Msc. Electrical Engineering - CE

• Prefer people with work experience

Condition

• GPA
• Ielts 6.0/ TOEFL 90

Msc. Computer Science

• Prefer those with work experience
• There may be restrictions on changing majors

Condition

• GPA 3.8+
• GRE 320+
  • IELTS 6.0/ TOEFL 90 (optional)

Nanyang Technological University

QS: 11
USNews: 43
ARWU: 73
csrank: 53

• Different colleges may apply for multiple majors

Msc Artificial Intelligence

• FeeS$58,000.00
• 1 year

Condition

• GPA 3.8+
  • IELTS 6.5/ TOEFL 100 (optional)

MSc Computer Control & Automation

• FeeS$3,350.00
• 1 year

Condition

• GPA 3.6+
  • IELTS 6.5/ TOEFL 100

Canada

University of Toronto

QS: 29
USNews: 18
ARWU: 24
csrank: 18

MEng. Electrical and Computer Engineering

• Length12-24months
• All Fee400,000 RMB/year

Condition

• GPA 3.6+
  • IELTS 6.5 score 6.0/ TOEFL 100 writing 22
• gre
  • Three letters of recommendation

Switzerland

Eth Zurich

QS: 6
USNews: 25
ARWU: 19
csrank: 10

• Switching majors is not friendly
• Undergraduate school is important
• There is a quota for each region

Master Electrical Engineering and Information Technology

• 1.5 year

Condition

• GPA 3.8+ (top 5-10%)
  • IELTS 7.0/ TOEFL 100
  • GRE 320+ (not mandatory)
  • Three academic letters of recommendation
  • Total tuition and living expenses are 200,000 to 300,000 YUAN
  • With a scholarship.

Federal Institute of Technology in Lausanne

QS: 18
USNews: 45
ARWU: 78
csrank: 28

• Only one major
• No regional quotas, global competition for applicants

Electrical and electronic Engineering

• 1.5 year
  • Switching majors is not friendly
  • Total tuition and living expenses are 200,000 to 300,000 YUAN
  • With a scholarship.

Condition

• 3.8 GPA
• IELTS 7.0/ TOEFL 100
• Three letters of recommendation
• GRE 320+ (not mandatory)

Migrated blog from Typecho to Hexo.

After reading Chairman Mao’s theory of practice and contradiction, it was the first time to systematically come into contact with the methodology of dialectical materialism, and I deeply felt its power and nature. Combining my own previous experience and understanding, I refined the view of cognitive derivation.

Preface

From Pavlov’s dog bell experiment[1] to Festinger’s cognitive dissonance theory in the 1950s[2], to the Stanford prison experiment led by Professor Zimbardo in 1971[3], this A series of psychology students’ physical experiments that broke expectations reveals step by step that the role of people’s psychology does not seem to be what most people think. In fact, this seemingly important psychological discovery was actually put forward by Marx, Engels and others from a sociological point of view two centuries ago and perfected it into a theory. Later, Lenin, Stalin and others improved it through practice. After being introduced to China, it was collected by Mao Zedong, combined with the heritage of Chinese traditional culture, and developed into Mao Zedong’s thought of materialist dialectics. The formation of this theory stems from these people’s summary of the social phenomena they observe and the social movements they practice based on the theory. And this reasoning guided the founding of the Communist Party of China and solidly completed the miracle of domestic capital accumulation.

Dialectical materialism is a set of self-consistent methodology, which can effectively guide our life practice, conclude the theory from practice, and then apply the theory to the process of practice. The efficient operation of this cycle is precisely the ultimate meaning of human cognition.

in conclusion

Methodology is a very effective and important tool. It provides people with a set of paradigms (habits) to help people practice the model of “social practice -> knowledge -> theory -> social practice” more effectively.

references

[1] 巴甫洛夫 - 维基百科
[2] 認知失調 - 维基百科
[3] 斯坦福监狱实验 - 维基百科

Share the improved version of fried chicken nuggets~

Material preparation

• Chicken breast
• An egg
• Chopped green onion and garlic

Preliminary steps

• Cut chicken into small pieces, add cooking wine, light soy sauce, starch, egg white, stir well and marinate for 10 minutes
• Chicken nuggets rolled in flour

Core steps

• Hot fried chicken nuggets until browned
• Vegetable oil minced garlic pot
• Add a spoonful of light soy sauce, a spoonful of white vinegar, a handful of sugar and ketchup
• Add chicken nuggets, so that the chicken nuggets are covered with sauce
• Sprinkle with chopped green onions

Finished picture

Before I went to Europe for a tourist visa, I had to buy a traveler’s cheque as a proof of funds because I did not have a three-month bank flow. However, when I arrived in Europe, I found that traveler’s cheques were difficult to use. If I didn’t understand the market, I would be defrauded of 15%-20% handling fees. This blog records the pits and Tips we found in redeeming traveler’s checks!

[scode type=”info”]Experience One: Do not use traveler’s checks if possible[/scode]
[scode type=”info”]Experience Two: The minimum handling fee for travel exchange is around 4%[/scode]

If you don’t want to see the experience, you can directly transfer to the Tips where you can redeem traveler’s cheques at the end of the article!

My experience

During the Christmas holiday, I went to Europe with my roommates and a group of four on a DIY trip to 5 cities in Italy and Austria. Since the UK bank card has not been used for three months, it is not possible to apply for a visa by printing the record, so we chose another method-buying American Express’s Euro traveler’s cheque. As everyone knows, exchanging and using traveler’s checks is really a big pit.

According to the official website of traveler’s cheques, traveler’s cheques can be used directly in shops in many European cities. In this way, it’s definitely more cost-effective to spend it when traveling than to exchange it back in British pounds after returning to the UK. The British pound process requires a loss of 8%). Ran goose, we found through reading other people’s travel notes before departure that many stores in Europe cannot directly spend traveler’s checks (according to our actual travel situation later, we only saw the traveler’s check logo in several stores in Venice), so we When I decided to go, I changed all of them to Euros at the Red Marked Change at the airport.

But after I found the red Change at the first stop in Rome (pictured), I found that 700 euros could only give us more than 590 euros. This is really not the slightest loss. My subject checked the phone number of American Express on the spot. I called it and found that there is no location in Italy, but the other party suggested to change to the bank, saying that there is no loss (note that this is also a pit,,,). Since two people have already exchanged them, in order to stop the loss, we decided not to exchange the 700 Euro traveler’s cheques of the remaining two people, and kept them to the bank for exchange.

On the third day, we went to the Vatican to play. By the way, we went to the bank recommended by the staff of American Express nearby. We also called the Bank of China, but we were all told not to accept travel. How can this be neat?

At this time, I just found a bunch of changes around the Vatican, so I asked for a quote again. One of them originally only reported more than 590, but we heard that the other offered us a student discount of more than 610, and then it was a good deal and reported a 640. This is great, we are beginning to discover the doorway inside: there are actually no discounts, but I want to find an excuse to attract you. These changes are all profitable. You give them your travel, and they sell them to American Express elsewhere. There may be a little tax in the middle, but as long as they charge you at a lower price than the tax deducted If you buy it here, he will definitely make a profit (generally, he will make a lot of money), but it’s just the difference between earning more and less. And there are several changes in the local area. We mainly found the one with red change and the one with blue. If this family thinks that you are demanding and unacceptable, then the money will be made by others.

Therefore, at this time, if we want to get a higher offer, we have to pinpoint what is acceptable to others (it’s really too cruel to cut off people’s wealth, then it’s okay), and then let them have a sense of crisis. Increase the offer. You can ask a few companies first to see how much they generally give, and then tell him how much other companies give me a price. Next, this person may start to call the above to see what a higher price can be offered, and after a bunch of them, they will give you a slightly higher price. Haha, if you are not satisfied, you can ask another one. Ask (but be careful, if it is a different store in the same store, be careful, after all, there may be one person above them, maybe I will remember you). Generally speaking, if you say that the tax may be two or three percent, then you still have to earn a 20 or 30 pounds. (Of course, you can try to chop and chop again, but it may be more difficult. Big).

