[라즈베리 파이] MQTT 연결 방법

sudo apt-get update

sudo apt-get install mosquitto mosquitto-clients

sudo systemctl start mosquitto
sudo systemctl enable mosquitto

sudo systemctl restart mosquitto

mosquitto_sub -t home/temperature

using System;
using System.Text;
using System.Threading.Tasks;
using MQTTnet;
using MQTTnet.Client;

var factory = new MqttFactory();
var mqttClient = factory.CreateMqttClient();

var options = new MqttClientOptionsBuilder()
    .WithClientId("RaspberryPiClient")
    .WithTcpServer("Raspberry Pi IP", 1883) // Replace with your Raspberry Pi IP
    .Build();

mqttClient.ConnectedAsync += async e =>
{
    Console.WriteLine("Connected to MQTT Broker.");

    // 주제 구독 설정
    await mqttClient.SubscribeAsync(new MqttClientSubscribeOptionsBuilder()
        .WithTopicFilter("home/temperature")
        .WithTopicFilter("home/humidity")
        .Build());

    Console.WriteLine("Subscribed to topics: home/temperature, home/humidity");
};

mqttClient.DisconnectedAsync += e =>
{
    Console.WriteLine("Disconnected from MQTT Broker.");
    return Task.CompletedTask;
};

mqttClient.ApplicationMessageReceivedAsync += e =>
{
    var topic = e.ApplicationMessage.Topic;
    var message = Encoding.UTF8.GetString(e.ApplicationMessage.Payload);
    Console.WriteLine($"Received message from {topic}: {message}");
    return Task.CompletedTask;
};

await mqttClient.ConnectAsync(options);
Console.WriteLine("Press any key to exit...");
Console.ReadLine();
await mqttClient.DisconnectAsync();

using System;
using System.Text;
using System.Threading.Tasks;
using MQTTnet;
using MQTTnet.Client;

namespace RaspberryPiMQTTClient
{
    class Program
    {
        static async Task Main (string[] args)
        {
            var factory = new MqttFactory();
            var mqttClient = factory.CreateMqttClient();

            var options = new MqttClientOptionsBuilder()
                .WithClientId("RaspberryPiClient")
                .WithTcpServer("Raspberry Pi IP", 1883) // Replace with your Raspberry Pi IP
                .Build();

            // Event handler for successful connection
            mqttClient.ConnectedAsync += async e =>
            {
                Console.WriteLine("Connected to MQTT Broker.");

                // Subscribe to the topics
                await mqttClient.SubscribeAsync(new MqttClientSubscribeOptionsBuilder()
                    .WithTopicFilter("home/temperature")
                    .WithTopicFilter("home/humidity")
                    .Build());

                Console.WriteLine("Subscribed to topics: home/temperature, home/humidity");
            };

            // Event handler for when the client disconnects
            mqttClient.DisconnectedAsync += e =>
            {
                Console.WriteLine("Disconnected from MQTT Broker.");
                return Task.CompletedTask;
            };

            // Event handler for received messages
            mqttClient.ApplicationMessageReceivedAsync += e =>
            {
                var topic = e.ApplicationMessage.Topic;
                var message = Encoding.UTF8.GetString(e.ApplicationMessage.Payload);
                Console.WriteLine($"Received message from {topic}: {message}");
                return Task.CompletedTask;
            };

            // Connect to the MQTT broker
            await mqttClient.ConnectAsync(options);

            Console.WriteLine("Press any key to exit...");
            Console.ReadLine();

            // Disconnect from the MQTT broker
            await mqttClient.DisconnectAsync();
        }
    }
}