Bluetooth: Central Heart Rate Monitor with Coded PHY

The Central Heart Rate Monitor with Coded PHY offers similar functionality to the Bluetooth: Central / Heart-rate Monitor sample from Zephyr. However, this sample specifically looks for heart rate monitors using LE Coded PHY.

Overview

The sample demonstrates a Bluetooth® LE Central role functionality by scanning for other Bluetooth LE devices that run a Heart Rate Server with LE Coded PHY support, which is not available in Zephyr Bluetooth LE Controller (See Bluetooth LE Controller for more information). It then establishes a connection to the first Peripheral device in range. It can be used together with the Bluetooth: Peripheral Heart Rate Monitor with Coded PHY sample.

Requirements

The sample supports the following development kits:

Hardware platforms

PCA

Board name

Build target

nRF5340 DK

PCA10095

nrf5340dk_nrf5340

nrf5340dk_nrf5340_cpuapp

nrf5340dk_nrf5340_cpuapp_ns

nRF52840 Dongle

PCA10059

nrf52840dongle_nrf52840

nrf52840dongle_nrf52840

nRF52840 DK

PCA10056

nrf52840dk_nrf52840

nrf52840dk_nrf52840

Note

If you use nRF5340 DK, the additional configuration of the network core will be taken from the child_image directory. For more details see: Image-specific variables.

The sample also requires a device running a Heart Rate Server with LE Coded PHY support to connect to. For example, another development kit running the Bluetooth: Peripheral Heart Rate Monitor with Coded PHY sample.

Building and running

This sample can be found under samples/bluetooth/central_hr_coded in the nRF Connect SDK folder structure.

See Building and programming an application for information about how to build and program the application.

Testing

After programming the sample to your development kit, you can test it by connecting to another development kit that runs the Bluetooth: Peripheral Heart Rate Monitor with Coded PHY.

  1. Connect to the kit that runs this sample with a terminal emulator (for example, PuTTY). See How to connect with PuTTY for the required settings.

  2. Reset the kit.

  3. Program the other kit with the Bluetooth: Peripheral Heart Rate Monitor with Coded PHY sample.

  4. Wait until the Coded advertiser is detected by the Central. In the terminal window, check for information similar to the following:

    Filters matched. Address: xx.xx.xx.xx.xx.xx (random) connectable: yes
Connection pending
Connected: xx.xx.xx.xx.xx.xx (random), tx_phy 4, rx_phy 4
The discovery procedure succeeded

  5. Observe that the received notifications are output in the terminal window:

    [SUBSCRIBED]
Heart Rate Measurement notification received:

  Heart Rate Measurement Value Format: 8 - bit
  Sensor Contact detected: 1
  Sensor Contact supported: 1
  Energy Expended present: 0
  RR-Intervals present: 0

  Heart Rate Measurement Value: 113 bpm

Dependencies

This sample uses the following nRF Connect SDK libraries:

In addition, it uses the following Zephyr libraries:

  • include/zephyr/types.h

  • include/errno.h

  • include/zephyr.h

  • include/sys/printk.h

  • include/sys/byteorder.h

  • Kernel Services:

    • include/kernel.h

  • Bluetooth:

  • include/bluetooth/bluetooth.h

  • include/bluetooth/conn.h

  • include/bluetooth/gatt.h

  • include/bluetooth/uuid.h