So our last two transactions were 640 Euros and 645 Euros respectively (645 Euros were replaced by a similar method).

Tips

• There are not too many places in Italy for travel and consumption. Among the Rome, Florence, and Venice we go to, there are only a few in Venice;
• If you want to exchange for Euro travel in Italy, you can only change it at the place marked with the change sign (Of course, some changes do not accept travel, but very few). There should be no direct exchange points for American Express, at least in Italy, so there is no way to exchange them without loss. But there are indeed many changes in Italy, especially near the Vatican;
• Don’t meet a family, if he quotes a very low price, you will accept it, and don’t believe him too much. You must know that this is probably because you don’t know the inside story;
• You can ask two families first to find out the situation. A rough estimate. If the tax may be two or three percent, then you still have to make people earn 20 or 30 pounds. First ask them for their quotation. You can say that the price is given to you by another family. Ask if they can give you a higher price. Of course, if you have a thin skin and are embarrassed to talk nonsense, you can just give them the price of this one when the price is lower than that of others.

to sum up

The above is all the personal experiences and small tips about the exchange of travel expenses. Of course, these are just some things summarized based on our personal experience, we still need to analyze the specific situation. If you want to go out and play, you still want to walk around more to see how you feel. Therefore, it is not recommended that you waste too much time on this matter when economic conditions permit, as long as you feel that it is almost acceptable. Finally, I still want to say that if you don’t need traveler’s checks to play in Italy, you should not use it. After all, it is really troublesome and there are pits everywhere!

Activate win10 Home Edition, Professional Edition, Enterprise Edition, Education Edition with one click φ(￣∇￣o)

Method one (automatic installation)

• To use this method, please close all antivirus software
• To use this method, please close all antivirus software
• To use this method, please close all antivirus software

p.s. If you are not assured, please use Method Two-Source Installation

• Click here to download the exe program

• Run the program you just downloaded. (Please do not modify the decompression path)
• Run the program you just downloaded. (Please do not modify the decompression path)

• Click More info -> still running

• Enter numbers to select. (You can enter the number 4 to get a Chinese translation!!)

• Wait patiently for the activation to complete~ ::aru:proud::

The script has been sent to the desktop kms.bat, you can delete it if you don’t need it~

Method two (source installation)

• Click here to download the compressed file.

• Unzip the compressed file (please unzip, otherwise it will not run)
• Unzip the compressed file (please unzip, otherwise it will not run)
• Unzip the compressed file (please unzip, otherwise it will not run)

• Double-click kms or kms.bat in the run folder.

• Click More info -> still running

• Enter numbers to select. (You can enter the number 4 to get a Chinese translation!!)

• Wait patiently for the activation to complete~ ::aru:proud::

Advanced

Activation code

Your activation code will be saved in C:\Windows\kms.key

Run log

• Activation log %temp%\kms.log
• Tried activation code %temp%\kms.tried_keys on this machine
• kms server configuration %temp%\kms.skms
• ato output information %temp%\kms.ato

Restore inactive state

• Enter kms.bat and select 3
• Wait for the uninstallation to complete! ! !

Source code

• Project address: iotcat/kms

Deploy your own new coronavirus API in one minute ୧(๑•̀⌄•́๑)૭

coro-api

Novel coronavirus real-time data api
Project Git address: iotcat/coro-api
Project npm address: iotcat/coro-api

API example

Get all

https://api.yimian.xyz/coro

According to province

https://api.yimian.xyz/coro?province=Shandong

According to the city

https://api.yimian.xyz/coro?city=泰安

According to the province and city (recommended)

https://api.yimian.xyz/coro?province=Shandong&city=Taian

Quick deployment

Environmental requirements

• nodeJS supports any version of express
• Any version of git

download file

1

$ git clone https://github.com/iotcat/coro-api.git & cd coro-api

Installation dependencies

1

$ npm install

start up

1

$ node index.js

Access

1

http://localhost:17676

Advanced

GET parameters

Modify port

Modify the default port from line 9 of index.js.

Cross-domain prohibited

Comment out line 13 of index.js.

Use pm2 daemon

1
2

$ npm i -g pm2
$ pm2 start index.js --name coro-api -o /var/log/coro/api.out -e /var/log/coro/api.err --watch

Nginx configuration

Add the following content to server{}

1
2
3

location / {
    proxy_pass http://127.0.0.1:17676;
}

If you are not mapping from the root directory, remember to go to the 11th line of index.js and change app.get('/', f) to your path.

Crawler configuration

The crawler uses coro-py, please refer to its documentation.

Open Source Agreement

This project uses the MIT protocol, allowing non-signed commercial and non-commercial use. Go Wuhan! Go China! ! ❤

Self-developed spicy beef noodle practice~

Material preparation (for two persons)

• Noodles
• Two eggs
• Two British scallions, minced
• Two slices of ginger minced
• Dice beef
• Prepare a small bowl with anise, cinnamon, white button, and a little white pepper

Preliminary steps

• Hot pot vegetable oil fragrant fried eggs
• Blanch the beef in hot water

Core steps

• Hot pot vegetable oil sesame oil, put the scallion part into the pot
• Add boiling water and beef cubes, add the seasoning in the bowl, and simmer for 3 minutes
• Add a spoonful of light soy sauce, half a spoonful of dark soy sauce, and a spoonful of oyster sauce
• Add appropriate amount of chicken essence and salt to adjust fresh
• Add appropriate amount of red vine pepper oil to adjust spicy
• Add the noodles and cook until cooked

Follow up

• Add the noodles to the bowl and cover with eggs
• Add the remaining green onion

With pictures

I studied in the UK, traveled to Europe on Christmas, and DIYed an Italian Schengen visa. Now come back from the tour, summarize a Schengen sign strategy.

General process

• Read Official Website conditions carefully to check whether you meet all the requirements
• Online Interview Appointment online as early as possible (the time can be modified later)
• Carefully study the required materials (must follow the official website)
• Generate visa application form (Online generation)
• Prepare other materials

Material category

Regular visa materials

• Visa application form
• personal I.D
• Proof of residence
• Photos

Additional visa materials

• Proof of employment
• Proof of property
• Travel certificate
• Proof of accommodation
• Insurance certificate

Material CheckList

• Original visa application form (print after online generation)
• Original passport + photocopy (black and white)
• BRP original + copy (black and white)
• A passport photo-consistent with the UK visa (Requirements)
• student letter
• Original traveler’s check + copy or three-month bank account
• Round-trip air ticket (name, date, to&from)
• Train ticket (name, date, to&from)
• Proof of accommodation (name, date, address)
• Companion list
• Travel insurance certificate (name, geographic area, insurance amount)
• Copy of appointment certificate

• Travel itinerary (for easy explanation with visa officer)
• joint travel confirmation letter (if your name is not on a certain ticket or accommodation certificate)
• Copy of the passport signature page of the ticket purchaser (if your name is not on the ticket or accommodation certificate)

Material Description

visa application form

• After filling out the first page online, remember to click SAVE, and write down the Reference Number ::aru:shy::
• Click RETRIEVE INCOMPLETE FILLED VAF above to continue to fill in after logging in next time
• Fill in the reference this guide
• Single-sided black and white A4 printing
• After printing, do not fill in, do not sign, do not post photos, the visa officer will tell you what to do
• Do not staple, it is recommended to use a loop pin

Student Letter

• Go to school FB to open
• A signature is required, and an electronically printed signature will not work
• Head up to write Italy Consulate

Travel Proof

• Need to provide paid air tickets and inter-city train tickets
  • A website link is required at the bottom of the ticket
• All tickets need to have your name
• If a ticket does not have your name, the person named on the ticket is required to provide a signed joint travel confirmation letter and a copy of passport
• Please refer to our joint travel confirmation letter
  

Proof of Accommodation

• paid is required on Booking Confirmation
• A website link is required at the bottom
• All materials need to have your name
• If you do not have your name, the person who has the name needs to provide a signed joint travel confirmation letter and a copy of passport
• It is recommended to order from well-known websites such as Booking

Insurance Certificate

• Be sure to cover the journey
• The longer the guarantee period, the longer the visa period. .
• We chose Taiping Insurance Schengen emergency visa for reference

Appointment Proof

• Go to the front desk downstairs to register with the appointment letter
• After that, the appointment letter is useless

Results

Finally, let me show the visa I got~

Leave a blank here first, then fill it in slowly~

φ(￣∇￣o)

In order to more clearly and intuitively choose the apartment to live in next year, this article summarizes the evaluation information of each apartment on the Internet for decision-making reference.

