MQTT Downlink issue

#1

application/3101de9f-6ad1-4bdc-babc-e339439ce135/device/e66230c79f0c7d2a/command/down

image
image1560×830 44.4 KB

image
image1541×690 22 KB

the downlink doesnt recieve by device, but on portal

image
image1452×707 15.6 KB

recieves well,

what should be mistake?

#2

I’m not 100% sure what you mean with this. By showing a screenshot of an empty queue, you mean it was sent by ChirpStack but not received by the device?

#3

Thanks for rapid reach,

i want to downlink in 2 ways with MQTT,

Unicast ( single device)
and Multicast

need to make MQTT with C# application

here is my code sample but somethings wrong, can you assist me to fix it?

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

public class Program
{
    public static async Task Main(string[] args)
    {
        // MQTT client oluştur
        var factory = new MqttFactory();
        var mqttClient = factory.CreateMqttClient();

        // MQTT client ayarları
        var options = new MqttClientOptionsBuilder()
            .WithClientId("YourClientId")
            .WithTcpServer("YourMqttBrokerAddress", 1883) // Port numarası genellikle 1883'tür
            .WithCredentials("YourUsername", "YourPassword")
            .WithCleanSession()
            .Build();

        // MQTT client'ı bağla
        await mqttClient.ConnectAsync(options);

        // Downlink mesajını oluştur
        var downlinkMessage = new
        {
            confirmed = true, // Onaylanmış downlink mesajı mı?
            fPort = 1, // FPort değeri
            data = "SGVsbG8gd29ybGQ=" // Base64 formatında veri ("Hello world" örneği)
        };

        // Downlink mesajını JSON'a çevir
        var downlinkMessageJson = JsonConvert.SerializeObject(downlinkMessage);

        // Downlink mesajını MQTT mesajına çevir
        var message = new MqttApplicationMessageBuilder()
            .WithTopic("application/{APPLICATION_ID}/device/{DEV_EUI}/command/down") // Uygulama ID'si ve cihaz EUI'si ile konuyu değiştirin
            .WithPayload(downlinkMessageJson)
            .WithExactlyOnceQoS()
            .WithRetainFlag()
            .Build();

        // Downlink mesajını gönder
        await mqttClient.PublishAsync(message);
    }
}```

Thanks
#5

That’s totally true, i send from also hex data, its totally works fine but with mqtt application, it not got recieve from device, maybe i am missing some querry or url?

#6

i didnt use deveui at payload json, problem may acquire becaause of that?