Alibaba cloud development board haas510 responds to UART serial port instructions

Abstract ： When developing IOT devices , Commonly used MCU+ Hardware structure of IOT module ,HaaS510 It is a very good IOT module . This article shares with you HaaS510 On the basis of success in the cloud , How to respond to UART Serial port instruction .

The experiment purpose ： adopt haas510 Receive the serial port instructions from the upper computer , adopt DEBUG Serial port display .

Hardware ：haas510 (2.0 edition ）,USB A serial port

Software ：win7 x64,vscode

Catalog

 1.HaaS510 There are several serial ports on the board ？

 2. Principle of receiving and sending serial port instructions

 3.amp Light application on the use of serial port

 4. Write serial port response code

  5. Observe the operation effect

---

1.HaaS510 There are several serial ports on the board ？

The serial port on the development board has 2 individual , They are user serial ports MAIN UART And debug serial port DEBUG UART.

HaaS510 Is based on EC600S Developed , Its external serial port is EC600S Serial port .EC600S The module leads out the stamp hole , There are also pads at the bottom . As shown in the red box below ,EC600S In the pins of the module , It provides 2 A serial port , One of them is debugging , The other is that users use .

  because EC600S The necessary circuits have been encapsulated in a solid metal shell , So if you use these two serial ports , It is only necessary to lead the wire to the corresponding terminal . The terminal blocks used in the Alibaba cloud development board are XH2.54.

 2. Principle of receiving and sending serial port instructions

The author drew a diagram , Used to explain the basic process of serial communication . In different MCU When programming , The code is different , But the core content is the same , Is to receive in turn , There is a buffer when receiving , When the buffer is full, there will be an interrupt , After the interrupt, you should respond , There may also be data verification and other contents . It often takes dozens of lines of code to receive and process a string .

The purpose of this experiment is to realize HaaS510 Receive the instructions from the upper computer , After receiving the command , We can parse these instructions , Or upload it to the Internet of things platform as data . In order to observe whether the data is received correctly , We adopt the method of receiving and then sending it through the serial port . If the same is sent and received , Then it proves that the experiment is successful .

 3.amp Light application on the use of serial port

Use “ Low code ” Of course, we don't want to use too many statements to deal with an old serial port .

HaaS The team has helped us do well .

Just use JavaScript.

official API Help document connection is

uart - A serial port https://help.aliyun.com/document_detail/268752.htmlhttps://help.aliyun.com/document_detail/268752.html

because JavaScript The language uses an event driven mechanism to respond to user actions , Alibaba cloud has helped us to UART Time and bottom driver debugging are done .

therefore , We can pass a very simple JavaScript sentence , Respond to the upper computer or other MCU Serial port command event sent , The complex serial communication process can be realized .

stay HaaS in , The name of this event is “data”. Name is what it is , What is passed on the serial port is indeed “data”.

The reference operation for programming this event is ：

 4. Write serial port response code

The purpose of this experiment is to haas510 Receive the serial port instructions from the upper computer , adopt DEBUG Serial port display .

We're in a HaaS510 Debug on the basis of the routine that successfully goes to the cloud and reports attributes . This facilitates the next step of uploading the data received by the serial port to the cloud .

The code is as follows ：

var iot = require('iot');
var network = require('network');
var uart = require('uart');
var net = network.openNetWorkClient();
/*  For information about device triples, please refer to common In the catalog iot Component description  */
var productKey = 'gcXXXXXvu2';
var deviceName = 'cewSSSSS001';
var deviceSecret = 'ee213aSSSSSSSSSadcdedb3a9';
//  Build Internet of things connection instances 
var device;
var lightSwitch = 0;


  //  Open the user serial port , stay HaaS in , The serial port number of the user is UART2
  var serial = uart.open({
    id: 'UART2'
  });

  var msgbuf = [97, 98, 99, 100];

  function ArrayToString(fileData) {
    var dataString = "";
    for (var i = 0; i < fileData.length; i++) {
      dataString += String.fromCharCode(fileData[i]);
    }
    return dataString;
  }

//net.on It is used to connect the IOT platform with triple data , The core is to implement a MQTT client 
net.on('connect', function () {
    device = iot.device({
        productKey: productKey,
        deviceName: deviceName,
        deviceSecret: deviceSecret,
        region: 'cn-shanghai',
        success: function () {
            console.log('iot: [success] connect');
        },
        fail: function () {
            console.log('iot: [failed] connect');
        }
    });
})
// Timing procedure , This program implements 5 Second timing , Turn the status of the main light switch every time , Send an array of data to the user serial port 
// Then send the main light switch status to the Internet of things platform 
setInterval(function () {
    lightSwitch = 1 - lightSwitch;

    // user uart send data
    serial.write(msgbuf);
    

/*  Error model    iot.postProps({
                       payload: {LightSwitch:'0'}
                    })*/
/* Correct demonstration , To send attributes , You have to use stringify Talent */
    device.postProps(
        JSON.stringify({
            LightSwitch: lightSwitch
        })
    );
  
  }, 5000);


// serial.on Used to respond to serial port data receiving events , What does the user receive through the serial port , Just send something through the debugging serial port .
// Be careful , The two serial ports are not the same .
serial.on('data', function(data) {
  console.log('uart receive data is ' + ArrayToString(data));
});

5. Observe the operation effect

The effect we want to achieve is based on cloud online on the device , Receive the upper computer or MCU Serial port instructions sent .

First connect the hardware to the computer , Here we use 2 A serial port .

Then burn the program , Please refer to the article for the method of burning

Alibaba cloud development board vscode Development environment construction https://blog.csdn.net/youngwah292/article/details/120356887?spm=1001.2014.3001.5501https://blog.csdn.net/youngwah292/article/details/120356887?spm=1001.2014.3001.5501

Open the Internet of things platform , Check whether the device is online

  Then observe whether the interval 5 Second report attribute , It is found that attributes can be reported normally .

  Next open 2 A serial port assistant , Corresponding to user serial port and debugging serial port respectively . It was found by experiment that , Achieved the desired effect . The information received is complete 、 accuracy .

  The core code actually has only one sentence , In a word , Can be realized HaaS510 Keep an eye on the data on the user's serial port , Once there's data , Just send it out .

serial.on('data', function(data) {
  console.log('uart receive data is ' + ArrayToString(data));  

});

  In engineering application , It is very common to use the serial port to connect the IOT module . The company's original hardware engineers can focus on the research and development of hardware functions , When the device is on the cloud , Just connect an Internet of things module , What data needs to be sent on the cloud , Send instructions directly through the serial port .

The Internet of things device with this structure has a disadvantage , The structure is loose , The reliability is not particularly high . For example AT IOT module in the form of instructions , It requires multiple steps to operate before it can be put into the cloud , If you want to report attributes , Complex string operation is required to obtain the effect required by cloud settings .

It's about using HaaS510 Can make up for this shortcoming .HaaS510 Only a few statements are needed to implement the cloud on the device .

Today we learned to use 1 A statement can realize the receiving of serial port instructions ,HaaS The simplicity of .

next step , We will directly submit the data obtained through the serial port to the cloud platform .