examples/nordic_softdevice_ble

This application demonstrates how to use the Nordic Semi nRF52 SoftDevice to implement a GATT peripheral. The example was written against Nordic SDK 15.0.0 and may or may not work with later SDK versions. Based on the way Nordic has been developing their SDK in the past, it is quite likely that this example will stop working at some point, probably with SDK 17 or 18.

The example has been tested with Nordic nRF52DK, but it should work also with nRF52840DK.

To test, you need a BLE central. For example, you can run Nordic nRF Connect on your iPhone or Android. Note that the iOS BLE stack is more picky than then Android one. Therefore it is quite easy to break the iOS functionality and render nRF connect on an iPhone nonfunctional while testing with Anrdoid will continue to work. At this writing, we are unaware of any good documentation about the differences, though.

Usage

1. Build, flash and start the application:

   export BOARD=nrf52dk
   make
   make flash
   make term

The term make target starts a terminal emulator for your board. It connects to a default port so you can see the debug output. Usually the port is /dev/ttyUSB0 in Linux or /dev/tty.usbmodem* in Mac OS X. If your port is named differently, the PORT=/dev/yourport variable can be used to override this.

2. Start nRF connect or similar

Let nRF connect to scan for the nearby Bluetooth devices. Select one named according to your compiled example; search for DEVICE_NAME in main.c. The default name is NepEmBLE.

When connected to the device, you should see a custom service identifier B131ABCD-7195-142B-E012-0808817F198D. This is basically a random 128-bit UUID. If you are building a service of your own, you should generate your own UUID and discard the default one, see ITU-T UUID generation page.

Inside the service, you will see two custom Characteristics: B131BBD0-7195-142B-E012-0808817F198D and B131BBCF-7195-142B-E012-0808817F198D. The former is used to read the state of the push buttons on the nRF52DK, the latter to set two of the LEDs there. (The first two LEDs are used by default to indicate that the demo has booted and whether it is service a connected central or not.)