Arduino Mega - mqtt 客户端仍在重新连接

Question

我想在家里进行 MQTT 通信。我有带 MQTT Broker (mosquitto) 的 RPI4，并试图通过 W5500 lite 以太网模块连接 Arduino mega。

MQTT 代理通过手机中的“MyMQTT”应用程序和 Openhab 应用程序进行测试 - 它的工作就像一个魅力。

我在循环后使用 PubSubClient 库中的 delay() 示例（我如何在此处的另一个主题中找到...）：

/*
Basic MQTT example
*/

#include \<SPI.h\>    
#include \<Ethernet3.h\>    
#include \<PubSubClient.h\>    

// Update these with values suitable for your network.
byte mac\[\] = {0x00, 0xAA, 0xBB, 0xCC, 0xDE, 0x02};
IPAddress ip(192, 168, 0, 101);
IPAddress gateway(192, 168, 0, 1);
IPAddress subnet(255, 255, 0, 0);

void callback(char\* topic, byte\* payload, unsigned int length) {
    Serial.print("Message arrived \[");
    Serial.print(topic);
    Serial.print("\] ");
    for (int i=0;i\<length;i++) {
        Serial.print((char)payload\[i\]);
    }
    Serial.println();
}

EthernetClient ethClient;
PubSubClient client(ethClient);

void reconnect() {
    // Loop until we're reconnected
    while (!client.connected()) {
        Serial.print("Attempting MQTT connection...");
        // Attempt to connect
        if (client.connect("arduinoClient9", "user", "pass")) {
            Serial.println("connected");
            // Once connected, publish an announcement...
            client.publish("outTopic","hello world");
            // ... and resubscribe
            client.subscribe("/hello");
            delay(100);
        } else {
            Serial.print("failed, rc=");
            Serial.print(client.state());
            Serial.println(" try again in 5 seconds");
            // Wait 5 seconds before retrying
           delay(200);
        }
    }
}

void setup() {
    Serial.begin(115200);

    client.setServer("192.168.0.99", 1883);
    client.setCallback(callback);

    Ethernet.begin(mac, ip);
    // Allow the hardware to sort itself out
    delay(1500);
}

void loop()
{
    if (!client.connected()) {
        reconnect();
    }
    client.loop();
    delay(100);
}

Arduino 仍在重新连接 - 我认为这是一个问题（mosquitto.log）：

arduino 重新连接时许多消息丢失：

看起来

client.connected()

经常是假的。但为什么？ :-(