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Overview

This sample app for the reel board showcases Bluetooth Mesh.

The app starts off as a regular Bluetooth GATT peripheral application. Install the “nRF Connect” app on your phone (available both for Android and iOS) to access the service that the app exposes. The service can also be accessed with any Bluetooth LE GATT client from your PC, however these instructions focus on the necessary steps for phones.

Steps to set up

  1. On your phone, use the nRF Connect app to Scan for devices and look for “reel board”

  2. Connect to the device. You’ll see a single service - select it

  3. Request to write to the characteristic by pressing on the upward pointing arrow symbol

  4. Select “Text” to enter text instead of hex

  5. Enter your name (or any other arbitrary text). Multiple words separated by spaces are possible. The font used on the reel display allows three rows of up to 12 characters wide text. You can force line breaks with a comma.

  6. Press “Send” - this will trigger pairing since this is a protected characteristic. The passkey for the pairing will be shown on the board’s display. Enter the passkey in your phone.

  7. Once pairing is complete the board will show the text you sent. If you’re not happy with it you can try writing something else.

  8. When you’re happy with the text, disconnect from the board (exit the app or go back to the device scan page)

  9. Once disconnected the board switches over to Bluetooth Mesh mode, and you can’t connect to it anymore over GATT.

If you configure multiple boards like this they can communicate with each other over mesh: by pressing the user button on the board the first word (name) of the stored text will be sent to all other boards in the network and cause the other boards to display “<name> says hi!”.

To reset a board to its initial state (disable mesh, erase the stored text, and make it connectable over GATT):

  1. Keep the user button pressed when powering on (or press the reset button when powered)

  2. Wait until “Resetting Device” is shown

See also

Monochrome Character Framebuffer
Bluetooth Mesh
Generic Attribute Profile (GATT)
Bluetooth APIs