arduino mqtt - 如何创建多设备序列？ MQTT 客户端重命名

Question

I am trying to create a small project on arduino (WeMos D1 mini). It is to be based on the communication of several devices with a computer using the MQTT protocol.

The protocol itself works great on arduino. I wrote a program that works as expected, at least at this stage of the project.

The problem is that it works fine on a single arduino. I need to create a network of devices.

Is it possible to execute the sequence on several devices communicating via MQTT?

Example: Own MQTT Broker on Raspberry Pi. Three Arduino (id: 001; 002; 003) with the same program. Is the sequence possible: I am sending a startup message from the computer to Arduino 001. The device does some work, then sends a log to the computer and a message to Arduino 002. Device 002 does the job, then sends a log to the computer and a message to Arduino 003. Device 003 does the job, then sends the log to the computer and completes the sequence.

Message from computer to Arduino 001 is sent to Topic device / 001, to Arduino 002 it is sent to Topic device / 002 and similarly to Arduino 003 it is sent to Topic device / 003.

Today I have a problem because when I run all Arduino's at the same time, only one is active on the network. the other two are unresponsive although the Broker receives the information. Why?

So, after lond descriptions time for code:

#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <PubSubClientTools.h>
#include <Thread.h> 
#include <ThreadController.h>

#define WIFI_SSID           "MyNetwork"
#define WIFI_PASS           "123456789"
#define serial              9600
#define MQTT_SERVER         "192.168.8.107"
#define MQTT_PORT           1883

#define id_dev              "001"


WiFiClient espClient;
PubSubClient client(MQTT_SERVER, MQTT_PORT, espClient);
PubSubClientTools mqtt(client);

ThreadController threadControl = ThreadController();
Thread thread = Thread();

int value = 0;
const String s = "";
String service                  = "service"; 
String main_name                = "test"; 
String sub_main_name            = "test";
String info_name                = "test"; 
String sub_info_name            = "test";

void setup() {
  Serial.begin(serial);
  Serial.println("-| WiFi Connection |--------------------------------");
  setup_wifi();
  Serial.println("-| MQTT Connection |--------------------------------");

  Serial.print(s+"Connecting to MQTT: "+MQTT_SERVER+" ... ");
  if (client.connect("ESP8266Client")) {
    Serial.println("connected");

    mqtt.subscribe(service+"/"+id_dev,          topic_service); 
    mqtt.subscribe(main_name,                   topic_main_name);
    mqtt.subscribe(info_name,                   topic_info_name);
  } else {
    Serial.println(s+"failed, rc="+client.state());
  }

  // Enable Thread
  // thread.onRun(publisher);
  thread.setInterval(2000);
  threadControl.add(&thread);

  Serial.println("----------------------------------------------------");
  Serial.println();
}

void loop() {
  client.loop();
  threadControl.run();
}

void setup_wifi() {
  Serial.print("Connecting to ");
  Serial.println(WIFI_SSID);
  WiFi.begin(WIFI_SSID, WIFI_PASS);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void publisher() {
  ++value;
  mqtt.publish("test/001", s+"Hello World! - No. "+value);
}

void topic_service(String topic, String message) {
  Serial.println(s+"Message arrived in function 1 ["+topic+"] "+message);
  sub_main_name = message;
  subscription(sub_main_name);
}

void topic_main_name(String topic, String message) {
  Serial.println(s+"Message arrived in function 2 ["+topic+"] "+message);
  if (message == "111") {
    Serial.println("Is OK!");
    String message_sent = "111";
    mqtt.publish(sub_main_name+"/002", message_sent);
  } else {
    Serial.println("Something wrong!");
  }
}
void topic_info_name(String topic, String message) {
  Serial.println(s+"Message arrived in function 3 ["+topic+"] "+message);
  sub_info_name = message;
}

void subscription(String wiadomosc){
  if(main_name != wiadomosc){
    Serial.println("main_name: " + main_name + " | sub_main_name: " + sub_main_name +" <- for change");
    main_name = sub_main_name+"/"+id_dev;
    info_name = sub_main_name+"/"+id_dev+"/i";
    mqtt.subscribe(main_name, topic_main_name);
    mqtt.subscribe(info_name, topic_info_name);
  }
}

//----------------------------------------------------

The same code will be uploaded to all devices, diferent will be only ID (id_dev). This is a simple version of my program but it still not working well. On one device is ok but if I run two or more... only lastone is active. The rest are dosn't work (are not visible in network).

