Bluetooth¶

Zephyr comes integrated with a feature-rich and highly configurable Bluetooth stack:

Bluetooth 4.2 compliant
Bluetooth Controller support (LE Link Layer)
- Currently supports Nordic Semiconductor nRF51 and nRF52
Generic Access Profile (GAP) with all possible roles
- Peripheral & Central
- Observer & Broadcaster
GATT (Generic Attribute Profile)
- Server (to be a sensor)
- Client (to connect to sensors)
Pairing support, including the Secure Connections feature from Bluetooth 4.2
IPSP/6LoWPAN for IPv6 connectivity over Bluetooth LE
- IPSP node sample application in samples/bluetooth/ipsp
Clean HCI driver abstraction
- 3-Wire (H:5) & 5-Wire (H:4) drivers available
- Local controller support also as an HCI driver
Raw HCI interface to run Zephyr as a Controller instead of a full Host stack
- Possible to export HCI over a physical transport
- samples/bluetooth/hci_uart sample for HCI over UART
- samples/bluetooth/hci_usb sample for HCI over USB
Verified with multiple popular controllers
Highly configurable
- Features, buffer sizes/counts, stack sizes, etc.

Source tree layout¶

The stack is split up as follows in the source tree:

subsys/bluetooth/host: The host stack. This is where the HCI command & event handling as well as connection tracking happens. The implementation of the core protocols such as L2CAP, ATT & SMP is also here.
subsys/bluetooth/controller: Bluetooth Controller implementation. Implements the controller-side of HCI, the Link Layer as well as access to the radio transceiver.
include/bluetooth/: Public API header files. These are the header files applications need to include in order to use Bluetooth functionality.
drivers/bluetooth/: HCI transport drivers. Every HCI transport needs its own driver. E.g. the two common types of UART transport protocols (3-Wire & 5-Wire) have their own drivers.
samples/bluetooth/: Sample Bluetooth code. This is a good reference to get started with Bluetooth application development.
tests/bluetooth/: Test applications. These applications are used to verify the functionality of the Bluetooth stack, but are not necessary the best source for sample code (see samples/bluetooth instead).
doc/subsystems/bluetooth/: Extra documentation, such as PICS documents.