Heart Rate Service (HRS)

This module implements the Heart Rate Service with the Heart Rate Measurement and Body Sensor Location characteristics.

Overview 

During initialization, the module adds the Heart Rate Service, the Heart Rate Measurement and Body Sensor Location characteristics to the Bluetooth LE stack database. Optionally, it also adds the Body Sensor Location characteristics.

If enabled, a notification of the Heart Rate Measurement characteristic is sent when the application calls the ble_hrs_heart_rate_measurement_send() function.

The Heart Rate Service also provides a set of functions for manipulating the various fields in the Heart Rate Measurement characteristic, as well as setting the Body Sensor Location characteristic value.

If an event handler is supplied by the application, the Heart Rate Service will generate Heart Rate Service events to the application.

Configuration 

Set the CONFIG_BLE_HRS Kconfig option to enable the service.

You can use the CONFIG_BLE_HRS_MAX_BUFFERED_RR_INTERVALS Kconfig option to set the size of RR Interval buffers.

Initialization 

The service instance is declared using the BLE_HRS_DEF macro, specifying the name of the instance. The service is initialized by calling the ble_hrs_init() function. See the ble_hrs_config struct for configuration details, in addition to the HRS specification.

Usage 

Events from the service are forwarded through the event handler specified during initialization. For a full list of events, see the ble_hrs_evt_type enum.

The ble_hrs_conn_params_evt() function must be called on Bluetooth: Connection Parameters events to forward the event to the HRS service. The application can send heart rate measurements by calling the ble_hrs_heart_rate_measurement_send() function. This requires notifications to be enabled.

The ble_hrs_rr_interval_add() function can be called to add a RR Interval measurement to the RR Interval buffer. Use the ble_hrs_rr_interval_buffer_is_full() function to check if the RR Interval buffer is full.

The state of the sensor contact supported bit and sensor contact detected bit can be set by calling the ble_hrs_sensor_contact_supported_set() and ble_hrs_sensor_contact_detected_update() functions, respectively. To set the body sensor location, call the ble_hrs_body_sensor_location_set() function.