This document describes how to try out device interconnection based on cross-device messaging and the rule engine in a smart home scenario with the aid of the IoT Hub device SDK for Android. For more information, please see Scenario 1: Device Interconnection.
To try out device interconnection, you need to create two types of smart devices (Door and AirConditioner) as instructed in the documentation. You also need to configure the rule engine as instructed in Overview and forward the data to another topic.
The Door model corresponds to the Door.java file in the SDK demo. You need to enter the corresponding parameters in app-config.json.
{
...
"DOOR_PRODUCT_ID": "",
"DOOR_DEVICE_NAME": "",
"DOOR_DEVICE_PSK": "",
...
}
The Airconditioner model corresponds to the Airconditioner.java file in the SDK demo. You need to enter the corresponding parameters in app-config.json.
{
...
"AIRCONDITIONER_PRODUCT_ID": "",
"AIRCONDITIONER_DEVICE_NAME": "",
"AIRCONDITIONER_DEVICE_PSK": ""
}
Note: the Door and Airconditioner in the demo connect to IoT Hub through device key. If you want to connect through certificate/device private key, you need to configure the following two fields in the Door.java and Airconditioner.java files:
DEVICE_KEY_NAME and DEVICE_CERT_NAME
When the MQTT authentication method is key authentication, you don't need to add the SSL configuration to MqttOptions; instead, you can use TCP. When you use SDK v3.3.0 or below, key authentication requires adding the SSL configuration options.setSocketFactory(AsymcSslUtils.getSocketFactory()); to MqttOptions.
When the MQTT authentication method is certificate authentication, you need to add the SSL configuration options.setSocketFactory(AsymcSslUtils.getSocketFactoryByAssetsFile(mContext, DEVICE_CERT_NAME, DEVICE_KEY_NAME)); to MqttOptions.
Run the demo, switch the tab at the bottom to select the device interconnection module, initialize Airconditioner, and connect it to MQTT through authenticated connection. After it is connected, subscribe to its own ${productId}/${deviceName}/control topic. Below is the sample code:
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
mDoor = new Door(IoTEntryFragment.this.getContext()); // Initialize the `Door` instance without authenticated connection to MQTT
mAir = new Airconditioner(this.getContext(), new AirMqttActionCallBack()); // Initialize the `Airconditioner` instance for authenticated connection to MQTT and set the MQTT callback
}
private class AirMqttActionCallBack extends TXMqttActionCallBack {
@Override
public void onConnectCompleted(Status status, boolean reconnect, Object userContext, String msg) { // Authenticated MQTT connection is completed
if (status.equals(Status.OK)) {
mAir.subScribeTopic(); // Subscribe to its own topic
}
}
...
@Override
public void onMessageReceived(String topic, MqttMessage message) { // Receive a message from the cloud
String logInfo;
if (message.toString().contains("come_home")) {
logInfo = "receive command: open airconditioner, count: " + atomicInteger.getAndIncrement();
} else {
logInfo = "receive command: close airconditioner, count: " + atomicInteger.getAndIncrement();
}
mParent.printLogInfo(TAG, logInfo, textView);
}
}
The following logcat log represents the process in which the Airconditioner device is connected successfully and subscribes to its own topic. In the console, you can see that the status of the Airconditioner device has been updated to online.
I/com.tencent.iot.hub.device.java.core.mqtt.TXMqttConnection: Starting subscribe topic: XMN6AZ4M0Y/airConditioner1/control
I/IoTEntryActivity: onSubscribeCompleted, status[OK], message[subscribe success]
In the device interconnection module, click Come Home, and it will trigger the authentication of the Door device for connection to MQTT. After the device is connected successfully, it will subscribe to its own ${productId}/${deviceName}/event topic. As the rule engine in the cloud is configured to forward the data, it will forward messages from the topic to the Airconditioner device. Below is the sample code:
public void enterRoom() {
...
mqttConnection = new TXMqttConnection(mContext, PRODUCT_ID, DEVICE_NAME, SECRET_KEY, new DoorMqttActionCallBack());
mqttConnection.connect(options, null);
...
if (mqttConnection.getConnectStatus().equals(TXMqttConstants.ConnectStatus.kConnected)) { // Directly publish to its own topic if it is connected
...
mqttConnection.publish(topic, message, null);
}
...