I need help getting a network of these devices up and running and communicating between them.

Answer 1

I checked on 2 devices logged in at the same time.

ID 001 (Serial Monitor Tool):

-| WiFi Connection |--------------------------------
Connecting to LinkHome
.......
WiFi connected
IP address: 192.168.8.132
Mac address: 84:F3:EB:0C:42:5E
-| MQTT Connection |--------------------------------
Connecting to MQTT: 192.168.8.107 ... connected
----------------------------------------------------

ID 002 (Serial Monitor Tool):

-| WiFi Connection |--------------------------------
Connecting to LinkHome
.......
WiFi connected
IP address: 192.168.8.123
Mac address: 84:F3:EB:0C:42:55
-| MQTT Connection |--------------------------------
Connecting to MQTT: 192.168.8.107 ... connected
----------------------------------------------------

(log from broker):

1660763173: New connection from 192.168.8.123:63287 on port 1883.
1660763173: New client connected from 192.168.8.123:63287 as ESP8266Client (p2, c1, k15).
1660763213: New connection from 192.168.8.132:51163 on port 1883.
1660763213: Client ESP8266Client already connected, closing old connection.
1660763213: New client connected from 192.168.8.132:51163 as ESP8266Client (p2, c1, k15).

There seems to be a problem in the log file. Two devices named ESP8266Client.

How can I change the device name?

Answer 2

I checked on 2 devices logged in at the same time.

ID 001 (Serial Monitor Tool):

-| WiFi Connection |--------------------------------
Connecting to LinkHome
.......
WiFi connected
IP address: 192.168.8.132
Mac address: 84:F3:EB:0C:42:5E
-| MQTT Connection |--------------------------------
Connecting to MQTT: 192.168.8.107 ... connected
----------------------------------------------------

ID 002 (Serial Monitor Tool):

-| WiFi Connection |--------------------------------
Connecting to LinkHome
.......
WiFi connected
IP address: 192.168.8.123
Mac address: 84:F3:EB:0C:42:55
-| MQTT Connection |--------------------------------
Connecting to MQTT: 192.168.8.107 ... connected
----------------------------------------------------

(log from broker):

1660763173: New connection from 192.168.8.123:63287 on port 1883.
1660763173: New client connected from 192.168.8.123:63287 as ESP8266Client (p2, c1, k15).
1660763213: New connection from 192.168.8.132:51163 on port 1883.
1660763213: Client ESP8266Client already connected, closing old connection.
1660763213: New client connected from 192.168.8.132:51163 as ESP8266Client (p2, c1, k15).

There seems to be a problem in the log file. Two devices named ESP8266Client.

How can I change the device name?

---

Ok, I found a solution. It was easier than I thought. By the way, I will also be able to change hostnames.

To change the hostname I added three lines:

#define id_dev              "002"
String newHostname = "client_"+String(id_dev); // for change the hostname
...
void setup_wifi() {
  WiFi.mode(WIFI_STA); // for change the hostname
  WiFi.hostname(newHostname); // for change the hostname
  
  Serial.print("Connecting to ");
  Serial.println(WIFI_SSID);
  WiFi.begin(WIFI_SSID, WIFI_PASS);
...

To change mosquitto client name: I change the name in line:

...
Serial.print(s+"Connecting to MQTT: "+MQTT_SERVER+" ... ");
  if (client.connect("dev_001")) {
    Serial.println("connected");
...

Thanks for the hint with the log file, I admit I didn't think about it.