[scode type=”green”] Everyone is actively adding in the comment area, comments recommend using qq mailbox[/scode]
[scode type=”yellow”]Continuously updating…[/scode]
[scode type=”blue”]I hope you can add more listings for investigation[/scode]

All walking distances are centered on Guild! !

Dover Court (Our final choice)

• walking distance: 8 min (Northwest)
• google map: Dover Court
• Official Guide: Dover Court
• Pros: Close to Lidl, quiet, well managed, safe, cleaned regularly, good social place, quiet study room downstairs
• Disadvantages: Room soundproofing is average, some rooms are small, and some places have low ceilings
• Price: ￡155.54 pw (Last Year)

Horizon Heights

• walking distance: 14 min (West)
• google map: Horizon Heights

St Luke’s View

• walking distance: 13 min (southwest)
• google map: St Luke’s View

Apollo Court

• Walking distance: 11 min (Northwest)
• Classmates' reflections: Not quiet (Lao Lei)

Capital Gate

• walking distance: 7 min (Northwest)

Grand Central

• walking distance: 12 min (West)

Philharmonic Court

• Walking distance: 12 min (South)

The Railyard

• walking distance: 9 min (East)

Myrtle Court

• walking distance: 9 min (East)

Larch House

• walking distance: 7 min (West)

IQ

• walking distance: 9 min (Northwest)
• Connection: Lao Ye, Bulb

The Arch

• walking distance: 18 min (southwest)

Albert Court

• walking distance: 10 min (north)

St Andrews Place

• Walking distance: 10 min (Southwest)

The Ascent

• walking distance: 13 min (West)

Lee Court

• walking distance: 10 min (north)

X1 Liverpool One

• walking distance: 18 min (West)

X1 The Edge

• Walking distance: 12 min (Northwest)
• Others: Express can be sent to Cambridge Court (Liang Bin)

Cambridge Court

• walking distance: 8 min (south)
• google map: Cambridge Court
• Disadvantages: Poor sound insulation, damp carpets, poor conditions

Vita Student Liverpool

• walking distance: 21 min (West)

Liberty Park

• Disadvantages: Sound insulation is not good on the first and second floors
• Advantages: There is a small garden in the middle of Huizi Building (Jiaojiao, Xinyi)

I studied in the UK and shared with 4 roommates. In order to better control and monitor public expenditures and maintain the balance of public expenditures between each other, I designed and developed this ERP public expenditure planning system during the welcome Wednesday. I hope that this system will make life easier for the next year, reduce conflicts between everyone, and promote the sustainability of public expenditure projects full of happiness OωO

1. Function introduction

• Calculate the daily average weekly flow rate to visualize public expenditure
• The user declares a public expenditure and submits the invoice photo certificate
• Monitor the disequilibrium of expenditure among members, calculate the variance, and display it visually
• Compare spending this week and last week, and give the percentage increase or decrease
• When there is one person whose expenditure exceeds the average threshold, and there is at least one person whose expenditure is less than the average threshold, the two people will be emailed to generate an internal transaction
• When the recipient receives the money in the above example, he needs to go to the platform to confirm receipt
• All historical public expenditures and invoices on the platform can be checked

2. System Architecture

2.1 Frontend

The front end is based on a Bitcoin website platform template found on the Internet, and a deep transformation is realized. It is worth mentioning that the front end uses Ushio-js project as a security and logging plug-in, and got Ushio The system does behind the scenes.

2.2 Backend

The backend is written in php language. Provides 5 interfaces, which respectively provide the functions of obtaining account events, obtaining internal circulation information, obtaining public expenditure information, obtaining weekly statements, and operating.

The mail system is quickly constructed using Yimian Mail API.

2.3 Database

The database uses yimian-db/mysql. Three tables are constructed, which are used to store flow, public expenditure details, and internal circulation.

2.4 Image upload

Directly quote the code of 呓喵酱の图床 with a small amount of rewriting.

2.5 User System

At present, it is simple to implement with additional web pages, waiting for the ushio-auth project to complete the unified integration.

3. Appearance

Nothing to say, show the picture, see for yourself

Based on Home Assisstant, build a smart home with integrated home lighting system, multimedia system and water flow system. Technical points: Tmall Genie interaction, LoRa communication, MQTT protocol, FRP intranet penetration, NAS storage, and toggle switch circuit transformation.

Combining the knowledge I have learned and using cutting-edge technology to benefit life has been my unremitting pursuit for a long time. In order to let my family experience a more stable, comfortable and intelligent lifestyle, and to consolidate the technical foundation and architecture experience accumulated in the school smartfarm project and my own ushio system, I decided to use 20 to 23 before going abroad. All day long, reconstruct the old IoT system at home. Adopt a layered architecture and interface-oriented, test-oriented, and document-oriented development principles, with Available and Reliable as the highest priority indicators to build an operational target 3. A highly modular, easy-to-remote control, open source home software and hardware intelligent sensor control system for more than years.

0 Architecture overview

1 Hardware Design

1.1 Single Chip Microcomputer Material Selection

Use Arduino UNO as the calculation unit. On the one hand, Arduino Uno has high reliability. My previous smart curtain system used Arduino Uno as the main control board, and it ran smoothly for one and a half years without hardware problems. On the other hand, Arduino Uno has a larger RAM, so there is no need to bother to program the microcontroller in order to compete for RAM.

The main disadvantage of Arduino UNO is its high price, but this cost is necessary to ensure long-term stable operation.

1.2 WiFi communication module selection

Use ESP-01 as the WiFi communication module. The main reason is that the ESP-01 has been used to build a remote control car in the previous school courses, and I have a better understanding of its working methods and performance to reduce development costs.

1.3 LoRa communication module selection

Use Anxinke LORA RA-02 LORA as the communication module between LoRa node and LoRa gateway. The reason is that this module is used in the surf project, so I understand it better.

1.4 Smart speaker selection

As the most important interface for human-computer interaction in this Internet of Things system, smart speakers play a pivotal role. After research, I use Tmall Elf Sugar R as a home smart speaker. On the one hand, the price/performance ratio of Tmall Genie is very cheap. Second, unlike Xiaomi’s development of Xiao Ai, the purpose of Ali’s development of Tmall Genie is to provide a platform that allows developers to access its network in various forms, which is very important to me.

1.5 Light toggle switch

Initial idea: one-way control + reset device.
Actual realization: The original single-opening is transformed into double-opening, one is connected in series with the relay, and the other is connected with two pin ports.

2 Communication Design

Two communication modes of WiFi+LoRa are adopted. In scenarios that require high-speed and high-quality communication, such as Tmall Genie, mobile phones, and notebooks, use WiFi as a means of communication. In places where the WiFi signal is unstable, use LoRa for communication. Use MQTT as the application layer protocol.

3 Main control system design

Use the python3 open source project Home Assistant as the basis to build the main control system of this project.

4 Multimedia system design

Multimedia is mainly provided by Tmall Genie. In addition, through the Xiaomi box, the video, pictures, and music in the home network disk can be played on the TV and stereo.

5 Cloud support system design

dns.yimian.xyz provides dns resolution service.

6 NAS storage system design

By mounting the idle 500G mechanical hard disk removed from the old computer to the old IBM server, the storage system is built.
In the local area network, since the home is a win system, smb is used as a sharing protocol to realize file transfer and supports mounting in the local area network. The speed is stable, and the whole network reads and writes about 10MB/s. Access to the external network is realized through http and frp reverse generation, but the speed is slow.

