制作不阻塞ESP8266/Arduino的UDP类 [英] Making a UDP class which doesn't block an ESP8266 / Arduino

问题描述

我需要在Arduino兼容项目中侦听ESP8266上的特定UDP端口并在收到适当消息时做出响应，同时在主程序循环中执行其他应用程序工作.

I have a need in my Arduino compatible project to listen on an ESP8266 to a specific UDP port and respond when an appropriate message is received, whilst doing other application stuff in the main program loop.

我想将UDP内容抽象到自己的类中，这就是我的问题所在.

I want to abstract the UDP stuff into its own class, and this is where my question comes.

如何让我的班级继续听，阅读一个UDP数据包，然后调用发送响应方法，而无需在主程序循环中放入大量代码?

How do I let my class continue to listen, read a UDP packet, and then call a send response method, without putting lots of code into the main program loop?

我的课程的接口是:

#ifndef Discover_Me_h
#define Discover_Me_h

#include "Arduino.h"

class DiscoverMe
{
  public:
    DiscoverMe(); //Constructor
    listenForPacket();// listens for packet, if one arrives it calls respond()
    respond();//Responds to the host which sent the packet with some data
};

#endif

主程序具有:

    #include "DiscoverMe.h"
include "Arduino.h"

DiscoverMe dm;

void setup() {
  // put your setup code here, to run once:
 pinMode(ledPin, OUTPUT);
  dm.listenForPacket();
}

void loop() {
  // I WANT MY DiscoverMe class to still work when my program gets here

  int switchVar = 1;
  digitalWrite(ledPin, switchVar);
    delay(200);
    if (switchVar == 1) {
      switchVar = 0;
    } else {
      switchVar = 1;
    }
}

如果我初始化并调用DiscoverMe对象，然后调用listenForPacket()，我有2个问题:

If I initalise and call my DiscoverMe object , and call listenForPacket() I have 2 questions:

1. 如何不阻塞UDP.begin()(将在listenForPacket()方法中使用)，以使程序到达其loop()?
2. 如果我的程序到达了它的循环，DiscoverMe侦听器将继续无限侦听，如果没有，我如何使它表现得如此?我想我想问的是，一旦loop()被击中，这些类的行为是否会被忽略，或者它们是否在单独的线程中运行?

1. How do I make the UDP.begin()(which will be in the listenForPacket() method) not block, allowing my program to reach its loop()?
2. If my program reaches it's loop, will the DiscoverMe listener continue to listen infinitely, if no, how do I make it behave as such? I guess I am asking, once loop() is hit, are the classes behaviours ignored, or do they run in separate threads?

推荐答案

答案与@maximilian相同:

The answer was as per @maximilian:

在循环中，您将必须每次检查是否有数据包到达.这就是UDP库的工作方式(if(Udp.parsePacket()> 0)).

In the loop, you will have to check if a packet has arrived every time. That's how the UDP library works (if(Udp.parsePacket() > 0)).

从设计角度来看，最好创建一个DiscoverMe :: HandlePacket函数，该函数将检查数据包是否可用，然后对其进行操作，并在每次循环迭代中调用它.在设置功能中，您只能将UDP客户端绑定到特定端口. Udp.begin()仍然不会阻止.

Design-wise, it would be best to make a DiscoverMe::HandlePacket function which will check if a packet is available, then act on it, and is called in every loop iteration. In the setup function, you may only bind your UDP client to a specific port. Udp.begin() will not block anyways.

这已实施，我可以确认它是否有效.

This was implemented and I can confirm it works.

长话短说，图书馆似乎需要一种称为的方法.在主程序循环中，使该类与基础接触，看看它是否需要做任何工作.

Long story short, libraries seem to require a method which will be called . during the main program loop, to touch base with the class and see if it needs to do any work.

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