Gateway application example

You can download the IoT Platform SDK. For more information, see Get the SDK.

• For the SDK that includes AliOS Things, the gateway sample application is located in the Products/example/linkkit_gateway/ directory. The code files are as follows.

  gateway_cmds.c
  gateway_cmds.h
  gateway_entry.c
  gateway_entry.h
  gateway_main.c
  gateway_main.h
  gateway_ut.c
  gateway_ut.h
  gateway_api.c
  gateway_api.h

• For the SDK that does not include AliOS Things, the gateway sample application is located in the examples/linkkit/gateway/ directory. The code files are as follows.

  gateway_entry.c
  gateway_entry.h
  gateway_main.c
  gateway_main.h
  gateway_ut.c
  gateway_ut.h
  gateway_api.c
  gateway_api.h

  Note

  Compared with the SDK version that includes AliOS Things, this version does not include the gateway_cmds.c or gateway_cmds.h files. The other code files are the same.

The following sections describe the files in the gateway sample application.

gateway_entry.c

gateway_entry.c is the main entry file for the application.

int application_start(int argc, char **argv)
{
... ... ... ... ... ... ... ... ... 
    // Set the default log level
#ifdef DEFAULT_LOG_LEVEL_DEBUG
    IOT_SetLogLevel(IOT_LOG_DEBUG);
#else
#ifdef CSP_LINUXHOST
    IOT_SetLogLevel(IOT_LOG_DEBUG);
#else
    IOT_SetLogLevel(IOT_LOG_INFO);
#endif
#endif
    // Load the four-tuple information. You must implement this function.
    load_device_meta_info();

... ... ... ... ... ... ... ... ...
    // Register a callback function for a successful cloud connection to perform OTA initialization.
    IOT_RegisterCallback(ITE_MQTT_CONNECT_SUCC, mqtt_connected_event_handler);

    // Register serial port commands. The code is in gateway_cmds.c.
#ifdef CONFIG_AOS_CLI
    gateway_register_cmds();
#endif

... ... ... ... ... ... ... ... ... 
    // The loop of the main function.
    aos_loop_run();

    return 0;
}

gateway_main.c

Because some sub-device network connection operations are synchronous and blocking, this file creates the following two threads:

• user_dispatch_yield thread: Executes the Link Kit SDK code and the registered user callback functions.

• gateway_main main thread: Calls Link Kit SDK interfaces and handles communication with sub-devices.

gateway_cmds.c

This file contains code for command-line features that facilitate testing and debugging.

gateway_ut.c

This file contains user test code. For example, you can use this code to simulate sub-device information using key-value pairs, bring a sub-device online after you retrieve the topology list, and simulate adding a sub-device when the gateway permits new sub-devices to join.

gateway_api.c

This file encapsulates SDK interface functions for sub-device operations. It supports features such as adding, deleting, and resetting sub-devices, and querying sub-device IDs. You can use these interface functions directly.

• Add a sub-device

  To add a sub-device, you must make three SDK interface calls.

  • Call IOT_Linkkit_Open: Adds the sub-device to the local data structure of the gateway.

  • Call IOT_Linkkit_Connect: Registers the sub-device and adds its topology relationship to the cloud.

  • Call IOT_Linkkit_Report: Notifies the cloud that the sub-device is online.

  GATEWAY_API int gateway_add_subdev(iotx_linkkit_dev_meta_info_t *subdev_mate)
  {
  ... ... ... ... ... ... ... ... ...
      devid = IOT_Linkkit_Open(IOTX_LINKKIT_DEV_TYPE_SLAVE, subdev_mate);
  ... ... ... ... ... ... ... ... ...
      res = IOT_Linkkit_Connect(devid);
  ... ... ... ... ... ... ... ... ...
      res = IOT_Linkkit_Report(devid, ITM_MSG_LOGIN, NULL, 0);
  ... ... ... ... ... ... ... ... ...
  }

• Add sub-devices in a batch

  • The IOT_Linkkit_Report( ... ITM_MSG_CONNECT_SUBDEV ...) function supports adding up to five sub-devices in a single batch.

  • If the sub-devices are successfully added in a batch, call IOT_Linkkit_Report(subdev_id, ITM_MSG_LOGIN, NULL, 0) to bring the corresponding sub-devices online.