2020.6 update

RNN realizes light control

Based on the previously accumulated human sensor data, the LSTM model is used to train the neural network using keras to realize the prediction of the light state.

This article introduces in detail the design ideas, implementation status and defect reflections of the SmartFarming Proj IoT architecture of XJTLU University’s 2019 summer scientific research.

1 Background

1.1 Requirements

In order to explore the feasibility of agricultural Internet of Things technology, instructor Alam Mohammed hopes that we can provide a Available and Reliable Internet of Things system to realize intelligent monitoring and management of farmland. This system will be able to timely detect the parameters related to plant health in the soil and the air, process and store these data (proposed by Alam). At the same time, the automatic control irrigation function (proposed by Caleb) and some data display methods (optional requirements proposed by Alam) are also expected to be provided by this system.

1.2 Positioning

As it is a small scientific research project designed for the agricultural Internet of Things, the goal of the project is to explore the feasibility of the agricultural Internet of Things, and the vision is to simulate the most common small-scale agricultural Internet of Things application scenarios. Therefore, the positioning of this architecture is ** applicable to most small agricultural IoT projects with sensing, control and display functions**.

2 Glossary

• MQTT: MQTT Message Queuing Telemetry Transport is a message protocol based on the publish/subscribe paradigm under the ISO standard (ISO/IEC PRF 20922). It works on the TCP/IP protocol suite and is a publish/subscribe message protocol designed for remote devices with low hardware performance and poor network conditions [1].

• LoRa: LoRa is an emerging technology in the current market, which operates in the public frequency band below 1 GHz for long-distance low-power communication [2].

3 Design goals

3.1 Implementing functions

The functional requirements of this architecture mainly include land data collection, weather data collection, irrigation system control, interaction with the drone group system, web console (can view real-time and historical sensor data, index data; be able to control the system).

3.2 Performance indicators

• Communication range (test): the radius is not less than 1km
• Communication range (production): the radius is not less than 3km
• Delay: average less than 1s
• Timeout rate: no more than 5%
• Resource occupation: Node RAM does not exceed 2k
• Run cycle: 1 minute (test) | 15 minutes (production)

4 System Environment

4.1 Related software and hardware

!!!

4.2 Data size estimation

According to the production scenario, a data set is generated every 15 minutes, and a data set occupies about 253-291 bytes. According to 291 calculation, 27.93KB of data will be added every day.

5 Design Ideas

5.1 Idea

• Document-oriented
• Interface-oriented
• Test-oriented

5.2 Key Issues

• Land node RAM resources are scarce, only 2K
• LoRa communication adopts 433MHz, single-channel transceiving, much interference
• The server needs to collect and aggregate hash data from multiple nodes
• Reserve a method of interaction with the drone AI team
• Push real-time messages to the front-end browser

5.3 Scheme selection

In order to prioritize to ensure the stability and scalability of communication and services, we select layered model as the design mode of the architecture. The entire system is divided into multiple levels, with necessary interactions between levels. Each level runs independently, restarts quickly when it crashes, and has a high degree of reliability.

In terms of safety, the method of internal and external network isolation is adopted. Taking into account the scarcity of computing resources of some devices in the intranet, the interaction with the intranet server adopts an unencrypted communication mode. The intranet server interacts with the cloud server through SSL encryption. To ensure the security of the client’s data, the cloud server API only accepts HTTP and WebSocket requests with SSL encryption.

6 Architecture Design

6.1 Basic introduction

The main purpose of this architecture is to provide a stable (Available) and reliable Internet of Things system, which collects real-time data in farmland, combines pictures collected by drones and judged by CNN Plant health, realize intelligent management of irrigation system and plant health. This framework is theoretically suitable for most farm environments. The test environment is within a radius of 2~5km (depending on the antenna), and the wind is below level 3. This system acquires farmland data through sensors, controls the irrigation system through transistor circuits, relays, etc., and interacts with managers through web pages and APIs.

6.2 System hierarchy diagram

This figure shows the abstract hierarchy of this architecture. As pointed out, this layered architecture can be clearly defined as the perception layer, network layer, application layer, three horizontal operation layers, and a vertical error handling layer.

Among them, the perception layer can be further refined into environment layer and hardware layer. The environment layer contains plants, soil, air, water and other natural objects that we want to detect and control. The hardware layer provides the underlying technology for the system’s interactive behavior (detection, control) of natural elements through artificial electrical devices such as sensors and controllers. Sex. When the perception layer realizes the interaction of natural information, the corresponding digital information is transmitted to the network layer for communication. Correspondingly, the perception layer will also receive corresponding control information from the network layer, and make corresponding control actions according to these instructions.

Network layer is divided into three layers. The lowest layer is the preprocessing layer. Its main task is to package the data collected by the perception layer and transform it into a form suitable for network circulation, such as sockets. Therefore, the pre-processing layer requires a small amount of computing storage resources, such as a single-chip microcomputer, EEPROM, etc. After encapsulation by the preprocessing layer, the data is transmitted to the physical layer. Based on devices such as gateways and routers in the physical layer, these data packets can be distributed and transmitted in an orderly manner. The application of the MQTT protocol in the communication layer makes the management of these data packet distribution more efficient and convenient. In addition, the implementation of the QoS service quality detection system in the communication layer also makes the performance of the network layer more fault-tolerant and reliable.

Application layer is mainly responsible for some application-level services for business logic, such as data analysis, event processing, etc. At the bottom of the application layer, the service layer is running for a long time. The service layer is the closest part of the application layer to the network layer. Its main purpose is to process the incoming data from the network layer in real time and respond quickly to corresponding requests and error events. At the same time, the service layer is also responsible for sorting and analyzing the data collected by the sensors and passing it to the database layer for storage. In order to ensure the reliability of the service, the implementation program of the service layer is registered as a system service and guarded by a special daemon. Unlike the long-term operation of the service layer, the business layer is invoked on demand. When a new request comes in from the interface layer or a specific event occurs in the service layer, the business layer will be called and processed. In addition to some basic data analysis, the business layer also has the authority to make analysis requests to the AI ​​layer. AI layer After analyzing the image data returned from the drone, it will send back a judgment result to the business layer. According to the specific content of the request, the business layer will organize the image recognition results, historical sensor data, etc., and pass them to the interface layer. Interface layer is mainly used to provide different forms of interfaces, such as HTTP interface and WebSocket interface, to facilitate client calls.

6.3 System Topology Diagram

From the topological structure, as shown in the figure above, the entire system can be physically divided into land nodes, weather nodes, LoRa gateways, intranet servers, cloud servers, databases and user terminals.

From the perspective of functional mechanism, the entire system includes: sensor module, LoRa communication module, LoRa gateway module, MQTT-Proxy proxy module, water pump control module, MQTT+ data processing module, web interface module, daemon module and database module.

Land Node
Land nodes are deployed in farmland in different regions to detect soil temperature and humidity parameters, and can provide control of water flow solenoid valves at corresponding locations. The land node uses Arduino Nano as the computing unit, uses LoRa as the communication method to connect to the LoRa gateway (and other nodes), and uses battery power. Its large number, harsh working environment and unstable wireless communication are the biggest source of uncertainty in the system.

Weather Node
Meteorological nodes are deployed at specific locations in farmland to detect meteorological parameters such as air temperature, humidity, atmospheric pressure, rainfall, light, NH3 concentration, and CO concentration. The weather node uses Arduino Nano as the computing unit, uses LoRa as the communication method to connect to the LoRa gateway (and the land node), and uses battery or wired power. The working environment is harsh and the wireless communication quality is average.

LoRa Gateway
The LoRa gateway is deployed indoors. In order to expand the effective communication radius, its antenna can be extended outdoors. The LoRa gateway connects to various land nodes and weather nodes through LoRa, and connects to the intranet server through WiFi. The LoRa gateway can convert the socket packet incoming through LoRa into an mqtt message and pass it to the intranet server, and convert the mqtt message from the intranet server into a socket packet and send it to the designated node through LoRa.

