As you have seen, all endpoints in MQTT connect to the broker in the same way as MQTT clients. The same is true for the controller, which subscribes to the information published by the sensor and publishes commands to the actuator, as shown in the following code:
Client = new MqttClient ("iot.eclipse.org", MqttClient.DefaultPort,"LearningIoTController", string.Empty, false);
Client.Open ();
Client.CONNECT (20, true);To handle events from the sensor, we need to register an event handler, as we did for the actuator; this time, we will register it as a lambda function for the sake of simplicity. This means we will provide the code to handle events before we could actually perform the subscription.
Client.OnDataPublished += (Sender, e) =>
{
string Topic = e.Topic;
if(!Topic.StartsWith ("Clayster/LearningIoT/Sensor/"))
return;
string s = System.Text.Encoding.UTF8.GetString(e.Data);
PhysicalMagnitude Magnitude;
...