Dual-mode Bluetooth stack, with small memory footprint.
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Latest commit f7013e3 Feb 23, 2017 @mringwal mringwal Merge branch 'develop'


Note: Major API Changes. For older projects, you may use the v0.9 branch. Please see Migration notes

Welcome to BTstack

BTstack is BlueKitchen's implementation of the official Bluetooth stack. It is well suited for small, resource-constraint devices such as 8 or 16 bit embedded systems as it is highly configurable and comes with an ultra small memory footprint. A minimal configuration for an SPP server on a MSP430 can run in 32 kB FLASH and only 4 kB of RAM.

It connects to the Bluetooth modules via a different Bluetooth HCI transport layers (e.g., HCI H4 UART and H5 the "Tree-Wire" protocol, HCI H2 USB). Various platforms can be easily targeted by providing the necessary UART, CPU, and CLOCK implementations.

On smaller embedded systems, a minimal run loop implementation allows to use BTstack without a Real Time OS (RTOS). If a RTOS is already provided, BTstack can be integrated and run as a single thread.

On larger systems, BTstack provides a daemon that connects to a Bluetooth module. Multiple applications can communicate with this daemon over different inter-process communication methods.

BTstack supports both, the Central and the Peripheral Role of Bluetooth 4.2 Low Energy specification. It can be configures as both a single mode or a dual mode stack.

BTstack is free for non-commercial use. For commercial use, tell us a bit about your project to get a quote. It has been qualified with the the Bluetooth SIG for GAP, IOP, HFP, HSP, SPP, PAN profiles and GATT, SM of the Bluetooth 4.2 LE Central and Peripheral roles (QD ID 25340).


Discussion and Community Support

BTstack Google Group

Supported Protocols and Profiles

Protocols: L2CAP, RFCOMM, SDP, BNEP, ATT, SM (incl. LE Secure Connections).


Coming next: A2DP, AVRCP, HID, HOGP, BLE Mesh, and more.

For information on MFi/iAP2 support, please contact us.

Evaluation Platforms

Embedded Platforms:

Status Platform
EZ430-RF256x Bluetooth Evaluation Tool for MSP430
MSP430F5438 Experimenter Board for MSP430 with Bluetooth CC2564 Module Evaluation Board
MSP-EXP430F5529LP LaunchPad with Bluetooth CC2564 Module Evaluation Board and EM Adapter BoosterPack with additional 32768Hz quartz oscillator
STM32 Nucleo development board NUCLEO-F103RB with Bluetooth CC2564 Module Evaluation Board and EM Adapter BoosterPack with additional 32768Hz quartz oscillator
Microchip's PIC32 Bluetooth Audio Development Kit
RedBear Duo with Broadcom BCM43438 A1

Other Platforms:

Status Platform
posix: Unix-based system talking to Bluetooth module via serial port
libusb: Unix-based system talking via USB Bluetooth dongle
daemon: TCP and Unix domain named socket client-server architecture supporting multiple clients
java: Java wrapper for daemon
iOS: daemon for iOS jailbreak devices, C client-server API
mtk: daemon for rooted Android devices, based on Mediatek MT65xx processor, Java and C client-server API
wiced: Broadcom platforms that support the WICED SDK

Supported Chipsets

Chipset Type HCI Transport SCO over HCI (2) BTstack folder Comment
Broadcom UART Dual mode H4, H5 Probably bcm Max UART baudrate 2 mbps
Broadcom USB Dongles Dual mode USB Yes bcm
CSR UART Dual mode H4, H5 No (didn't work) csr
CSR USB Dongles Dual mode USB Yes csr
EM 9301 LE SPI n.a. em9301 Custom HCI SPI implementation
Nordic nRF LE H4 n.a. Requires custom HCI firmware
STM STLC2500D Classic H4 No (didn't try) stlc2500d Custom deep sleep management not supported
Toshiba TC35661 Dual mode H4 No (didn't try) tc3566 HCI version not tested.
TI CC256x, WL183x Dual mode H4, H5, eHCILL Yes cc256x Also WL185x, WL187x, and WL189x

More infos on supported chipsets

Source Tree Overview

Path Description
chipset Support for individual Bluetooth chipsets
doc Sources for BTstack documentation
example Example applications available for all ports
platform Support for special OSs and/or MCU architectures
port Complete port for a MCU + Chipset combinations
src Bluetooth stack implementation
test Unit and PTS tests
tool Helper tools for BTstack