nRF5340 Bluetooth Controller with Support for LE ISO Timesync
This fork of the Zephyr HCI UART example adds a custom HCI Command to allow for timesync between the Bluetooth Host and the Bluetooth Controller. When the HCI LE Read ISO Clock command is received, the Controller toggles a GPIO and returns its current Bluetooth LE ISO Clock in the Command Complete Event.
It has been tested on the nRF5340 Audio DK, but it should work with any nRF5340 dev kit.
Requirements
- nRF Connect SDK v2.8 or newer
HCI LE Read ISO Clock Command
- OGF: 0x3f, OCF: 0x200
- Parameters: Flags (1 Octet) unused
- Response: HCI Command Complete Event with status and 4 bytes timestamp in microseconds
nRF5340 Development Kit
The first Virtual UART (UART1, ...) is Zephyr UART 1 The second Virtual UART (UART2, ...) is Zephyr UART 0
Pinout
Signal direction as seen from the nRF5340.
| PIN | Arduino | MCU | Direction |
|---|---|---|---|
| TX | D0 | P1.00 | out |
| RX | D1 | P1.01 | in |
| RTS | D7 | P1.11 | out |
| CTS | D8 | P1.10 | in |
| Time Sync | D10 | P1.06 | out |
HCI over USB CDC
west build --pristine -b nrf5340dk/nrf5340/cpuapp -- -DEXTRA_DTC_OVERLAY_FILE=usb.overlay -DOVERLAY_CONFIG=overlay-usb.conf
HCI over UART 0 connected to second Virtual UART in J-Link Probe
west build --pristine -b nrf5340dk/nrf5340/cpuapp
- HCI over second Virtual port / UART 0
- Boot banner on Arduino Header UART (P1.01) / UART 1
HCI over UART 1 connected to first Virtual UART in J-Link Probe as well as Arduino Headers
west build --pristine -b nrf5340dk/nrf5340/cpuapp -- -DEXTRA_DTC_OVERLAY_FILE=uart1.overlay
- No Boot Banner on Arduino Header UART
nRF5340 Audio DK
The first UART (UART1, P1.04, P1.05) is only available via test points (TP60, TP61, ...) The second UART (UART2, P1.08, P1.09) is connected to the Arduino headers.
Pinout
Signal direction as seen from the nRF5340.
| PIN | Arduino | MCU | Direction |
|---|---|---|---|
| TX | D0 | P1.09 | out |
| RX | D1 | P1.08 | in |
| RTS | D7 | P1.11 | out |
| CTS | D8 | P1.10 | in |
| Time Sync | D10 | P1.01 | out |
HCI over USB CDC
west build --pristine -b nrf5340_audio_dk/nrf5340/cpuapp -- -DEXTRA_DTC_OVERLAY_FILE=usb.overlay -DOVERLAY_CONFIG=overlay-usb.conf
HCI over UART 0 connected to Virtual UART in J-Link Probe
west build --pristine -b nrf5340_audio_dk/nrf5340/cpuapp
HCI over UART 1 connected to Virtual UART in J-Link Probe as well as Arduino Headers
Release build:
west build --pristine -b nrf5340_audio_dk/nrf5340/cpuapp -- -DEXTRA_DTC_OVERLAY_FILE=uart1.overlay
Debug build:
west build --pristine -b nrf5340_audio_dk/nrf5340/cpuapp -- -DEXTRA_DTC_OVERLAY_FILE=uart1.overlay -DOVERLAY_CONFIG=debug.conf
To use UART 1 via Arduino headers, the virtual UART of the J-Link probe needs to be disabled, e.g. with the JLink Configuration Tool.