Intranet server
The intranet server is a Raspberry Pi 3B, which contains three functional modules: MQTT-Proxy proxy module, water pump control module and daemon process module.

MQTT-Proxy proxy module can receive the mqtt message sent by the LoRa gateway via WiFi, encrypt it with SSL and forward it to the cloud server. At the same time, the MQTT-Proxy proxy module will also accept the specified mqtt message from the cloud server, decrypt it and forward it to the LoRa gateway.

Water pump control module The state of the water pump is controlled through a relay through the GPIO of the Raspberry Pi. The mqtt communication with the water pump control module directly communicates with the cloud server without passing through the MQTT-Proxy proxy.

Daemon module runs on Linux and is used to monitor the MQTT-Proxy proxy module and the water pump control module. When modules are detected to stop running, the daemon module will restart these modules in time to ensure the stability and continuity of services.

Cloud Server
The cloud server runs on Huawei Cloud located in Beijing and includes MQTT+ data processing module, web interface module and daemon module.

MQTT+data processing module includes the Service layer and the Business layer in the hierarchical structure. This module communicates with the intranet through mqtt, and interacts with the web interface module (and AI module) through mqtt and redis. After receiving various hashed data from the intranet, this module will automatically aggregate them, organize them into one piece of data, store it in the database, and push it to the web interface module through redis. In addition, this module will periodically send requests to each node to obtain their data, and these requests will be tracked to calculate the delay.

web interface module provides a series of HTTP and WebSocket interfaces. These interfaces can be used to get data, send instructions, refresh data, and get push messages.

Daemon module runs on Linux and is used to monitor MQTT+ data processing module and web interface module. When modules are detected to stop running, the daemon module will restart these modules in time to ensure the stability and continuity of services.

7 Module description

7.1 LoRa communication module

The LoRa communication module is used to realize stable and reliable socket communication in a single channel. This module includes LoRa-socket and LoRa-mqtt.

LoRa-socket encapsulates data packets on the basis of LoRa-Arduino, realizes simple udp and tcp communication, and makes traditional LoRa communication more reliable. By adding the sending and receiving ip address to the head of the data packet, and adding the hash check value at the end of the data packet, LoRa-socket supports point-to-point communication and broadcast communication, and has powerful noise processing capabilities and data tamper resistance.
Project address: iotcat/LoRa-socket

LoRa-mqtt is a simple reproduction of the mqtt protocol based on LoRa-socket. Based on udp and tcp, LoRa-mqtt supports mqtt communication with qos 0 and 1.
Project address: iotcat/LoRa-mqtt

7.2 MQTT-Proxy proxy module

This module runs on the intranet server and realizes the encrypted forwarding of the intranet mqtt.
Project address: iotcat/sf-mqtt-proxy

7.3 Water pump control module

This module runs on the intranet server and realizes the control of the relay water pump through GPIO.
Project address: iotcat/sf-pump

7.4 mqtt+data processing module

This module runs on the cloud server and realizes the data aggregation, processing and storage of the underlying mqtt messages.
Project address: iotcat/sf-mqtt-broker

7.5 web interface module

This module runs on the cloud server and realizes the provision of functional interfaces.
Project address: iotcat/sf-web-api

8 Development Document

8.1 mqtt theme

• mqtt topic list

8.2 http interface

• httpinterface document

8.3 websocket interface

• websocket interface document

9 Running status

9.1 System delay

The figure above shows the line graphs of the delay statistics of the land node (left), the weather node (right), and the water pump (bottom). It can be seen from the figure that the average delay of the land node is about 730ms, the delay of the weather node is about 900ms, and the delay of the water pump is relatively low, about 45ms.

9.2 Sensor data

Click here to view the weather sensor data of 2019-7-31

Reference List:

[1] OASIS, (2015,12.10). MQTT Version 3.1.1 Plus Errata 01 [Online]. Available: https://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt -v3.1.1-errata01-os-complete.html

[2] Sinha, R.S., Wei, Y. and Hwang, S.H., “A survey on LPWA technology: LoRa and NB-IoT”, in Ict Express, 3(1), pp.14-21, 2017.

Recently, I have used Arduino to build LoRa gateways and nodes in the development of the Internet of Things, and I found that some strange phenomena are always encountered when calling String. After investigation, it was found that it was caused by overloading of the []= operator elsewhere.

For convenience, we used LoRa-Socket and ArduinoJSON as dependencies when developing nodes. We found that these two dependencies perform well when used separately, but if used in the same project file, it will cause some weird problems.

Situation One

When calling a function through a pointer, the String parameter passing is abnormal. code show as below:

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inline static void _onReceived(const String& msg, const String& from, const String& to, const String& type){
    (*_f)(msg, from, to, type);
};

In this case, we found that the value of msg and other String in this function is all normal, but it was not successfully passed to _f. After a series of Sao operations, we come to the following conclusions:

• Found that if you change String to int or other types, the parameters passed to _f are all normal. Only the String and char types are problematic.
• We tried to convert String to other types, and then back, but to no avail.
• The declaration of global variables of type String or char will crash the microcontroller.
• When we delete the ArduinoJSON dependency, the passing of String parameters is normal.

We can conclude that this strange phenomenon is caused by the conflict with the ArduinoJSON package.

Situation Two

When using ArduinoVector to make a String type Vector, we also discovered the instability of the String type. The magic is that this phenomenon only occurs in the use of String, other types such as int work well.

These instabilities can be summarized as follows:

• Truncated during assignment
• String values ​​are locally out of order
• Part of the String value is garbled
• It will fail when passed as a parameter to the function, and it will be empty (similar to case 1)

Summary

Through the above two cases, we can preliminarily conclude that this is due to the conflict between the overload of the []= assignment operator and String. As long as you use []= to redefine String, string weird problems may occur.

This API is based on Huawei Cloud Object Storage and uses Huawei CDN Cloud acceleration. The global average download speed is 10MB/s. The API has included 1100+ two-dimensional pictures, 20+ Bing wallpapers (automatically captured daily), 150+ two-dimensional avatars, and 10+ pictures uploaded on the bed.

This API does not promise permanent maintenance, please be sure to consider use risks before use! !

1 API address

• https://api.yimian.xyz/img

2 Quick start

Random two-dimensional picture

• GET/POST /img?type=moe
• Example: https://api.yimian.xyz/img?type=moe

Random Bing Wallpaper

• GET/POST /img?type=wallpaper
• Example: https://api.yimian.xyz/img?type=wallpaper

Random two-dimensional avatar

• GET/POST /img?type=head
• Example: https://api.yimian.xyz/img?type=head

Random bed pictures

• GET/POST /img?type=imgbed
• Example: https://api.yimian.xyz/img?type=imgbed

Random 1920x1080 size two-dimensional picture

• GET/POST /img?type=moe&size=1920x1080
• Example: https://api.yimian.xyz/img?type=moe&size=1920x1080

3 Parameter list

4 Detailed parameters

4.1 type

Two-dimensional (default)

• GET/POST /img?type=moe
• Image source: Daily Collection of Miao Miao Jiang (Pivix, Twitter)
• Example: https://api.yimian.xyz/img?type=moe

bing daily wallpaper

• GET/POST /img?type=wallpaper
• Image source: Bing Daily Wallpaper
• Example: https://api.yimian.xyz/img?type=moe

  Automatically updated daily

Two-dimensional avatar

• GET/POST /img?type=head
• Image source: Selectively intercepted from two-dimensional images
• Example: https://api.yimian.xyz/img?type=head

Miao meow sauce picture bed

• GET/POST /img?type=imgbed
• Image source: 呓喵酱图床
• Example: https://api.yimian.xyz/img?type=imgbed

こいぬちゃん

• GET/POST /img?type=koino
• Image source: @九条だんぼ (Twitter, Pivix, Google)
• Example: https://api.yimian.xyz/img?type=koino

EasyVer man-machine verification

• GET/POST /img?type=easyver
• Image source: Optimized finishing
• Example: https://api.yimian.xyz/img?type=easyver

4.2 display

If this parameter is set to true, 302 jump will be disabled and the complete picture encoding will be returned directly. This method is very low and slow. Please use it carefully.

false (default)

• GET/POST /img?display=false
• Description: 302 Jump to return to the picture, recommended
• Example: https://api.yimian.xyz/img?display=false

true

• GET/POST /img?display=true
• Description: Return to the picture directly, slow
• Example: https://api.yimian.xyz/img?display=true

4.3 size

Use this parameter to limit the image size. This parameter supports the following formats:

??x??

