Bluetooth: Radio Notification callback

This sample demonstrates how to use the Radio Notification callback feature. It uses the GATT Latency Service and the GATT Latency Client to showcase how you can use this feature to minimize the time between data sampling and data transmission.

Requirements

The sample supports the following development kits:

Hardware platforms	PCA	Board name	Board target
nRF54L15 PDK	PCA10156	nrf54l15pdk	nrf54l15pdk/nrf54l15/cpuapp
nRF54H20 DK	PCA10175	nrf54h20dk	nrf54h20dk/nrf54h20/cpurad
nRF5340 DK	PCA10095	nrf5340dk	nrf5340dk/nrf5340/cpunet
nRF52 DK	PCA10040	nrf52dk	nrf52dk/nrf52832
nRF52840 DK	PCA10056	nrf52840dk	nrf52840dk/nrf52840

You can use any two of the development kits mentioned above and mix different development kits.

Additionally, the sample requires a connection to a computer with a serial terminal for each of the development kits.

Note

The feature involves triggering a (D)PPI task directly from the SoftDevice Controller link layer. The application and SoftDevice Controller are supposed to be running on the same core.

Building and running

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

To build the sample, follow the instructions in Building an application for your preferred building environment. See also Programming an application for programming steps and Testing and optimization for general information about testing and debugging in the nRF Connect SDK.

Note

When building repository applications in the SDK repositories, building with sysbuild is enabled by default. If you work with out-of-tree freestanding applications, you need to manually pass the --sysbuild parameter to every build command or configure west to always use it.

Testing

After programming the sample to both development kits, perform the following steps to test it:

1. Connect to both kits with a terminal emulator (for example, nRF Connect Serial Terminal). See Testing and optimization for the required settings and steps.

2. Reset both kits.

3. In one of the terminal emulators, type c to start the application on the connected board in the central role.

4. In the other terminal emulator, type p to start the application in the peripheral role.

5. Observe that latency measurements are printed in the terminals.

Sample output

The result should look similar to the following output.

For the central:

Starting radio notification callback sample.
I: SoftDevice Controller build revision:
I: d6 da c7 ae 08 db 72 6f |......ro
I: 2a a3 26 49 2a 4d a8 b3 |*.&I*M..
I: 98 0e 07 7f             |....
I: HW Platform: Nordic Semiconductor (0x0002)
I: HW Variant: nRF52x (0x0002)
I: Firmware: Standard Bluetooth controller (0x00) Version 214.51162 Build 1926957230
I: Identity: FA:BB:79:57:D6:45 (random)
I: HCI: version 5.4 (0x0d) revision 0x11fb, manufacturer 0x0059
I: LMP: version 5.4 (0x0d) subver 0x11fb
Choose device role - type c (central) or p (peripheral):
Central. Starting scanning
Scanning started
Device found: CF:99:32:A5:4B:11 (random) (RSSI -43)
Connected: CF:99:32:A5:4B:11 (random)
Service discovery completed
Latency: 3771 us, round trip: 53771 us
Latency: 3741 us, round trip: 53741 us
Latency: 3741 us, round trip: 53741 us
Latency: 3741 us, round trip: 53741 us
Latency: 3771 us, round trip: 53771 us
Latency: 3771 us, round trip: 53771 us
Latency: 3741 us, round trip: 53741 us
Latency: 3741 us, round trip: 53741 us
Latency: 3741 us, round trip: 53741 us
Latency: 3771 us, round trip: 53771 us
Latency: 3771 us, round trip: 53771 us
Latency: 3741 us, round trip: 53741 us
Latency: 3741 us, round trip: 53741 us

For the peripheral:

Starting radio notification callback sample.
I: SoftDevice Controller build revision:
I: d6 da c7 ae 08 db 72 6f |......ro
I: 2a a3 26 49 2a 4d a8 b3 |*.&I*M..
I: 98 0e 07 7f             |....
I: HW Platform: Nordic Semiconductor (0x0002)
I: HW Variant: nRF52x (0x0002)
I: Firmware: Standard Bluetooth controller (0x00) Version 214.51162 Build 1926957230
I: Identity: CF:99:32:A5:4B:11 (random)
I: HCI: version 5.4 (0x0d) revision 0x11fb, manufacturer 0x0059
I: LMP: version 5.4 (0x0d) subver 0x11fb
Choose device role - type c (central) or p (peripheral):
Peripheral. Starting advertising
Advertising started
Connected: FA:BB:79:57:D6:45 (random)
Service discovery completed
Latency: 3649 us, round trip: 53649 us
Latency: 3649 us, round trip: 53649 us
Latency: 3619 us, round trip: 53619 us
Latency: 3649 us, round trip: 53649 us
Latency: 3649 us, round trip: 53649 us
Latency: 3649 us, round trip: 53649 us
Latency: 3649 us, round trip: 53649 us
Latency: 3619 us, round trip: 53619 us
Latency: 3649 us, round trip: 53649 us
Latency: 3649 us, round trip: 53649 us
Latency: 3649 us, round trip: 53649 us
Latency: 3649 us, round trip: 53649 us
Latency: 3649 us, round trip: 53649 us
Latency: 3649 us, round trip: 53649 us

Dependencies

This sample uses the following nRF Connect SDK libraries:

• GATT Latency Service

• GATT Latency Client

This sample uses the following sdk-nrfxlib libraries:

• SoftDevice Controller

In addition, it uses the following Zephyr libraries:

• include/console.h

• Kernel Services:

  • include/kernel.h

• include/sys/printk.h

• include/zephyr/types.h

• API:

  • include/bluetooth/bluetooth.h

  • include/bluetooth/conn.h

  • include/bluetooth/gatt.h

  • include/bluetooth/scan.h

  • include/bluetooth/gatt_dm.h

  • include/bluetooth/evt_cb.h