Activity Recognition: Detecting Device Activities

This tutorial demonstrates how you can manage and monitor various system information and attached devices.

Warm-up

Become familiar with the Activity Recognition API basics by learning about:

• Detecting Activities

  Detect user activities.

Detecting Activities

To set and unset callback functions for the activity monitor and retrieve details from the received activity data:

1. To use the activity recognition-related features of the Activity Recognition API (in mobile and wearable applications), include the <activity_recognition.h> header file in your application:

   #include <activity_recognition.h>
   

2. Create a handle for activity monitoring using the activity_create() function:

   activity_h handle;
   activity_create(&handle);
   

3. To subscribe to notifications about specific activity state changes, invoke the activity_start_recognition() function to register a callback function.

   When specific activity data is received, the example_activity_callback callback is invoked.

   The following example starts the activity monitor to receive notifications when the ACTIVITY_WALK activity is detected. Any of the activity_type_e enumerators (in mobile and wearable applications) can be used in place of the ACTIVITY_WALK value.

   activity_start_recognition(handle, ACTIVITY_WALK, example_activity_callback, NULL);
   

4. When the example_activity_callback() callback is invoked, the current activity is delivered as a parameter, and you can extract the accuracy of the recognized activity:

   void example_activity_callback(activity_type_e activity, const activity_data_h data, double timestamp, activity_error_e error, void *user_data)
   {
      int result;
   
      activity_accuracy_e accuracy;
      result = activity_get_accuracy(data, &accuracy);
   
      if (result != ACTIVITY_ERROR_NONE) 
      {
         // Error handling
      }
   }

5. When activity monitoring is no longer used, unset the callback function and destroy the handle:

   activity_stop_recognition(handle);
   activity_release(handle);