• GET/POST /img?size=??x??
• Description: width x height
• Example: https://api.yimian.xyz/img?size=1920x1080

??x*

• GET/POST /img?size=??x*
• Description: width x any height
• Example: https://api.yimian.xyz/img?size=1920x*

\x??*

• GET/POST /img?size=*x??
• Description: Any width x height
• Example: https://api.yimian.xyz/img?size=*x1080

\x**

• GET/POST /img?size=*x*
• Description: any width x any height (default)
• Example: https://api.yimian.xyz/img?size=*x *

??-??x??

• GET/POST /img?size=??-??x??
• Description: width range x height
• Example: https://api.yimian.xyz/img?size=1910-1930x1080

??x??-??

• GET/POST /img?size=??x??-??
• Description: width x height range
• Example: https://api.yimian.xyz/img?size=1920x1070-1090

??-??x??-??

• GET/POST /img?size=??-??x??-??
• Description: width range x height range
• Example: https://api.yimian.xyz/img?size=1910-1930x1070-1090

??-??x*

• GET/POST /img?size=??-??x*
• Description: width range x any height
• Example: https://api.yimian.xyz/img?size=1910 -1930x*

\x??-??*

• GET/POST /img?size=*x??-??
• Description: Any width x height range
• Example: https://api.yimian.xyz/img?size=* x1070-1090

4.4 range

This parameter specifies the allowable size error, which needs to be used with size, and the default is 0.

For the?? type size parameter

• GET/POST /img?size=??x??&range=100
• Description: width ±100 x height ±100
• Example: https://api.yimian.xyz/img?size=1920x1080&range=100

For??-?? type size parameter

• GET/POST /img?size=??-??x??-??&range=100
• Description: Min width-100|Max width+100 x Min height-100|Max height+100
• Example: https://api.yimian.xyz/img?size=1910-1930x1070-1090&range=100

For *type size parameter

• GET/POST /img?size=*x*&range=100
• Description: Invalid range

4.5 id

Each category has its own id system, and different image ids under the same category are unique.

*Two-dimensional *

• GET/POST /img?type=moe&id=15
• Description: Extract the two-dimensional image with id 15
• Example: https://api.yimian.xyz/img?type=moe&id=15

bing daily wallpaper

• GET/POST /img?type=wallpaper&id=2019-07-28
• Description: Extract wallpaper pictures from 2019-07-28
• Example: https://api.yimian.xyz/img?type=wallpaper&id=2019-07-28

Two-dimensional avatar

• GET/POST /img?type=head&id=15
• Description: Extract the avatar with id 15
• Example: https://api.yimian.xyz/img?type=head&id=15

Miao meow sauce picture bed

• GET/POST /img?type=imgbed&id=529745e0
• Description: Extract the picture bed with id 529745e0
• Example: https://api.yimian.xyz/img?type=imgbed&id=529745e0

4.6 path

Use absolute path to directly extract pictures, priority is higher than type, highest efficiency.

• GET/POST /img?path=xx/xx.xx
• Path format: Type/Picture File Name
• Example of path format: imgbed/img_529745e0_900x900_8_null_normal.jpeg
• Description: Extract pictures in xx/xx.xx
• Example: https://api.yimian.xyz/img/?path=imgbed/img_529745e0_900x900_8_null_normal.jpeg

4.7 R18

Whether to display 18 prohibited pictures, the default is false.

• GET/POST /img?type=xx&R18=true
  • Description: Randomly extract pictures containing R18 content in xx category
  • Example: https://api.yimian.xyz/img/?type=koino&R18=true

5 Error format

5.1 Cannot find the specified type

If the specified type cannot be found, a moe type picture will be automatically returned.

5.2 Can’t find matching images

Return JSON

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{
  "err": "error message"
}

The maximum number of global calls for each device is 500 per day!!

The Internet of Things system based on NodeJS, combined with D1 MINI microcontroller, helps you quickly realize the Internet of Things~

Quick Start

Current Support devices

• D1 MINI

Node.js Install Node.js

Node.js is a widely used programming language for web developers. To make use of wIoT, you should first install Node.js to your computer.

For windows user, you can follow the instruction in this website

Install wIoT package

After install Node.js and configure npm successfully, you should then use npm to download wIoT package by enter following command in your command window.

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npm install wiot

Windows user can use cmd or powershell.It should be notice that this may report error for some users. The solution is to open your cmd window as administrator. You can right click on cmd and choose run as an administrator. You can also press windows+R and input cmd then press Ctrl+Shift+Enter to open it as administrator.

Burn firmware

Connect your device to D1 MINI

• After burning the firmware, you should try to connect your device to D1 MINI
  Follow the steps below, I’m sure it would not be a problem for such a smart person like you

1. Reset your D1 MINI

• Find pin D0 on your D1 MINI, it should be in the middle of A0 and D5.
• Use a wire to connect 3V3 to D0. If your MINI works normally, you would see its BUILT-IN LED blink.
• You don’t have to wait until it stops blink, just stay for 2s, then you can pull out the wire and your MINI would reset.

2.Find your D1 MINI on your device

• After you finish step 1, your MINI would work in AP mode, which means you can search it with your smart phone or personal computer by scanning the Wi-Fi around
• If your MINI was reset successfully, you would find a Wi-Fi with SSID in the form of wiot-xx:xx:xx:xx:xx:xx.
  Example:
  
  “xx:xx:xx:xx:xx:xx” is the MAC address of this MINI, please try to remember the address for you may use it later

The default password for D1 MINI is 1234567890, enter the password and you should be able to connect to your MINI.

Connect D1 MINI to your Wi-Fi

Congratulations, you have successfully connect your device to D1 MINI
However, this is not the end, you should now try to connect D1 MINI to your Wi-Fi
Use the device which had just been connected to D1 MINI and follow the steps below

1. Visit the control page of D1 MINI

Visit http://192.168.0.1 with the browser on your device
Normally, you would see a webpage like this:

In this page, you can see the MAC Address and wIoT version of your MINI
Again, please remember the MAC Address

2.Submit SSID and password to your MINI

From the page, you can see two blanks that ask the SSID and password of your Wi-Fi
Input information of the Wi-FI which you would like to connect your MINI, click Submit
If you have input the right SSID and password, you will see a page showing the message: Set Successfully!! Rebooting!!
Then, after a minute, you will see the SSID of D1 MINI has vanished

If you submitted the wrong message, do not try to directly reconnect to D1 MINI. Restart the whole procedure from the reset part of the last section

Execute Example Code

If you have successfully connect D1 MINI to your Wi-Fi, you can execute the example code below to realize a simple function of wIoT
Before executing the code, you should first connect a LED to D1 MINI with positive pole connect to pin D4 and negative pole connect to GND

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var wiot = require('wiot'); //Import wiot package from npm

// Create an object of single chip
// Here are two parameters, MAC is the MAC adress of single chip, the output port should be defined in pin
// The MAC address should be editted by user
var MyMCU = new wiot.client({MAC: "3C:71:BF:3A:F6:CF", pin: {D4 : 1}, hint : true});


// The following code can let the BUILTIN_LED turn on for one second and off for one second periodically

// Wait for all the chips to get ready
wiot.begin([MyMCU], ()=>{ 
    // First parameter is the name of chip, second parameter is the function that is going to be executed

    // Set timer, pin 3 of MyMCU will pull up every 2 seconds
    setInterval(()=>{
        MyMCU.write(wiot.D4, wiot.HIGH);
    }, 2000);

