arduino mqtt - How to create multi device sequence? MQTT client rename - arduino

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?
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.