Bluetooth: Peripheral LBS

The peripheral LBS sample demonstrates how to use the LED Button Service (LBS).

Overview

When connected, the sample sends the state of Button 1 on the development board to the connected device, such as a phone or tablet. The mobile application on the device can display the received button state and can control the state of LED 3 on the development board.

Alternatively, you can use this sample to control the color of RGB LED on the nRF52840 Dongle.

Requirements

User interface

For nRF52840 Dongle:

RGB LED:
Red:

  • On when connected.

Green:

  • Controlled remotely from the connected device.

Button 1:

  • Sends a notification with the button state: “pressed” or “released”.

For Development Kit boards:

LED 1:

  • When the main loop is running (device is advertising), blinks with a period of 2 seconds, duty cycle 50%.

LED 2:

  • On when connected.

LED 3:

  • Controlled remotely from the connected device.

Button 1:

  • Sends a notification with the button state: “pressed” or “released”.

Building and Running

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

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

Minimal Build

The sample can be built with a minimum configuration as a demonstration of how to reduce code size and RAM usage.

west build samples/bluetooth/peripheral_lbs -- -DOVERLAY_CONFIG='minimal.conf'

Testing

After programming the sample to your dongle or development board, test it by performing the following steps. This testing procedure assumes that you are using nRF Connect for Mobile.

  1. Power on your development board or plug in your dongle.

  2. Connect to the device from nRF Connect (the device is advertising as “Nordic_Blinky”).

  3. Observe that the services of the connected device are shown.

  4. In “Nordic LED Button Service”, click the Play button for the “Button” characteristic.

  5. Press Button 1 either on the dongle or on the development board.

  6. Observe that notifications with the following values are received:

    • 00 when Button 1 is released,

    • 01 when Button 1 is pressed.

  7. Control the color of RGB LED on the dongle or status of LED 3 on the board by writing the following values to the “LED” characteristic in the “Nordic LED Button Service”:

    • 00 to switch the LED off on the board or turn on the red RGB LED on the dongle.

    • 01 to switch the LED on on the board or turn on the green RGB LED on the dongle.

  8. Observe that RGB LED on the dongle or LED 3 on the board corresponds to the value of the “LED” characteristic.

Dependencies

This sample uses the following nRF Connect SDK libraries:

In addition, it uses the following Zephyr libraries:

  • include/zephyr/types.h

  • lib/libc/minimal/include/errno.h

  • include/sys/printk.h

  • include/sys/byteorder.h

  • GPIO Interface

  • Bluetooth:

    • include/bluetooth/bluetooth.h

    • include/bluetooth/hci.h

    • include/bluetooth/conn.h

    • include/bluetooth/uuid.h

    • include/bluetooth/gatt.h