In addition to the basic features of general products, a gateway product can also be bound to products that cannot directly access the internet and used to exchange data with IoT Hub on behalf of such products (i.e., subdevices). This document describes how to connect a gateway product to IoT Hub over the MQTT protocol for proxied subdevice connection/disconnection and message sending/receiving.
To try out the gateway feature, you need to create a gateway product in the console and bind a subproduct and a subdevice. For more information, please see Device Connection Preparations and Gateway Product Connection.
Edit the configuration information in the app-config.json file.
{
"PRODUCT_ID": "",
"DEVICE_NAME": "",
"DEVICE_PSK": "",
"SUB_PRODUCT_ID": "",
"SUB_DEV_NAME": "",
"SUB_PRODUCT_KEY": "",
"TEST_TOPIC": "",
"SHADOW_TEST_TOPIC": "",
"PRODUCT_KEY": ""
}
You need to enter the PRODUCT_ID (gateway product ID), DEVICE_NAME (gateway device name), DEVICE_PSK (gateway device key), SUB_PRODUCT_ID (subproduct ID), SUB_DEV_NAME (subdevice name), and SUB_PRODUCT_KEY (subdevice key) parameters of a key-authenticated device in app-config.json.
Please connect the device to MQTT for authenticated connection as instructed in Device Connection Through MQTT over TCP first.
Run the demo and click Connect Subdevice in the basic feature module to connect the subdevice. Below is the sample code:
mMQTTSample.setSubdevOnline(); // Connect the subdevice
The following logcat log represents the process in which the subdevice is connected successfully. In the console, you can see that the status of the device has been updated to online.
D/TXMQTT1.2.3: The hashed information is {9RW4A8OOFKdoor1=com.tencent.iot.hub.device.java.core.gateway.TXGatewaySubdev@9a3c239}
set 9RW4A8OOFK & door1 to Online
I/com.tencent.iot.hub.device.java.core.mqtt.TXMqttConnection: Starting publish topic: $gateway/operation/AP9ZLEVFKT/gateway1 Message: {"type":"online","payload":{"devices":[{"product_id":"9RW4A8OOFK","device_name":"door1"}]}} {"type":"online","payload":{"devices":[{"product_id":"9RW4A8OOFK","device_name":"door1"}]}}
D/TXMQTT: onPublishCompleted, status[OK], topics[[$gateway/operation/AP9ZLEVFKT/gateway1]], userContext[], errMsg[publish success]
D/TXMQTT: receive command, topic[$gateway/operation/result/AP9ZLEVFKT/gateway1], message[{"type":"online","payload":{"devices":[{"product_id":"9RW4A8OOFK","device_name":"door1","result":0}]}}]
Please connect the device to MQTT for authenticated connection as instructed in Device Connection Through MQTT over TCP first.
Run the demo and click Disconnect Subdevice in the basic feature module to disconnect the subdevice. Below is the sample code:
mMQTTSample.setSubDevOffline(); // Disconnect the subdevice
The following logcat log represents the process in which the subdevice is disconnected successfully. In the console, you can see that the status of the device has been updated to offline.
D/TXMQTT1.2.3: Try to find 9RW4A8OOFK & door1
The hashed information is {9RW4A8OOFKdoor1=com.tencent.iot.hub.device.java.core.gateway.TXGatewaySubdev@27282a6}
set 9RW4A8OOFK & door1 to offline
I/com.tencent.iot.hub.device.java.core.mqtt.TXMqttConnection: Starting publish topic: $gateway/operation/AP9ZLEVFKT/gateway1 Message: {"type":"offline","payload":{"devices":[{"product_id":"9RW4A8OOFK","device_name":"door1"}]}}
D/TXMQTT: onPublishCompleted, status[OK], topics[[$gateway/operation/AP9ZLEVFKT/gateway1]], userContext[], errMsg[publish success]
D/TXMQTT: receive command, topic[$gateway/operation/result/AP9ZLEVFKT/gateway1], message[{"type":"offline","payload":{"devices":[{"product_id":"9RW4A8OOFK","device_name":"door1","result":0}]}}]