#include <activity_recognition.h>

Detecting Activities

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

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

   activity_h handle;
   activity_create(&handle);
   

2. 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 registered 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 [3] and wearable [4] applications) can be used in place of the ACTIVITY_WALK value.

   activity_start_recognition(handle, ACTIVITY_WALK, example_activity_callback, NULL);
   

3. When the registered 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 */
   }
   

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

   activity_stop_recognition(handle);
   activity_release(handle);