  GATEWAY_API int gateway_add_multi_subdev(int master_devid, iotx_linkkit_dev_meta_info_t *subdev_list, int subdev_num)
  {
  ... ... ... ... ... ... ... ... ...
      connect_times = subdev_num / GATEWAY_SUBDEV_ONE_TIME_CONNECT_MAX_NUM + (((subdev_num % GATEWAY_SUBDEV_ONE_TIME_CONNECT_MAX_NUM) == 0) ? 0 : 1);
  
      for (index = 0; index < connect_times; index++)
      {
          ... ... ... ... ... ... ... ... ...
          res = IOT_Linkkit_Report(master_devid, ITM_MSG_CONNECT_SUBDEV, (unsigned char *)p_cur_subdev, sizeof(iotx_linkkit_dev_meta_info_t) * cur_subdev_num);
          if (res == SUCCESS_RETURN)
          {
              // Bring sub-devices online in a batch
              res = IOT_Linkkit_Report(subdev_id, ITM_MSG_BATCH_LOGIN, (unsigned char *)p_cur_subdev, sizeof(iotx_linkkit_dev_meta_info_t) * cur_subdev_num);
              ... ... ... ... ... ... ... ... ...
          }
      }
  
      return res;
  }

• Delete a sub-device

  Call the IOT_Linkkit_Report(subdev_id, ITM_MSG_DELETE_TOPO, (unsigned char *)subdev_mate, sizeof(iotx_linkkit_dev_meta_info_t)) function to delete the topology relationship between a sub-device and the gateway. This operation also releases the resources of the sub-device on the gateway.

  Note

  When you delete a sub-device, the system first searches for the sub-device by its ProductKey and DeviceName. If the sub-device is found, it is deleted. If the sub-device is not found, the system continues the search using the first parameter, subdev_id.

  GATEWAY_API int gateway_del_subdev(iotx_linkkit_dev_meta_info_t *subdev_mate)
  {
  ... ... ... ... ... ... ... ... ...
      //Here pk and dn of subdev is priorior than subdev id
      ret = IOT_Linkkit_Report(subdev_id, ITM_MSG_DELETE_TOPO, (unsigned char *)subdev_mate, sizeof(iotx_linkkit_dev_meta_info_t));
  ... ... ... ... ... ... ... ... ...
  }

• Reset a sub-device

  Call the IOT_Linkkit_Report(subdev_id, ITM_MSG_SUBDEV_RESET, (unsigned char *)subdev_mate, sizeof(iotx_linkkit_dev_meta_info_t)) function to reset a sub-device. This operation deletes the topology relationship of the sub-device with the gateway, unbinds the sub-device from the user account, and releases the resources of the sub-device on the gateway.

  Note

  When you reset a sub-device, the system first searches for the sub-device by its ProductKey and DeviceName. If the sub-device is found, it is reset. If the sub-device is not found, the system continues the search using the first parameter, subdev_id.

  GATEWAY_API int gateway_reset_subdev(iotx_linkkit_dev_meta_info_t *subdev_mate)
  {
  ... ... ... ... ... ... ... ... ...
      //Here pk and dn of subdev is priorior than subdev id
      ret = IOT_Linkkit_Report(subdev_id, ITM_MSG_SUBDEV_RESET, (unsigned char *)subdev_mate, sizeof(iotx_linkkit_dev_meta_info_t));
  ... ... ... ... ... ... ... ... ...
  }

• Query the DeviceID of a sub-device

  Call the IOT_Linkkit_Query(master_devid, ITM_MSG_QUERY_SUBDEV_ID, (unsigned char *)subdev_mate, sizeof(iotx_linkkit_dev_meta_info_t)); function to query the DeviceID of a sub-device based on its ProductKey and DeviceName. The DeviceID is a positive integer that serves as a data structure index.

  GATEWAY_API int gateway_query_subdev_id(int master_devid, iotx_linkkit_dev_meta_info_t *subdev_mate)
  {
  ... ... ... ... ... ... ... ... ...
      subdev_id = IOT_Linkkit_Query(master_devid, ITM_MSG_QUERY_SUBDEV_ID, (unsigned char *)subdev_mate, sizeof(iotx_linkkit_dev_meta_info_t));
  ... ... ... ... ... ... ... ... ...
  }

• Bring sub-devices online in batches

  This interface function splits the input array of sub-devices into groups of five for batch login.

  
  GATEWAY_API int gateway_batch_login(int master_devid, iotx_linkkit_dev_meta_info_t *subdev_list, int subdev_num)
  {
  ... ... ... ... ... ... ... ... ...
      for (index = 0; index < connect_times; index++)
      {
  ... ... ... ... ... ... ... ... ...
          res = IOT_Linkkit_Report(subdev_id, ITM_MSG_BATCH_LOGIN, (unsigned char *)p_cur_subdev, sizeof(iotx_linkkit_dev_meta_info_t) * cur_subdev_num);
  ... ... ... ... ... ... ... ... ...
      return res;
  }

• Log out of sub-devices in a batch

  This interface function splits the input array of sub-devices into groups of five for batch logout.

  GATEWAY_API int gateway_batch_logout(int master_devid, iotx_linkkit_dev_meta_info_t *subdev_list, int subdev_num)
  {
  ... ... ... ... ... ... ... ... ...
      for (index = 0; index < connect_times; index++)
      {
  ... ... ... ... ... ... ... ... ...
          res = IOT_Linkkit_Report(subdev_id, ITM_MSG_BATCH_LOGOUT, (unsigned char *)p_cur_subdev, sizeof(iotx_linkkit_dev_meta_info_t) * cur_subdev_num);
  ... ... ... ... ... ... ... ... ...
      }
  
      return res;
  }