    // Set timer, executer the command in {} after a one-second delay
    setTimeout(()=>{

    // Set timer, pin 3 of MyMCU will pull down every 2 seconds
        setInterval(()=>{
            MyMCU.write(wiot.D4, wiot.LOW);
        }, 2000);
    }, 1000);
});

The LED is expected to blink after you execute the code

Advanced development

Parameters

Parameters Declaration Example

General Example

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var MyMCU = new wiot.client({
    MAC: "xx:xx:xx:xx:xx:xx",
    pin: {
        D1: 0,
        D2: 0,
        D3: 1,
        D4: 1,
        D5: 0,
        D6: 1,
        D7: 0,
        D8: 0
    },
    hint: true,
    debug: false,
    ip: "192.168.0.55",
    port: 6666,
    ip_range: "192.168.0",
    localIP: "127.0.0.1",
    errDelayTime: 2000,
    okDelayTime: 30,
    resetDelayTime: 4500,
    noTryMaxTime: 15000,
    IntervalTime: 2000,
    MaxToReScanTime: 180000,
    MinResearchTime: 5000,
    IpScanTimeOut: 1,
    pingTimeout: 2,
    MaxTraceBackTimes: 8
});

Event Binding

Client

.on(event, handler)

Event List of client

• begin It begins when MCU starts to interact normally
• disConnected Disconnect from MCU
• reConnected Connection with MCU restored

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js
var MCU = new wiot.client({"MAC": "xx:xx:xx:xx:xx:xx"});

MCU.on('disConnected', function () {

    // Execute the command below when lost connection with MCU
    console.log('Disconnected with MCU!!');
});

Pin

.pinOn(pin, event, handler)

Event List of pin

• on Change output of pin from LOW to HIGH
• off Change output of pin from HIGH to LOW
• change Change the output of pin

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var MCU = new wiot.client({"MAC": "xx:xx:xx:xx:xx:xx"});

MCU.pinOn(wiot.D2, 'on', function () {
    // Execute when the output of D2 changes from LOW to HIGH
    console.log('D2 from LOW to HIGH!!');
});

API

• wiot.begin(): Execute when MCU is ready

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MCU0 = new wiot.client({MAC: "xx:xx:xx:xx:xx:xx", pin: {D4: wiot.OUTPUT}});
MCU1 = new wiot.client({MAC: "xx:xx:xx:xx:xx:ww"});

wiot.begin([MCU0, MCU1], ()=>{

    //Write the command you want to execute here
    //These command would execute once MCU0 and MCU1 are ready
});

+
wiot.loop(): A loop command，Suitable for conditional control statements

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MCU0 = new wiot.client({MAC: "xx:xx:xx:xx:xx:xx", pin: {D4: wiot.OUTPUT}});
MCU1 = new wiot.client({MAC: "xx:xx:xx:xx:xx:ww"});


// Following code would realize: When pin D5 of MCU0 receive HIGH，D4 of MCU1 would output HIGH
// When pin D5 of MCU0 receive LOW，D4 of MCU1 would output LOW

// This function receives two parameters: first is an array of objects for MCU, second is a function which use MCU array of objects as its parameter

wiot.loop([MCU0, MCU1], () => {
    if(MCU1.read(wiot.D5) == wiot.HIGH){
        MCU0.write(wiot.D4, wiot.HIGH);
    }else{
        MCU0.write(wiot.D4, wiot.LOW);
    }
});

Register

• wiot.register.set(status1, status2, function): Add a rule to register that status can be either value or function,
  function would trigger if status1 == status2
  The registry is designed to facilitate the use of various extension modules, See [extension module] below (# Sensor Extension Module).

• wiot.register.set(status, function): You can also pass in two functions, where the return value of status is of type bool, it would trigger the function if it changes to true

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var myLED = wiot.led(MyMCU, wiot.D4);
var pir = wiot.pir(MyMCU, wiot.D2);

//Sign up for a rule that says myLED lights up when pir detects a person
wiot.register.set(pir.getStatus, wiot.HIGH, ()=>{
    myLED.set(wiot.HIGH);
});

//Sign up for a rule that when people leave, myLED goes off
wiot.register.set(()=>{
    return (wiot.LOW == pir.getStatus);
}, ()=>{
    myLED.clear();
});

Sensor extension module

LED

• wiot.led(MCU, pin): Declare a LED module

• wiot.led.getStatus(): Get status of LED

• wiot.led.set(status, time = 0, isSmooth = false): Set led state, initial state, intermediate state, final state, period

• wiot.led.breath(period): Set a breathing LED

• wiot.led.clear(): Reset LED

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var wiot = require('wiot'); //Import wiot package from npm
MCU0 = new wiot.client({MAC: "3C:71:BF:3A:F6:CF", pin: {D4: wiot.OUTPUT}});

var myLED = wiot.led(MCU0, wiot.D4); //Create a new led object using the D4 port on MCU0

/* If myLED is not shining, light it up*/
if(!myLED.getStatus()){
    myLED.set(wiot.HIGH);
}

/* Set a breathing light with cycle of 2s */
myLED.breath(2000);

/* Set a LED which light 3 seconds and off 4 seconds */
myLED.set([wiot.HIGH, wiot.LOW], [3000, 4000]);

/* Set a breathing light which use 1 second to light and 3 second to extinguish */
myLED.set([wiot.LOW, wiot.HIGH], [1000, 3000], true);

/* Set a LED which shine with half brightness for 2 seconds, shine with full brightness for 3 seconds and then dextinguish for 2 seconds  */
myLED.set([100, wiot.HIGH, wiot.LOW], [2000, 3000, 2000]);

/* Turn off LED */
myLED.clear();

PIR (Passive Infrared Sensor)

• wiot.pir(MCU, pin): Declare a PIR module
• wiot.pir.getStatus(): Gets the PIR state, returns the value wiot.high (have people), wiot.low (no people)

Event Trigger

• wiot.pir.on(event, handler)

Events List

• detected Person detected
• undetected People out of the detective field
• change State change, includes from detected to undetected and from undetected to detected

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var wiot = require('wiot'); //Import wiot package from npm

MCU0 = new wiot.client({MAC: "3C:71:BF:3A:F6:CF"});

var myPIR = wiot.pir(MCU0, wiot.D2); //Create an object of pir, use the D2 port on MCU0

/* Output the status of pir to console */
console.log(myPIR.getStatus());

/* When human is detected，print "Detected People!" to console */
myPIR.on("detected", ()=>{
    console.log("Detected People!");
});

/* When human is out of the detection zone，print "No People!!" to console */
myPIR.on("undetected", ()=>{
    console.log("No People!!");
});

/* When there is a change to status, execute your command */
myPIR.on("change", ()=>{
    /* Write command in here */
});

IR Infrared Sensor

• wiot.ir(MCU, pin): Declare an IR module, pin can be analog or digital port
• wiot.ir.getStatus(): Get IR state, return value wiot.high (with a barrier), wiot.low (with no barrier), or a value of 0-1024 (only for analog port)

Event Trigger

• wiot.ir.on(event, handler)

Event List

• detected Barrier detected
• undetected Barrier vanished
• change Change state

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MCU0 = new wiot.client({MAC: "xx:xx:xx:xx:xx:xx"});

var myIR = wiot.ir(MCU0, wiot.D2); //Create a new ir object using the D2 port on MCU0

/* Output ir status to console */
console.log(myIR.getStatus());

/* When an object is detected, print "Detected Object!" to the console */
myIR.on("detected", ()=>{
    console.log("Detected Object!");
});

/* When the object move out of the detective area, print "No Object!!" to the console */
myIR.on("undetected", ()=>{
    console.log("No Object!!");
});

/* Execute the command when state changes */
myIR.on("change", ()=>{
    /* Your command */
});

lightSensor

• wiot.lightSensor(MCU, pin): Declare a lightSensor module, pin can be analog or digital port
• wiot.lightSensor.getStatus(): Get lightSensor state, return value wiot.HIGH(light), wiot.LOW(dark), or a value of 0-1024 (limited to analog port)

Event Trigger

• wiot.light.on(event, handler)

Event List

• light From dark to light
• dark From light to dark
• change Change state

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MCU0 = new wiot.client({MAC: "xx:xx:xx:xx:xx:xx"});
var myLightSensor = wiot.lightSensor(MCU0, wiot.D1); //Create a new pir object using the D2 port on MCU0

/* Output the LightSensor state to the console */
console.log(mylightSensor.getStatus());

/* When going from dark to Light, print "Light!!!" to the console */
myLightSensor.on("light", ()=>{
    console.log("Light!");
});

/* When going from light to Dark, print "Dark!!" to the console */
myLightSensor.on("dark", ()=>{
    console.log("Dark!!");
});

/* When the state changes, execute the command */
myLightSensor.on("change", ()=>{
    /* Your command */
});

Internet Extension Module

Mail module

Use this module to send messages to the specified mailbox. Proudly built with reference to Yimian API!

