Connect a device to IoT Platform

Procedure

1. Download the C SDK for devices.

   1. Log on to the IoT Platform console.

   2. In the upper-left corner of the console, select the region where your instance is located. On the Instance Overview tab, click Public Instance.

   3. In the navigation pane on the left, click Documents & Tools. In the Device SDK section, under Link SDK, click Customize SDK.

   4. Customize and download the SDK.

      On the SDK generation page, configure the following parameters:

      • SDK Version: Select v4.x

      • Device OS: Select Linux

      • Device Hardware: Select Single-board system

      • Protocol: Select MQTT, version 3.1.1

      • Data Encryption: Select TLS-CA

      • Device Authentication: Select Device Secret

      • Advanced Capabilities: Select Thing Specification Language model

      After you complete the settings, click Start Generation.

2. Unzip the C SDK file and modify the device certificate information.

   Download data_model_basic_demo.c and use it to replace the file in \LinkSDK\demos. Update the following parameters:

   char *product_key       = "a2***";
   char *device_name       = "device1";
   char *device_secret     = "8c684ef***";
   ...
   ...
   char  *mqtt_host = "a2***.iot-as-mqtt.cn-shanghai.aliyuncs.com";

   Parameter	Example	Description
   mqtt_host	New public instances:iot-cn-***.mqtt.iothub.aliyuncs.com Old public instances:a2***.iot-as-mqtt.cn-shanghai.aliyuncs.com	The MQTT ingest endpoint for the device. New public instances: On the Instance Details page, click View Development Configurations. The endpoint appears on the Development Configurations panel. Old public instances: The endpoint format is${YourProductKey}.iot-as-mqtt.${YourRegionId}.aliyuncs.com. View instance endpoints.
   product_key	a2***	The device certificate saved when you added the device. You can also view the certificate on the Device Details page in the IoT Platform console. Obtain a device certificate.
   device_name	device1
   device_secret	8c684ef***

3. On the Linux virtual machine, install the required software.

   sudo apt-get install -y build-essential make gcc

4. Upload the modified LinkSDK directory to your Linux virtual machine.

5. In the SDK root directory /LinkSDK, run the make command to compile the sample program.

   make clean
   make

   The compiled binary data-model-basic-demo is in ./output.

6. Run the sample program.

   ./output/data-model-basic-demo

   Expected output:

   root@xxx:~/linkSDK# ./output/data-model-basic-demo
   [1637041632.700][LK-0313] MQTT user calls aiot_mqtt_connect api, connect
   [1637041632.700][LK-032A] mqtt host: axxx.iot-as-mqtt.cn-shanghai.aliyuncs.com
   [1637041632.700][LK-0317] user name: device1&axxx,0
   [1637041632.700][LK-0318] password: 86761xxx¥21D
   establish tcp connection with server(host='axxx.iot-as-mqtt.cn-shanghai.aliyuncs.com', port=[443])
   success to establish tcp, fd=3
   local port: 35604
   [1637041632.711][LK-1000] establish mbedtls connection with server(host='axxx.iot-as-mqtt.cn-shanghai.aliyuncs.com', port=[443])
   [1637041632.766][LK-1000] success to establish mbedtls connection, (cost 45252 bytes in total, max used 47988 bytes)
   [1637041632.811][LK-0313] MQTT connect success in 108 ms
   AIOT_MQTTEVT_CONNECT
   [1637041632.811][LK-0309] pub: /sys/axxx/device1/thing/event/property/post
   
   [LK-030A] > 7B 22 69 64 22 3A 22 31  22 2C 22 76 65 72 73 69 | {"id":"1","versi
   [LK-030A] > 6F 6E 22 3A 22 31 2E 30  22 2C 22 70 61 72 61 6D | on":"1.0","param
   [LK-030A] > 73 22 3A 7B 22 4C 69 67  68 74 43 75 72 72 65 6E | s":{"LightCurren
   [LK-030A] > 74 22 3A 20 31 2E 35 7D  2C 22 73 79 73 22 3A 7B | t": 1.5},"sys":{
   [LK-030A] > 22 61 63 6B 22 3A 31 7D  7D                       | "ack":1}}
   
   [1637041632.833][LK-0309] pub: /sys/axxx/device1/thing/event/property/post_reply
   
   [LK-030A] < 7B 22 63 6F 64 65 22 3A  32 30 30 2C 22 64 61 74 | {"code":200,"dat
   [LK-030A] < 61 22 3A 7B 7D 2C 22 69  64 22 3A 22 31 22 2C 22 | a":{},"id":"1","
   [LK-030A] < 6D 65 73 73 61 67 65 22  3A 22 73 75 63 63 65 73 | message":"succes
   [LK-030A] < 73 22 2C 22 6D 65 74 68  6F 64 22 3A 22 74 68 69 | s","method":"thi
   [LK-030A] < 6E 67 2E 65 76 65 6E 74  2E 70 72 6F 70 65 72 74 | ng.event.propert
   [LK-030A] < 79 2E 70 6F 73 74 22 2C  22 76 65 72 73 69 6F 6E | y.post","version
   [LK-030A] < 22 3A 22 31 2E 30 22 7D                           | ":"1.0"}
   
   [1637041632.833][LK-0A08] DM recv generic reply
   demo_dm_recv_handler, type = 0
   msg_id = 1, code = 200, data = {}, message = success

7. In the IoT Platform console, go to the Public Instance page. Verify the device status.

   • Choose Device Management > Devices. On the Devices page, enter device1 in the DeviceName search box to find the target device. Verify that the device status is Online.

   • Click View in the Actions column. On the Device Details page, click the TSL Data tab and then Running Status.

     The data_model_basic_demo.c sample reports the operating current value.

     On the Running Status tab, the Operating Current property displays a value of 1.5 A, indicating that the device has successfully reported this property value.