nRF51 SDK v10.0.0
Heart Rate Application
This example requires one of the following SoftDevices: S110, S130, S310

Important: Before you run this example, make sure to program a SoftDevice.

The Heart Rate Application is an example that implements the Heart Rate profile using the hardware delivered in the nRF51 Development Kit.

The application includes the three services in the Heart Rate profile:

When the application starts, the Board Support Package is initialized. Next, three timers are started. These timers control the generation of various parts of the Heart Rate Measurement characteristic value:

Also, a timer for generating battery measurements is started.

The sensor measurements are simulated the following way:

When notification of Heart Rate Measurement characteristic is enabled, the Heart Rate Measurement, containing the current value for all the components of the Heart Rate Measurement characteristic, is notified each time the Heart Rate measurement timer expires. When notification of Battery Level characteristic is enabled, the Battery Level is notified each time the Battery Level measurement timer expires.

This application is not power optimized!
The application will stop advertising after 3 minutes and go to system-off mode. Push the button 1 to restart advertising.


The name of the example is ble_app_hrs_SoftDevice_Board, where SoftDevice is the SoftDevice that you are using and Board is the supported board. If you are not using the Keil Pack Installer, you can find the source code and project file of the example in the following folder: <InstallFolder>\examples\ble_peripheral\ble_app_hrs

Button assignments: BSP BLE Button Assignments.


Test the Heart Rate Application with the nRF Toolbox app, which is available on both iOS (Apple Store) and Android (Google Play).

You can also test the application with the Master Control Panel by performing the following steps:

  1. Compile and program the application. Observe that the BSP_INDICATE_ADVERTISING state is indicated.
  2. Connect to the device from Master Control Panel (the device will be advertising as 'Nordic_HRM'), then perform service discovery. Observe that the BSP_INDICATE_CONNECTED state is indicated.
  3. Click the 'Enable services' button on the Master Control Panel. Observe that Heart Rate notifications are received every second, and Battery Level notifications are received every two seconds.

This document was last updated on Mon Nov 9 2015.
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