}
private class DoorMqttActionCallBack extends TXMqttActionCallBack {
@Override
public void onConnectCompleted(Status status, boolean reconnect, Object userContext, String msg) { // Authenticated MQTT connection is completed
if (status.equals(Status.OK)) { // Connected successfully
if (!reconnect) { // Publish to its own topic if it is not reconnected
MqttMessage message = new MqttMessage();
message.setPayload(COME_HOME_MESSAGE.getBytes());
String topic = String.format("%s/%s/%s", PRODUCT_ID, DEVICE_NAME, "event");
mqttConnection.publish(topic, message, null);
}
}
}
...
}
Observe the logcat log.
I/TXMQTT_1.2.3: Start connecting to ssl://9RW4A8OOFK.iotcloud.tencentdevices.com:8883
I/iot.scenarized.Door: onConnectCompleted:connected to ssl://9RW4A8OOFK.iotcloud.tencentdevices.com:8883
I/com.tencent.iot.hub.device.java.core.mqtt.TXMqttConnection: Starting publish topic: 9RW4A8OOFK/door1/event Message: {"action": "come_home", "targetDevice": "airConditioner1"}
I/TXMQTT_1.2.3: Received topic: XMN6AZ4M0Y/airConditioner1/control, id: 350, message: {"action":"come_home","targetDevice":"airConditioner1"}
D/IoTEntryActivity: receive command: open airconditioner, count: 0
The above log represents the process in which the Door device is connected to MQTT successfully, publishes to its own topic, and carries the message with the action being come_home, and then the Airconditioner device also receives the homecoming topic message forwarded by the rule engine in the cloud, thus fulfilling the purpose of turning on the air conditioner upon homecoming.
In the device interconnection module, click Leave Home to trigger the Door device to publish to its own ${productId}/${deviceName}/event topic. As the rule engine in the cloud is configured to forward the data, it will forward messages from the topic to the Airconditioner device, and the Door device will disconnect from MQTT. Below is the sample code:
public void leaveRoom() {
...
MqttMessage message = new MqttMessage();
message.setPayload(LEAVE_HOME_MESSAGE.getBytes());
String topic = String.format("%s/%s/%s", PRODUCT_ID, DEVICE_NAME, "event");
mqttConnection.publish(topic, message, null); // Publish the message to its own topic which carries `LEAVE_HOME_MESSAGE` (leave_home)
closeConnection(); // Disconnect the `Door` device from MQTT
}
Observe the logcat log.
I/com.tencent.iot.hub.device.java.core.mqtt.TXMqttConnection: Starting publish topic: 9RW4A8OOFK/door1/event Message: {"action": "leave_home", "targetDevice": "airConditioner1"}
I/com.tencent.iot.hub.device.java.core.mqtt.TXMqttConnection: deliveryComplete, token.getMessageId:2
I/iot.scenarized.Door: onDisconnectCompleted, status[OK], msg[disconnected to ssl://9RW4A8OOFK.iotcloud.tencentdevices.com:8883]
I/TXMQTT_1.2.3: Received topic: XMN6AZ4M0Y/airConditioner1/control, id: 351, message: {"action":"leave_home","targetDevice":"airConditioner1"}
D/IoTEntryActivity: receive command: close airconditioner, count: 1
The above log represents the process in which the Door device subscribes and publishes to its own topic, carries the message message with the action being leave_home, and disconnects from MQTT, and then the Airconditioner device also receives the homeleaving topic message forwarded by the rule engine in the cloud, thus fulfilling the purpose of turning off the air conditioner upon homeleaving.