• wiot.mail(to, from = "wIoT"): Declare an mail module with sender’s name and reveiver’s address
• wiot.mail.send(subject, body): Send email with a subject and content

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var mail = wiot.mail("i@iotcat.me", "wIoT Test");

mail.send("Test", "Test from wiot!!");

guguji

Use this module to send messages to the specified cooing machine.Goo goo is a portable private printer, see official website.
To use this module, you need to apply for your own developer ak in advance on the official website. See here. Proudly reference Yimian API!

• wiot.guguji(ak, userID, memobirdID): Declare a goo goo chicken module, parameter: developer’s ak, user id, cooing machine id
• wiot.guguji.send(msg): Send message, need to pass in the message to be sent

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var gugu = wiot.guguji("9e55121803474371bfa25d20e554b31f", "832598", "b3ee06a8bd9b49e1");

gugu.print("This is from wIoT!!");

The solution to the Sino-US trade war is not in the United States, but in ourselves.

Regarding negotiations, there are relatively large disputes within the party, but in the end it is very likely that they will refuse to make concessions.
When U.S. tariffs rise, related domestic industrial chains will be transferred to Taiwan and Southeast Asian countries in large numbers, which will cause employment problems for 100 million people. Unlike previous crises, this time we not only have to guard against the intensification of the housing market bubble, but also there is not so much infrastructure that can provide employment. On the other hand, in recent years, China’s overcapacity problem has been solved mainly through exports, and the trade surplus is used to develop the domestic economy in order to achieve incredible economic growth. Now that the Trump administration imposes tariffs, this strategy will no longer work.

If it compromises in the negotiation, China will lose the opportunity of the Fourth Industrial Revolution that it finally took over, and its economy will be at the mercy of Japan and South Korea.

I think that under the premise of no compromise, there are three ways to break the game.

1. Wu Tong Taiwan
   This depends on whether Taiwan’s general election next year can find a legitimate reason for military reunification. But it does help alleviate domestic social focus issues.
2. Housing market reform
   It is very possible to turn the bubble crisis into capital for job creation.
3. Games
   Transfer the surplus labor force in the society into the game industry to ease the formation of social conflicts.

In order to alleviate the intensity of the unemployment shock, the central bank will increase imports and exports by printing the renminbi to depreciate the renminbi, attracting other countries to supplement the vacancy of the withdrawal of US capital.

the above. .

Reorganized my previous mail module and encapsulated an API by the way. Welcome everyone to call~

Method

Parameters (accept GET and POST)

• to recipient email address
• subject mail subject
• body email content (html format is recommended)
• from sender name

Request address

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https://api.yimian.xyz/mail

Example

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https://api.yimian.xyz/mail/?to=receiving mailbox&subject=mail subject&body=mail content&from=sender name

[scode type=”yellow”] If you encounter an error in GET delivery of the mail content, please try using POST[/scode]

Return value (json format)

• Parameter state::true (success) or false (failure)

[scode type=”dangerous”] There are 50 requests per day per IP[/scode]

Teach you how to fall in love with JS step by step.. ╮(╯▽╰)╭

Okay, just some summary

Those cute points in JS

• In the <script> tag, reasonably use defer="defer" (delayed execution) and async="async" (asynchronous execution)
• External JS can use other extensions (such as .php), but must return the correct MINE type
• Use var obj = preferredObj || backupObj; to provide a backup value ::aru:surprised::
• Use arguements[] to get parameters in the function
• No function signature, goodbye overload ::aru:meditation::
• The function has no reference to pass parameters, as long as the global variable is not used for deadly, the encapsulation is perfect
• Magic garbage collection function, no need to consider manually releasing memory during development
• Use function hh({}) to pass parameters directly to functions, which is more flexible
• Each position of the array can store different types of data ::aru:blood2::
• Array supports simulated stack operations, such as push() and pop()
• Array supports simulated queue operations, such as push() and shift()
• Array supports simulating queues from the opposite direction, such as unshift() and pop()
• sort() can customize the comparison function as a parameter
• The array splice() is so easy to use, right?
• Functions are objects and function names are pointers
• You can pass a function to another function as parameters, or you can return a function as the result of another function
• In the function, the current function name pointer can be obtained through arguments.callee
• Use arguments.callee.caller to get a reference to call the current function
• Use function.apply(this/*scope*/, arguments) or function.call(this, arg1, arg2...) to specify the scope to run the function
• Use the function intrinsic property function.length to get the number of expected parameters
• Inherit the property toLocaleString(), toString(), and valueOf() return code through the function to facilitate debugging
• Use indexOf() and lastIndexOf() to find the element’s appearance
• trim() delete spaces at the beginning and end of the string
• Support regular RegExp
• The magical but terrible eval("") can translate the string into code and execute it in place
• encodeURI()/decodeURI() and encodeURIComponent()/decodeURICompoent() handle uri
• Call the function immediately function()()();
• Built-in Math object
• ceil(), floor(), round() in Math up, down, standard rounding
• Math.random() is a random number greater than zero and less than one
• Use functionName: function(){} in the object to directly define the function
• In ES6 (x)=>x+1 is equivalent to function(x){return x+1;}
• Use ;(function(name, context, definition){moudle.exports = definition();})('funationName', this, function()()); to encapsulate the module

Be careful

• It is not recommended to use with statement
• Less use of label
• 0.1 + 0.2 != 0.3 floating point tiankeng, similar to C
• ~26 == -27 Use bitwise not to improve efficiency
• Identifier query is carried out from the internal environment to the external environment
• No block-level scope, different from C++
• var obj2 = obj1; is actually a reference
• The object is passed when the function is passed, but the pointer is actually passed
• Set global variables to null when used up to improve performance
• Use variable attributes to access objects can only use obj[var]
• var sum = function sum(){}; will report an error in Safari
• You cannot add attributes and methods to basic type values
• new Number("25") returns the object, and Number("25") returns 25
• All objects in Boolean expressions are true

I’ve been playing on the web intermittently for a year, and some of the TrustAsia certificates from Tencent’s Yunshang have started to expire one after another. It’s very fragrant.. So I started to try to apply for Let’s Encrypt’s free certificate, and realized automatic renewal|´・ω・)ノ

Prerequisites

• Must be Centos7 system, others have not been tested and are not guaranteed to be valid
• Have your own domain name
• Confirm that dns has pointed the domain name to the server
• The firewall allows port 80 and 443
• The nginx proxy has been configured, and domain name can be accessed via http (be sure to be able to access)

Install certbot

Install certbot via yum

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$ yum update #Update yum source
$ yum install -y epel-release #Install epel source
$ yum install -y certbot #Install certbot

Initial application certificate

Apply for a domain name certificate for the first time

The format is

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$ certbot certonly --webroot -w [Web site directory] -d [domain name] -m [contact email address] --agree-tos

E.g

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$ certbot certonly --webroot -w /opt/www/demo.yourdomain.com -d demo.yourdomain.com -m yourname@gmail.com --agree-tos