Sensor fusion algorithm interface

The sensor fusion algorithm interface enables the plug-in sensors, such as pedometer and activity recognition and the application of the fusion algorithms. More...

Overview

The sensor fusion algorithm interface enables the plug-in sensors, such as pedometer and activity recognition and the application of the fusion algorithms.

The fusion algorithm is available in a library format. The APIs are designed to feed the physical sensor data into fusion algorithms and obtain the results based on the various application needs.

How to use sensor fusion algorithm interface

Below is an example of the pedometer fusion algorithm (requires accelerometer of 50Hz sampling rate) registration. The steps are shown below:

• Step 1. Prepare the sensor_descriptor_t for the pedometer.
• Step 2. Set the required input sensor.
• Step 3. Register the pedometer fusion algorithm using sensor_fusion_algorithm_register_type().
• Step 4. Register the data buffer using sensor_fusion_algorithm_register_data_buffer(). Please refer to sensor_manager_t in [sdk_root]/middleware/MTK/sensor_subsys/src/sensor_manager.c for data buffer allocation.
• Sample code:

  static sensor_input_list_t input_comp_acc;
  static int32_t get_pedometer_result(sensor_data_t *const output)
  {
      // Return the pedometer result.
      return 1;
  }
  
  static int32_t pedometer_process_data(const sensor_data_t *input_list, void *reserved)
  {
      int32_t count = input_list->data_exist_count;
      sensor_data_unit_t *data_start = input_list->data;
  
      while (count != 0) {
          // Process the input data.
          sensor_fusion_algorithm_notify(SENSOR_TYPE_PEDOMETER); // Call for data update notification.
          data_start++;
          count--;
      }
      return 1;
  }
  
  static int32_t pedometer_operate(int32_t command, void *buffer_out, int32_t size_out, \
                                   void *buffer_in, int32_t size_in)
  {
      // Process the customized parameter.
      return 0;
  }
  
  const sensor_descriptor_t pedometer_desp = {
      SENSOR_TYPE_PEDOMETER,
      1, // version.
      SENSOR_REPORT_MODE_ON_CHANGE, // sensor_report_mode_t.
      &input_comp_acc, // Required input sensor list.
      pedometer_operate,
      get_pedometer_result,
      pedometer_process_data,
      0 // Not used
  };
  
  int pedometer_register()
  {
      int ret;
  
      input_comp_acc.input_type = SENSOR_TYPE_ACCELEROMETER;
      // Set accelerometer sensor sampling at 20ms interval (50Hz) with a batch timeout of 200ms.
      input_comp_acc.sampling_delay = 20; // 20ms interval, 50Hz sampling rate.
      input_comp_acc.timeout = 200;
      input_comp_acc.next_input = NULL;
  
      ret = sensor_fusion_algorithm_register_type(&pedometer_desp);
      if (ret < 0) {
          // Registration type error handling.
      }
      ret = sensor_fusion_algorithm_register_data_buffer(SENSOR_TYPE_PEDOMETER, 1);
      if (ret < 0) {
          // Registration data buffer error handling.
      }
      return ret;
  }

Functions
int32_t	sensor_fusion_algorithm_register_type (const sensor_descriptor_t *desp)
	Registers fusion algorithm of the specified sensor_descriptor. More...
int32_t	sensor_fusion_algorithm_register_data_buffer (uint32_t sensor_type, uint32_t exist_data_count)
	Registers the required data buffer of fusion algorithm of the specified sensor type. More...
int32_t	sensor_fusion_algorithm_notify (uint32_t sensor_type)
	For fusion algorithm to notify sensor manager of sensor event. More...

Modules
	Enum
	Struct
	Typedef

Function Documentation

int32_t sensor_fusion_algorithm_notify

(

uint32_t

sensor_type

)

For fusion algorithm to notify sensor manager of sensor event.

Parameters

[in]

sensor_type

is the specified sensor type.

Returns

>=0, if the operation completed successfully.

int32_t sensor_fusion_algorithm_register_data_buffer	(	uint32_t	sensor_type,
		uint32_t	exist_data_count
	)

Registers the required data buffer of fusion algorithm of the specified sensor type.

Parameters

[in]	sensor_type	is the specified sensor type.
[in]	exist_data_count	is the required data buffer count.

Returns

>=0, if the operation completed successfully.

int32_t sensor_fusion_algorithm_register_type

(

const sensor_descriptor_t *

desp

)

Registers fusion algorithm of the specified sensor_descriptor.

Parameters

[in]

desp

is the specified sensor_descriptor.

Returns

>=0, if the operation completed successfully.